*TM 3-4240-346-20&P
TM 09204A/09205A-20&P/2
UNIT MAINTENANCE MANUAL
(INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST)
FOR
CHEMICAL BIOLOGICAL MASK: FIELD M40A1
(4240-01-370-3821-SMALL)
(4240-01-370-3822-MEDIUM)
(4240-01-370-3823--LARGE)
CHEMICAL BIOLOGICAL MASK: COMBAT VEHICLE M42A2
(4240-01-413-4100-SMALL)
(4240-01-413-4101-MEDIUM)
(4240-01-413-4102--LARGE)
* This manual supersedes the M40A1 part of TM 3-4240-300-20&P / TM 09204A/09205A-20&P/2, 31 July
96, and the M42A2 part of TM 3-4240-343-20&P/TM 09204A/09205A-20&P/2, 31 July 96.
WARNING - This document contains export-controlled technical data whose export is restricted by the Army Export
Control Act (Title 22, U.S.S.S., Sec 2751 et seq.) or Executive order 12470. Violation of these export laws is subject to
severe criminal penalties.
DISTRIBUTION STATEMENT - Distribution authorized to U. S. Government agencies and their contractors to
protect technical or operational information This determination was made on 24 June 1987. Other requests for this
document will be referred to: Technical Director, U.S. Army, Edgewood Research, Development & Engineering Center,
ATN: SCBRD-ENL-V, Aberdeen Proving Ground, MD 21010-5423.
DESTRUCTION NOTICE  Destroy by any method that will prevent disclosure of contents or reconstruction of the
document.
HEADQUARTERS, DEPARTMENT OF THE ARMY
AND, HEADQUARTERS, MARINE CORPS
1 AUGUST 1998
PCN 182 092041 00
WARNINGS point out dangerous steps in the procedures in this manual Your safety depends on following the instructions
included in all WARNINGS. Several general WARNINGS are included below:
" The mask will not be fully effective in confined spaces when the oxygen content of the air is too low. The CB mask
has only been tested and verified to protect against all known military agents.
" DO NOT touch your skin (or the soldier) with n-Amyl acetate (banana oil). It could irritate the skin. Wear rubber
gloves.
" DO NOT smoke around n-Amyl acetate (banana oil), it is flammable.
" DO NOT test mask assembly with n-Amyl acetate (banana oil) in a closed, poorly ventilated area. Test outdoors or in
a well-aired room, n-Amyl acetate may be toxic if inhaled in quantity.
" DO NOT wear contact lenses (soft or hard) while wearing CB Protective Masks. Inadequate oxygen supply to the
corneal surface, exposure to dust, dirt, and smoke/gas may cause serious vision loss or eye damage. Soldiers
requiring vision correction are provided optical inserts for their protective masks.
HEALTH/ENVIRONMENTAL HAZARD
" There are two Mask Filter Canisters, the C2 and the C2A1. The C2 canister contains Chromium VI and damaged or
unusable canisters are considered Hazardous Waste. (Chromium VI is a known carcinogen if inhaled or swallowed.)
" The C2A1 canister is chromium-free but must continue to be disposed of in accordance with State and Local
Environmental Laws.
" DO NOT throw away damaged or unusable canisters as ordinary trash.
" DO turn in damaged or unusable canisters to your hazardous waste management office or Defense Reutilization and
Marketing Office (DRMO).
FIRST AID
For first aid refers to FM 21-11.
SAFETY DATA SHEETS
http://www.apgea.army.mil/RDA/pmnbc/c2aldisp.html
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
TECHNICAL MANUAL
DEPARTMENT OF THE ARMY
AND HEADQUARTERS, MARINE CORPS
Washington, D.C., 1 AUGUST 1998
UNIT MAINTENANCE MANUAL
(INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST)
FOR
CHEMICAL BIOLOGICAL MASK: FIELD M40A1
(4240-01-370-3821--SMALL)
(4240-01-370-3822--MEDIUM)
(4240-01-370-3823--LARGE)
CHEMICAL BIOLOGICAL MASK: COMBAT VEHICLE M42A2
(4240-01-413-4100--SMALL)
(4240-01-413-4101--MEDIUM)
(4240-01-413-4102--LARGE)
REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes or if you know of a way to improve the procedures, please let us
know. Mail you letter, DA Form 2028 (Recommended Changes to Publications and Blank Forms), or DA Form 2028-2
located in the back of this manual direct to: Technical Director, U.S. Army, Edgewood Research, Development &
Engineering Center, ATTN: SCBRD-ENL-V, Aberdeen Proving Ground, MD 21010-5423.
Marine Corps Users - Submit NAVMC FORM 10772 directly to Commander, Marine Corps Logistics Base (Code 850), 814
Radford Blvd, AIbany, GA 31704-5000. In addition, a copy of the NAVMC 10772 or naval message should be sent to
MARCORSYSCOM (Code CSLENBC), 2033 Barnett Ave., Suite 315, Quantico, VA 22134-5010.
In either case, a reply will be sent to you.
i
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TABLE OF CONTENTS
HOW TO USE THIS MANUAL .................................................................................................................. iii
CHAPTER 1 INTRODUCTION.................................................................................................................. 1-1
SECTION I. GENERAL INFORMATION .................................................................................................. 1-1
SECTION II. EQUIPMENT DESCRIPTION AND DATA ............................................................................ 1-2
SECTION III. PRINCIPLES OF OPERATION ........................................................................................... 1-12
CHAPTER 2 UNIT MAINTENANCE INSTRUCTION ................................................................................. 2-1
SECTION I. REPAIR PARTS, SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT........................... 2-3
SECTION II. SERVICE UPON RECEIPT .................................................................................................. 2-3
SECTION III. EQUIPMENT/USER FITTING INSTRUCTIONS ................................................................... 2-19
SECTION IV. TROUBLESHOOTING ........................................................................................................ 2-29
SECTION V. PREVENTIVE MAINTENANCE CHECKS AND SERVICES .................................................. 2-39
SECTION VI. HOSE ASSEMBLY CONVERSION ..................................................................................... 2-45
SECTION VII. MAINTENANCE PROCEDURES ....................................................................................... 2-53
SECTION VIII. CLEANING AND SANITIZING ........................................................................................... 2-77
SECTION IX. PREPARATION FOR STORAGE OR SHIPMENT .............................................................. 2-95
APPENDIX A - REFERENCES ................................................................................................................ A-1
APPENDIX B - MAINTENANCE ALLOCATION CHART (MAC) ............................................................... B-1
APPENDIX C - UNIT MAINTENANCE REPAIR PARTS AND SPECIAL TOOLS
LIST......................................................................................................................... C-1
APPENDIX D - EXPENDABLE AND DURABLE ITEMS LIST .................................................................. D-1
CROSS-REFERENCE INDEXES ............................................................................................................. I-1
INDEX....................................................................................................................................................... INDEX 1
ii
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HOW TO USE THIS MANUAL
The safest, easiest, and best way to do maintenance on the Chemical-Biological Mask, M40A1/M42A2 is to use this manual.
Learning to use this TM is as easy as reading through the next few pages. Knowing what's in this manual and how to use it
will save you time and work, and will help you avoid exposing yourself to unnecessary hazards while you do your job.
ORGANIZATION
Page ii has a table of contents to provide easy access to the manual. Pages are numbered consecutively within each
chapter; each page number is prefixed with a chapter number or appendix letter. For example, page 5 of Chapter 2 is
numbered 2-5 and page 3 of appendix B is numbered B-3.
This manual is divided into two chapters, four appendixes, and an alphabetical index. Chapter 2 has an index at the
beginning of the chapter to provide easy access to its content. Each chapter is divided into sections. Chapter 1 contains
general information pertaining to location of forms, destruction of Army material, how to store and ship the mask, procedures
for reporting any improvement recommendations you may have, as well as, corrosion prevention and control. Chapter 2
gives unit maintenance instructions and includes four types of maintenance activities. These are: Service Upon Receipt;
Troubleshooting or location of faults by symptoms you can detect; Preventive Maintenance Checks and Service (PMCS);
and Maintenance Procedures that are used to correct faults and replace failed parts. Within the Troubleshooting and
maintenance portions of this manual, you will find the material in functional group code order like the Maintenance Allocation
Chart in Appendix B of this TM. This allows the TM to be aligned with its applicable Repair Parts and Special Tools List
(RPSTL). For information on how to use the RPSTL, refer to the introduction in Appendix C.
Each section in this manual is further divided into three parts. The first addresses procedures which are the same regardless
of which mask you are using. The second part addresses those tasks which are peculiar to the M40A1 and the third
addresses those peculiar to the M42A2. Therefore, depending on which mask you are using, you must follow the
instructions in the general part and the part which is peculiar to your mask.
For instance, if you have the M40A1 mask, you must do the Before PMCS checks under COMMON and those checks listed
under M40A1 PECULIAR Those tasks listed under M42A2 PECULIAR are not required.
Those tasks which are considered to be COMMON and apply to either mask are illustrated using the M42A2.
However, the differences between the M40A1 and M42A2 do not impact on the task, and, in many cases, you will
not be able to tell from the illustration which mask is being illustrated.
HOW TO FIND PROCEDURES
If you're using the manual to perform Troubleshooting, go to Section IV, and read TROUBLESHOOTING PROCEDURES
and proceed according to the instructions there. If you're going to do Scheduled Maintenance, you can turn directly to
Preventive Maintenance Checks and Services (PMCS), Section V, and proceed according to the instructions there.
If you are using the manual to perform repair or replacement of a part that you already know is bad, you would start by
locating the part to be replaced in the Alphabetical index located at the back of this manual. Look in the Alphabetical Index
for a key noun from the mask system or part nomenclature. The Alphabetical Index lists each task under one or more
headings also giving the location for the installation and removal of some part. For example, the procedure for CLEANING
AND SANITIZING would be listed under "C" for Cleaning.
Once you've located the correct procedure, read through it to determine if you have everything you need to perform the job.
Make sure all the Equipment Conditions have been met. Familiarize yourself with the potential hazards described by the
WARNINGS and CAUTIONS. You must familiarize yourself with the entire maintenance procedure before beginning the
maintenance task.
iii
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HOW TO USE A MAINTENANCE PROCEDURE
The first page of a maintenance procedure lists everything you will need to perform that procedure. The following
paragraphs describe all the blocks of information you will find there.
TOOLS. Individual tools from your mechanic's tool kit will not be listed under this heading. If any tools from this kit are
required, the tool kit itself will be listed as the first item. Special tools, and tools from any other source will be listed with a
reference to a specific item and appendix number. The referenced appendix will provide you with the necessary information
to find or make the tool.
SUPPLIES. If any expendable or consumable supplies are needed to perform the task, they will be listed under this heading
along with the quantity in parentheses and a reference to a figure item and appendix in the back of the TM. The referenced
appendix will give you the detailed information necessary to requisition the supply if you don't have it on hand. Replacement
parts are not normally listed under this heading. The inspection steps in the removal or disassembly procedure will tell you
which parts to replace. Mandatory repair parts ( parts that are destroyed in disassembly or not normally reused, such as
gaskets and lock washers) are listed under this heading by their nomenclature only. Refer to Repair Parts and Special Tools
List (RPSTL), Appendix C for information you need on repair parts.
iv (v blank)
TM 3-4240-346-20&P
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CHEMICAL BIOLOGICAL MASKS
M40A1
M42A2
1-0
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
CHAPTER 1
INTRODUCTION
SECTION I. GENERAL INFORMATION
1-1. SCOPE
a. Type of Manual. Unit maintenance.
b. Model Numbers and Equipment Name. Chemical-biological (CB ) mask: field M40AI, and CB mask combat vehicle
M42A2.
c. Purpose of Equipment. Protects the face, eyes, and lungs from field concentrations of CB agents, toxins, and
radioactive fallout particles.
1-2. MAINTENANCE FORMS, RECORDS, AND REPORTS
a. Department of the Army forms and procedures used for equipment maintenance will be those prescribed by DA
PAM 738-750, The Army Maintenance Management System (TAMMS), as contained in the Maintenance
Management update.
b. Marine Corps forms and procedures used for equipment maintenance are prescribed in TM 4700-15/1_.
1-3. DESTRUCTION OF ARMY MATERIAL TO PREVENT ENEMY USE
" Refer to TM 43-0002-31 for methods of destruction.
1-4. PREPARATION FOR STORAGE OR SHIPMENT
" Refer to Chapter 2, Section IX, for preparation for storage or shipment.
1-5. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIR)
a. If you have ideas on how the M40A 1 or the M42A2 masks can be changed or maintained more effectively, let us
know. Send us an EIR. You, the user, are the only one who can tell us what you don't like about your equipment. Let
us know why you don't like the design. Put it on an SF 368 (Quality Deficiency Report). Mail it to us at Director, US
Army Armament and Chemical Acquisition and Logistics Activity, ATTN: AMSTA-AR-QAW-A (RI), Rock Island, IL
61299-7630. We'll send you a reply.
b. Marine Corps users shall submit a Standard Form 368 (SF368) in accordance with MCO4855. 10 directly to:
Commander, Marine Corps Logistics Base (Code 856), 814 Radford Blvd., Albany, GA 31704-5000. We will send
you a reply.
1-6. CORROSION PREVENTION AND CONTROL (CPC)
a. CPC of Army material is a continuing concern. It is important that any corrosion problems with this item be reported
so that the problem can be corrected and improvements can be made to prevent the problem in future items.
b. While corrosion is typically associated with rusting of metals, it can also include deterioration of other materials such
as rubber and plastic. Unusual cracking, softening, swelling, or breaking of these materials may be a corrosion
problem.
c. If a corrosion problem is identified, it can be reported using a Quality Deficiency Report, SF 368. Use of key words
such as "corrosion", "rust", "deterioration", or "cracking" will assure that the information is identified as a CPC
problem.
d. The form should be submitted to Director, US Army Armament and Chemical Acquisition and Logistics Activity,
ATTN: AMSTA-AR-QAW-A (RI), Rock Island, IL 61299-7630.
e. Marine Corps Units report CPC problems using SF 368 and procedures prescribed in TM 4700-15/1_.
1-1
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TM 09204A/09205A - 20&P/2
SECTION II. EQUIPMENT DESCRIPTION AND DATA
1-7. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES.
COMMON
The lightweight, CB masks (M40A1 / M42A2 ) are easy to assemble for transport and storage. The mask assembly is kept
dry, when required by climate and mission, by a waterproof bag and stored in a carrier made of mildew-resistant, water
repellent, coated nylon.
The facepiece is made of silicone rubber with an inturned sealing surface so it can provide protection to face, eyes, and
respiratory tract from CB agents, toxins and radioactive particles. The mask assembly is not intended for use in an oxygen
deficient environment. Nor is it intended to provide protection against carbon monoxide or ammonia It forms a comfortable
seal on a soldier's face as it protects against adverse elements. The mask assembly is equipped with both front and side
voicemitters for ease of communication and an outlet valve body with a drinking system. To ensure a comfortable fit, the
mask assembly is issued in three sizes: small, medium and large which are marked with S, M and L on the forehead to
show sizing. It is also equipped with clear and neutral gray outserts to protect the eyelens from scratches, reduce sun glare
and prevent fogging in cold weather.
The masks have a second skin, universal second skin, or universal second skin (USMC) which fits to the facepiece and
protects the facepiece from liquid agents, and a quick doff hood made of lightweight, butyl rubber-coated fabric, which
provides protection to the head and neck from liquid toxic chemical agents. The second skin, universal second skin, or
universal second skin (USMC) is issued in two sizes: small and medium/large which are marked S and M/L on the exterior
left cheek.
M40A1 PECULIAR
The CB mask, M40A1, consists of a facepiece and filter canister.
M42A2 PECULIAR
The CB mask, M42A2, consists of a facepiece, canister carrier and hose assembly . The M42A2 masks has microphone
communication capability that can couple with on board communication systems, through the Combat Vehicle
Communications (CVC) helmet.
1-8. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS
COMMON
a. FACE PIECE ASSEMBLY
" FACEPIECE (1). The following components are molded/assembled into the silicone rubber facepiece: buckle tabs,
facepiece openings for eyelens, nosecup, voicemitters, outlet valve, and filter canister/hose connectors.
" HEAD HARNESS (2). Constructed of elastic webbing sewn to a rectangular head pad and buckled to facepiece.
The ends of the head harness straps have metal strap end clips to prevent fraying of the elastic webbing. Ends of
the head harness straps pass through buckles at the two forehead, temple and cheek positions. Elastic webbing
connects the two forehead straps and holds them in proper alignment when the mask assembly is worn. Head
harness straps attached to buckles at the ends of the tabs permit adjustment to obtain proper fit of the mask
assembly.
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TM 09204A/09205A - 20&P/2
" NOSECUP ASSEMBLY (3). Made of soft rubber, fits over the soldier's nose and mouth. Diverts exhaled air toward
the outlet valve to reduce fogging of the eyelens.
" NOSECUP VALVE SEATS (4). Each of two nosecup valve seats holds silicone rubber NOSECUP VALVE DISK (5),
which allows filtered air to enter nosecup and prevent moist exhaled air from fogging the eyelens in cold weather.
" INTERNAL DRINK TUBE (6). Allows the soldier to drink while wearing the mask assembly.
" AIRFLOW DEFLECTOR (7), located inside the mask assembly, directs inhaled air over eyelens to reduce fogging.
The airflow deflector also supports the inlet valve disk and the inlet valve body.
" INLET VALVE BODY (8) and INLET VALVE DISK (9), fits into the airflow deflector, allows filtered air to enter the
mask assembly and prevent moist exhaled air from entering the filter canister.
" OUTLET VALVE COVER (10). Protects outlet valve disk and outlet valve housing from damage.
" RETAINER (11). Holds external drink tube quick disconnect coupling.
" OUTLET VALVE DISK (12) and OUTLET VALVE HOUSING (13). Located behind outlet valve cover; releases
exhaled air and closes on inhalation to prevent contaminated air from entering mask assembly.
" FRONT (14) AND SIDE VOICEMITTERS (15). Transmits the soldier's voice outside the mask assembly.
" EXTERNAL DRINK TUBE (16). The External Drink Tube is used to connect the mask assembly to the M1 Canteen
cap for drinking. It consists of a length of hose and a quick disconnect coupling half (17) that fits into the external
drink tube retainer.
" DURABILITY ENHANCEMENT BAND (18). Band placed around outlet valve housing to ensure seal is maintained.
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TM 09204A/09205A - 20&P/2
1-8. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (CONT)
COMMON (CONT)
b. FILTER CANISTER (19) filters out CB agents and other particles from contaminated air.
NOTE
The soldier may be issued either the one piece hood OR the quick doff hood and
second skin OR universal second skin and quick doff hood or hooded over-
garment OR the universal second skin (USMC) and hooded overgarment. They
are identical in function and effectiveness. However, the one piece hood may not
be removed during decon operations.
c. ONE PIECE HOOD (20). Provides protection to the head and neck against liquid toxic chemical agents encountered
in field operations. Made of lightweight butyl rubber-coated fabric. It is attached to the mask assembly during use
and stowed in mask carrier.
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d. QUICK DOFF HOOD.
" QUICK DOFF HOOD (21). Is made of butyl rubber-coated fabric, which protects area of neck and head that is not
covered by mask assembly against CB agents, toxins, and radioactive fallout particles.
" ELASTIC AROUND OPENING (22). Attaches quick doff hood to the second skin. It enables easy removal of the
quick doff hood.
" ELASTIC AROUND NECK (23). Draws quick doff hood close to the neck to protect from CB agents.
" UNDERARM STRAPS (24). Retain quick doff hood on the shoulders. Plastic fasteners (25) are used to attach the
straps.
e. UNIVERSAL SECOND SKIN (26). Is made of butyl rubber and covers the mask assembly. It provides additional
protection against liquid agents. (Rubber catches and ridges are no longer needed because the universal second
skin is now larger.)
" Interfaces with hooded overgarments.
" Extends beyond the mask assembly.
" Interfaces with QDH..
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TM 09204A/09205A - 20&P/2
1-8. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS--(CONT )
COMMON (CONT)
f. SECOND SKIN ( M40A 1/ M42A2).
" SECOND SKIN (27). Is made of butyl rubber, and covers the mask assembly. It provides additional protection
against liquid agents.
" RUBBER CATCHES (28). Used to retain the quick doff hood on the mask assembly.
" The RIDGE (29) is also used to retain the quick doff hood.
g. UNIVERSAL SECOND SKIN (USMC only) (30). Is made of butyl rubber and covers the facepiece. It provides
additional protection against liquid agents. (Rubber catches and ridges are no longer needed because the universal
second skin is now larger.)
" Interfaces with hooded overgarments.
" Extends beyond the mask facepiece.
" Interfaces with the QDH.
h. Outserts have RUBBER RINGS (31) that fit over mask assembly eyelens rings to secure outserts to mask
assembly. The CLEAR OUTSERTS (32) and NEUTRAL GRAY OUTSERTS (33) prevent scratching of eyelens
from scratches and reduce fogging of eyelens in cold weather. The neutral gray outserts are used to reduce sun
glare.
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i. M1 WATERPROOF BAG (34). The folded waterproof bag and a small envelope containing the RUBBER BANDS
(35) are packed in carrier. The waterproof bag keeps the mask dry when required by climate and mission.
Instructions for use are printed on the waterproof bag.
j. FACEFORM(36)
" Holds mask assembly in proper shape when stored longer than 30 days.
M40A1 PECULIAR
NOTE
The soldier may be issued either mask carrier. Major differences
are size and accessory stowage locations.
k. Mask Carrier is made of mildew-resistant, water-repellant fabric. It has adjustable straps. It is closed with a flap held
by hook and pile material.
" IMPROVED FIELD MASK CARRIER (37) is designed to serve the field mask only. It has a larger velcro closing
surface, the AQD opening has been eliminated, the ID area is now camouflaged, the stiffeners have been removed,
it is wider and not as deep, and the interior pockets are larger.
" FIELD MASK CARRIER (38) was designed to serve field and combat vehicle masks.
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1-8. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS--(CONT )
M42A2 PECULIAR
I. DETACHABLE MICROPHONE (39). Located in the recess of the front voicemitter.
j. CANISTER CARRIER Improved (40) - Original (41)
NOTE
You may have been issued the original canister carrier or the
product improved model of the canister carrier. They are
interchangeable.
" The IMPROVED CANISTER CARRIER (40) is larger and interfaces with the a C2/C2A1 filter canisters, as well as, a
variety of North Atlantic Treaty Organization (NATO) filter canisters. The cover now screws on rather than attaching
with lug bolts, there is now a slip ring within the cover and the AQD is detachable and rotates.
" The ORIGINAL CANISTER CARRIER (41) interfaces with the C2/C2AI filter canisters only.
" ARMOR QUICK DISCONNECT (42). Attached to the canister cover (43) and permits the filter canister to be coupled
to a vehicle's Gas Particulate Filter Unit (GPFU).
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c. HOSE ASSEMBLY (44). The hose assembly connects the filter canister and canister carrier to the mask assembly.
" M42A2 - The hose assembly is attached to the mask assembly with the STAR KNOB (45). The hose assembly is
removable and can be relocated on left or right side of the mask assembly.
NOTE
The soldier may be issued either mask carrier. Major differences
are size and accessory stowage locations.
d. Mask Carrier is made of mildew-resistant, water-repellant fabric. It has adjustable straps. It is closed with a flap held
by hook and pile material.
" COMBAT VEHICLE MASK CARRIER (46). This mask carrier has been redesigned. It is now shaped to aid in
stowing the filter canister and hose, the velcro closing area has been enlarged to prevent dirt from entering the
mask carrier, the exterior pouch has been removed, the ID area is now camouflaged, the stiffeners have been
removed and the interior pockets are larger. It was designed to serve the combat vehicle mask only.
" FIELD MASK CARRIER (47) was designed to serve field and combat vehicle masks.
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1-9 DIFFERENCE BETWEEN MODELS
This chart shows major equipment and differences between the M40A1 and M42A2.
Table 1-1. Differences Between Models
CHEMICAL
MASK FEATURES BIOLOGICAL MASK
M40A1 M42A2
Facepiece X X
Filter canister is connected to end coupling of hose assembly
X
Detachable star knob hose assembly
X
Filter Canister attached directly to facepiece X
Hood (One-Piece) X
X
Quick Doff Hood X
X
Second Skin X
X
Universal Second Skin X
X
Universal Second Skin (USMC only) X
X
Clear/Neutral Outserts X
X
Detachable Microphone (External)
X
Front and Side Voicemitter X
X
Field Mask Carrier X
X
Improved Field Mask Carrier X
Combat Vehicle Mask Carrier
X
Operation Capabilities:
Combat Vehicle X
X
Transportable and stored in carrier X
X
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1-10 EQUIPMENT DATA
a. Tabulated Data
Weight (with carrier and accessories):
M40A1 mask. 3.8 lbs. (1.73 kg)
M42A2 mask. 4.5 lbs. (2.05 kg)
Dimensions:
M40A1 mask Mask with carrier...12 x 14 x4.5 in. (30.5 x 35.6 x 11.4 cm.)
M42A2 mask Mask with carrier...12x 14 x4.5 in. (30.5 x 35.6 x 11.4 cm.)
b. Shipping and Storage Data.
Shipping and Storage Data is identical for the M40A1 and M42A2 masks.
Number and type of pack: 10 per fiberboard container, 1 per fiberboard box.
Fiberboard container:
Dimensions: 34.375 x 22 x 16.75 in. (87 x 55.9 x 425 cm)
1-11
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SECTION III. PRINCIPLES OF OPERATION
1-11 PRINCIPLES OF OPERATION
a. M40A1 PRINCIPLES OF OPERATION
(1). Air enters the FILTER CANISTER (1), which is screwed into the side of the mask. The filter canister filters out CB
agents, toxins, and radioactive fallout particles from contaminated air. Air then passes over the AIRFLOW
DEFLECTOR (2) which is located inside the facepiece and on the same side as the filter canister. The air then
moves into the eye area of the facepiece.
(2). From the eye area, air enters the NOSECUP (3) through NOSECUP VALVES (4). Filtered air from the nosecup is
inhaled by the soldier. Exhaled air is passed through the nosecup area and out through the OUTLET VALVE (5).
The OUTLET VALVE COVER (6) protects the outlet valve from contamination and damage, and provides a retainer
for the external drink tube.
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b. M42A2 PRINCIPLES OF OPERATION
(1). Air enters the filter canister, which is held in the CANISTER CARRIER (7). The filter canister filters out CB agents,
toxins, and radioactive fallout particles from contaminated air. Air then passes through the HOSE (8) and
DEFLECTOR (9) which is located inside the mask assembly and on the same side as the hose assembly. The air
then moves into the eye area of the mask assembly.
(2). From the eye area, air enters the NOSECUP (10) through NOSECUP VALVES (11). Filtered air from the nosecup is
inhaled by the soldier. Exhaled air is passed through the nosecup area and out through the OUTLET VALVE (12).
The OUTLET VALVE COVER (13) protects the outlet valve from contamination and damage, and provides a
retainer for the external drink tube.
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CHAPTER 2 UNIT MAINTENANCE INSTRUCTIONS
Table of Contents
Para. Page
SECTION I. REPAIR PARTS, SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT............... 2-3
2-1. COMMON TOOLS AND EQUIPMENT ................................................................................................................... 2-3
2-2. SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT ...................................................................................... 2-3
2-3. REPAIR PARTS..................................................................................................................................................... 2-3
SECTION II. SERVICE UPON RECEIPT.......................................................................................... 2-3
2-4. GENERAL.............................................................................................................................................................. 2-3
2-5. SERVICE UPON RECEIPT OF MATERIAL............................................................................................................ 2-3
2-6. IDENTIFYING AN INDIVIDUAL'S MASK .............................................................................................................. 2-18
SECTION III. EQUIPMENT/USER FITTING INSTRUCTIONS........................................................ 2-19
2-7. ADJUSTING MASK ASSEMBLY AT INITIAL FITTING.......................................................................................... 2-19
2-8. CHECKING MASK ASSEMBLY FOR PROPER FUNCTION................................................................................. 2-23
2-9. CHECKING DRINKING SYSTEM FOR PROPER FUNCTION.............................................................................. 2-28
SECTION IV. TROUBLESHOOTING.............................................................................................. 2-29
2-10. TROUBLESHOOTING PROCEDURES.............................................................................................................. 2-29
SECTION V. PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS) ....................... 2-39
2-11. INTRODUCTION TO PMCS TABLE................................................................................................................... 2-39
2-12. PMCS PROCEDURES....................................................................................................................................... 2-39
SECTION VI. CONVERSION PROCEDURES................................................................................ 2-45
2-13. LEFT/RIGHT FILTER CANISTER/HOSE ASSEMBLY CONVERSION................................................................ 2-45
2-14. M40A1 TO M42A2 CONVERSION ..................................................................................................................... 2-51
2-15. M42A2 TO M40A1 CONVERSION ..................................................................................................................... 2-52
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Table of Contents
Para Page
SECTION VII. MAINTENANCE PROCEDURES ............................................................................ 2-53
2-16. GENERAL.......................................................................................................................................................... 2-53
COMMON TASKS
2-17. INTERNAL DRINK TUBE ................................................................................................................................... 2-54
2-18. QUICK DISCONNECT COUPLING, EXTERNAL DRINKTUBE ........................................................................... 2-56
2-19. HEAD HARNESS............................................................................................................................................... 2-57
2-20. NOSECUP VALVE DISKS.................................................................................................................................. 2-58
2-21. AIRFLOW DEFLECTOR, INLET VALVE, AND VALVE BODY ............................................................................ 2-59
2-22. OUTLET VALVE COVER AND OUTLET VALVE DISK....................................................................................... 2-63
2-23. SIDE VOICEMITTER, VOICEMITTER RETAINER, AND GASKET ..................................................................... 2-65
2-24. INTERNAL DRINKTUBE NIPPLE....................................................................................................................... 2-66
2-25. OPTICAL INSERT KIT ....................................................................................................................................... 2-68
M40A1 PECULIAR TASKS
2-26. M40A1 FACEPIECE........................................................................................................................................... 2-73
M42A2 PECULIAR TASKS
2-27. M42A2 FACEPIECE........................................................................................................................................... 2-74
2-28. CLAMP COVER ................................................................................................................................................. 2-75
2-29. PORT GASKET.................................................................................................................................................. 2-76
SECTION VIII. CLEANING AND SANITIZING ............................................................................... 2-77
2-30. CLEANING M40A1............................................................................................................................................. 2-77
2-31. SANITIZING M40A............................................................................................................................................. 2-81
2-32. CLEANING M42A2............................................................................................................................................. 2-85
2-33. SANITIZING M42A2........................................................................................................................................... 2-91
SECTION IX. PREPARATION FOR STORAGE OR SHIPMENT................................................... 2-95
2-34. PREPARATION FOR STORAGE OR SHIPMENT .............................................................................................. 2-95
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TM 3-4240-346-20&P
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CHAPTER 2
UNIT MAINTENANCE INSTRUCTIONS
SECTION I. REPAIR PARTS, SPECIAL TOOLS, TMDE, AND SUPPORT
EQUIPMENT
2-1. COMMON TOOLS AND EQUIPMENT
" For authorized common tools and equipment, refer to the Modified Table of Organization and Equipment
(MTOE) applicable to your unit.
2-2. SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT
" Special tools, TMDE, and support equipment required are listed in Appendix C-Repair Parts and Special Tools
List (RPSTL) and Appendix B-Maintenance Allocation Chart (MAC).
2-3. REPAIR PARTS
" Repair parts are listed and illustrated in Appendix C of this manual.
SECTION II. SERVICE UPON RECEIPT
2-4. GENERAL
" This section contains instructions and procedures for services to be performed upon receipt of a new mask.
These services include unpacking and checking the mask.
2-5. SERVICE UPON RECEIPT OF MATERIAL
a. Table 2-1 contains instructions for performing the services required upon receipt of the M40A 1 mask.
b. Table 2-2 contains instructions for performing the services required upon receipt of the M42A2 mask.
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2-5 SERVICE UPON RECEIPT OF MATERIAL
Table 2-1. Service upon receipt -- M40A1 Mask
LOCATION ITEM ACTION REMARKS
WARNING
UNPACKING After removing the top of a wood
box, remove nails or bend nails to
1. OUTER BOX, Flaps (fiberboard box) or prevent injury.
FIBERBOARD OF top (wood box)
WOOD, AS NOTE
APPLICABLE If possible, retain shipping boxes
for possible future turn-ins.
Open box by cutting tape and
banding on fiberboard boxes or
remove top by cutting banding
and prying open top of wood
boxes. Remove nails or bend
nails over to prevent injury.
Remove inner fiberboard boxes.
Remove barrier bar around
facepiece folder.
NOTE
Second skin is packaged on top of
the facepiece in the facepiece/
second skin or universal second
skin assembly.
2. INNERFIBER- a. Facepiece/second skin Open inner box (1). Remove the
BOARDBOX assembly. facepiece/universal second skin
or second skin assembly (2). Take
the facepiece/universal second
skin or second skin assembly out
of the sealed bag and discard the
bag. Remove universal second
skin (3) or second skin (4).
NOTE
Masks stored more than 30 days
shall be stored with faceform in
facepiece. Keep all faceforms. Do
Not Discard.
Loosen head harness straps of
facepiece (5) and remove
clamshell (6) and faceform (7).
Cut tabs (8) where indicated.
Store at organization level.
Discard clamshell.
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Table 2-1. Service upon receipt -- M40A1 Mask
LOCATION ITEM ACTION REMARKS
UNPACKING (CONT) Remove protective polycovering
(9) from eyelenses (10) by pulling
covering away from eyelens to
stretch, then forward to remove.
Discard protective covering.
2.INNER FIBER- b. Fiberboard separator: Remove fiberboard separator
BOARD BOX (CONT) hood assembly, filter (11).
canister, outserts.
Take quick doff hood (12) out of
heat-sealed bag and discard bag.
Store unopened canisters (13)
until issued. Record lot number of
canister in accordance with unit
SOP.
Take clear (14) and neutral gray
(15) outserts out of heat-sealed
bags and discard bags.
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2-5 SERVICE UPON RECEIPT OF MATERIAL (CONT)
Table 2-1. Service upon receipt -- M40A1 Mask
LOCATION ITEM ACTION REMARKS
UNPACKING (CONT c. Poly-bag Mask Carrier Take improved field mask carrier
(16) out of bag and discard bag.
Take field mask carrier (17) out of
bag and discard bag.
d. Waterproof bag Remove waterproof bag (18) in
self-sealing plastic bag. Check
that three rubber bands (19) are
included.
e. Heat sealed bag-manual Take manual (20) out of heat-
sealed bag. Bag may be retained
to protect manual.
INSPECTION Inspect equipment for damage
incurred during shipment. If
equipment has been damaged,
report the damage on SF 364,
Report of Discrepancy (ROD).
Check equipment against packing
slip to see if shipment is complete.
Report all discrepancies in
accordance with the instructions
of DA PAM 738-750.
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Table 2-1. Service upon receipt -- M40A1 Mask
LOCATION ITEM ACTION REMARKS
PREPARINGTO STOW a. Universal second skin or Install universal second skin (3) or
THE MASK CARRIER second skin second skin (4) on facepiece (see
Operator's Manual).
b. Clear outserts Install clear Outserts (15) on
facepiece (see Operator's
Manual).
c. Mask Assembly Record alphanumeric number (21)
in a property book or log IAW unit
SOP.
d. Mask Assembly (22) Place faceform (7) into mask
(mask assembly, hood, assembly. Place neatly folded
head harness and quick doff hood ( 12) into back of
faceform). faceform. Tighten head harness to
hold quick doff hood.
e. Mask Assembly (23) Place faceform into mask
(mask assembly, head assembly. Tighten head harness
harness and faceform). (For to hold facefom
use with hooded
overgarments.) (USMC
only)
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2-5 SERVICE UPON RECEIPT OF MATERIAL (CONT)
Table 2-1. Service upon receipt -- M40A1 Mask
LOCATION ITEM ACTION REMARKS
STOWING IMPROVED a. Waterproof bag a. Install waterproof bag (18 )
FIELDMASK CARRIER inside left end pocket.'
b. Neutral gray outserts b. Install neutral gray outserts (14)
in left back pocket.
c. Operator's manual c. Pack operator's manual (20) in
the right back pocket.
d. Mask Assembly d. Store the mask assembly (22).
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Table 2-1. Service upon receipt -- M40A1 Mask
LOCATION ITEM ACTION REMARKS
STOWING a. Waterproof bag a Install waterproof bag (18 )
FIELDMASK inside left back pocket.
CARRIER
b. Neutral gray outserts b. Install neutral gray outserts (14)
in back middle pocket.
c. Operator's manual c. Pack operator's manual (20) in
the right back pocket.
d. Mask Assembly d. Store the mask assembly (22).
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2-5. SERVICE UPON RECEIPT OF MATERIAL (CONT)
Table 2-2. Service upon receipt -- M42A2 Mask
LOCATION ITEM ACTION REMARKS
UNPACKING WARNING
After removing the top of a wood
1. OUTERBOX, Flaps (fiberboard box) or box, remove nails or bend nails to
FIBERBOARD OR top (wood box) prevent injury.
WOOD, AS
APPLICABLE NOTE
If possible, retain some shipping
boxes for possible future turn-ins.
Open box by cutting tape and
banding on fiberboard boxes or
remove top by cutting banding
and prying open top of wood
boxes. Remove nails or bend
nails over to prevent injury.
Remove inner fiberboard boxes.
Remove barrier bar around
facepiece folder.
NOTE
Second skin, or universal second
skin is packaged on top of the
facepiece in the facepiece holder.
2. INNER FIBER- a. Facepiece fiberboard Take clear (1) and neutral gray (2)
BOARD BOX folder, outserts, and second outserts out of bags and discard
skin or universal second bags.
skin.
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Table 2-2. Service upon receipt -- M42A2 Mask
LOCATION ITEM ACTION REMARKS
UNPACKING (CONT)
NOTE
Masks stored more than 30 days
2. INNER FIBER- a. Facepiece fiberboard shall be stored with faceform in
BOARDBOX (CONT) folder, outserts, and second mask assembly. Keep all
skin, or universal second faceforms. Do Not Discard.
skin. (Cont)
Remove facepiece folder (3).
Remove facepiece (4) and
universal second skin (5), or
second skin (6) and discard both
folder and bag.
b. Facepiece and faceform. Loosen head harness straps of
facepiece (7) and remove
clamshell (8) and faceform (9).
Cut tabs (10) where indicated.
Store faceform at organization
level. Discard clamshell.
Remove protective poly-covering
(11) from eyelenses (12) by
pulling covering away from
eyelens to stretch, then forward to
remove. Discard protective
covering.
c. Mask Carrier
Take combat vehicle mask carrier
(13) out of bag and discard bag.
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2-5. SERVICE UPON RECEIPT OF MATERIAL (CONT)
Table 2-2. Service upon receipt -- M42A2 Mask (Cont)
LOCATION ITEM ACTION REMARKS
UNPACKING (CONT) d. Mask Carrier. Take field mask carrier (14) out of
bag and discard bag.
e. Quick doff hood Take quick doff hood (15) out of
(M42AI/M42A2). bag and discard bag.
f. Detachable microphone Take detachable microphone (16)
(M42A2). out of bag and discard bag.
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Table 2-2. Service upon receipt -- M42A2 Mask
LOCATION ITEM ACTION REMARKS
UNPACKING h. Canister Carrier Take canister carrier (17) out of
(CONT) bag and discard bag.
i. Vacuum sealed can Store unopened can (18) until is-
containing filter canister. Sued. Record lot number of filter
canister in accordance with unit
SOP.
j. Hose assembly Take hose assembly (19) out of
bag and discard bag.
k. Waterproof bag Remove waterproof bag (20) from
plastic bag and discard plastic
bag. Check that three rubber
bands (21) are included.
l. Heat sealed bag-manual Take manual (22) out of bag. Bag
may be retained to protect
manual.
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2-5. SERVICE UPON RECEIPT OF MATERIAL (CONT)
Table 2-2. Service upon receipt -- M42A2 Mask (Cont)
LOCATION ITEM ACTION REMARKS
INSPECTION Inspect equipment for damage
incurred during shipment. If
equipment has been damaged,
report the damage on SF 364,
Report of Discrepancy (ROD).
Check equipment against packing
slip to see if shipment is complete.
Report all discrepancies in
accordance with the instructions
of DA PAM 738-750.
PREPARING TO STOW a. Universal second skin or Install universal second skin (5)
THE MASK CARRIER second skin (see Operator's Manual) or
second skin (6) (see Operator's
Manual) on facepiece.
b. Clear outserts Install clear Outserts (1) on
facepiece (see Operator's
Manual).
c. Detachable Micro- Attach detachable microphone
phone (M42A2). (16) to front voicemitter opening of
facepiece (see Operator's
Manual).
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Table 2-2. Service upon receipt -- M42A2 Mask
LOCATION ITEM ACTION REMARKS
d. Mask assembly Record 13 digit alphanumeric
PREPARING TO STOW number (23) in a property book or
THE MASK CARRIER log IAW unit SOP.
(CONT)
e. Hose Assembly Attach the hose assembly (19) to
the mask assembly (4) (see
Operator's Manual).
f. Mask assembly (24) Place faceform (9) into mask
(mask assembly, hood, assembly. Place neatly folded
head harness and face- quick doffhood (15) (M42A1/
form). M42A2) into back of faceform.
Tighten head harness to hold
quick doff hood.
g. Mask assembly (25) Place faceform into mask
(mask assembly, hood, assembly. Tighten head harness
head harness and face- to hold faceform.
form). (For use with hooded
overgarments.)
(USMC only)
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2-5. SERVICE UPON RECEIPT OF MATERIAL (CONT)
Table 2-2. Service upon receipt -- M42A2 Mask (Cont)
LOCATION ITEM ACTION REMARKS
STOWING THE
COMBAT VEHICLE a. Waterproof bag Store waterproof bag (20) in right
MASK CARRIER pocket.
b. Neutral gray outserts Store neutral gray outserts (2) in
left pocket.
c. Manual Store operator's manual (22) in
the middle pocket.
d. Canister Carrier Store the canister carrier (17).
e. Mask Assembly Store the mask assembly (24).
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Table 2-2. Service upon receipt -- M42A2 Mask
LOCATION ITEM ACTION REMARKS
STOWING THE FIELD
MASK CARRIER
a. Waterproof bag Store waterproof bag (20) in
inside left end pocket.
b. Neutral gray outserts Store neutral gray outserts (2) in
left back pocket.
c. Manual Store operator's manual (22) in
the right back pocket.
d. Canister Carrier Store the canister carrier (17).
e. Mask Assembly Store the mask assembly (24).
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2-6. IDENTIFYING AN INDIVIDUAL' S MASK
Although a mask will be used only by the soldier to whom it is issued and fitted, do not make permanent identification
marking on either mask or mask carrier (AR 700-84). A card may be placed in the exterior side pocket with the soldier's
name or a code number for identification purposes. The date the mask was tested and fitted to the soldier along with the ID
code will be recorded in accordance with local SOP. Include the lot number of the canister and the mask assembly.
Each unit will devise its own code to ensure operational security. Take care not to include any designations that may identify
the parent organization.
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SECTION III. EQUIPMENT/USER FITTING INSTRUCTIONS
2-7. ADJUSTING MASK ASSEMBLY AT INITIAL FITTING
THIS TASK COVERS: a. Putting on mask assembly b. Adjusting mask assembly c. Checking mask assembly for fit
INITIAL SETUP:
Personnel Required:
NBC NCO or other trained person
Soldier to be fitted
Applicable Configurations:
M40A1/M42A2
Materials/Parts:
M41 Protection Assessment Test System (If Available)
OR
n-Amyl acetate (banana oil) (item 11, app D)
OR
Stannic Chloride (tube smoke) (item 16, app D)
References:
TC 3-41
WARNING
Before putting on and adjusting mask assembly, soldiers shall
remove all hairpins, combs, hair knots, buns, or braids that will
interfere with mask assembly seal. Soldiers must be clean
shaven to prevent mask assembly leaks.
DO NOT wear contact lenses (soft or hard) while wearing CB
Protective Masks. Inadequate oxygen supply to the corneal
surface, exposure to dust, dirt, and smoke/ gas may cause
serious vision loss or eye damage. Soldiers requiring vision
correction are provided optical inserts for their protective masks.
NOTE
Initial mask assembly fitting should be performed by the unit NBC NCO or other trained person.
There is no special tool for sizing with the M40A1/M42A2 masks. You will have to use your
judgement and the guidelines found in this paragraph on size selection. Initial fitting is done
without the hood installed.
The protective mask fit may be checked by the following equipment/tests. The order of preference
for mask fitting and testing is the M41 Protection Assessment Test System (PATS) if available, n-
Amyl acetate (banana oil), or stannic chloride (tube smoke).
Detailed instructions for checking the fit with the M41 PATS is found in the M41 operator's
manual and in TC 3-41. Detailed instructions for checking the fit with banana oil is in para 2-8 of
this manual.
After initial fitting of soldier's mask, determine if soldier fires from right or left. Convert mask
accordingly (para 2-13). Determine if soldier requires vision correction and install as required
(para 2-25).
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2-7. ADJUSTING MASK ASSEMBLY AT INITIAL FITTING (CONT)
a. PUTTING ON MASK ASSEMBLY
WARNING
Edges of open can are sharp.
1. Use attached key (1) to open canister can (2) and remove filter canister (3).
NOTE
Optical inserts should be installed, if required.
2. Install filter canister on mask assembly (4) (M40A1 only).
3. Feed hose end connector (5) through canister carrier (6) (M42A2 only).
4. Install filter canister on hose connector and secure canister carrier cover (7) (M42A2 only).
5. Loosen head harness (8) so that strap ends are approximately 1 in. (2.5 cm) from buckles.
6. Pull head harness over front of mask assembly (9).
7. Hold hair back from sealing area and place chin in the chin pocket (10).
8. Have soldier slip head harness over head while holding mask assembly against face.
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b. ADJUSTING MASK ASSEMBLY
1. Have soldier hold mask assembly (9) tightly against chin.
2 (NBC NCO) Center head harness pad (11) on back of soldier's head and have soldier hold in place.
3. (NBC NCO) Place finger or thumb under buckle (12) of forehead strap (13). Then give strap end short, sharp tugs
until buckle feels snug. Adjust other forehead strap in same manner.
4. (NBC NCO) Place finger or thumb under buckle (14) of cheek strap (15) and adjust cheek strap until it feels snug.
Adjust other cheek strap in same way.
5. Have soldier release mask assembly. Mask assembly should not slip down. If mask assembly slips, readjust
forehead straps and cheek straps until mask assembly remains in place.
6. (NBC NCO) Place finger or thumb under buckle (16) of temple strap (17) and adjust temple strap until buckle feels
snug against finger. Repeat adjustment on other temple strap.
CAUTION
Improperly adjusted internal drink tube may irritate lips if it
touches them while wearing mask assembly.
7. Ask if internal drink tube touches soldier's lips. Adjust length of internal drink tube if necessary (para 2-17).
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2-7. ADJUSTING MASK ASSEMBLY AT INITIAL FITTING (CONT)
c. CHECKING MASK ASSEMBLY FOR FIT
WARNING
Soldier's safety depends on proper fitting mask assembly.
NOTE
When doffing mask, only loosen the cheek straps.
1. Edge of mask assembly (9) comes up on forehead but not into hairline and within 1 in. (2.5 cm) of ear.
2 Temple straps (17) and cheek straps (15) do not cut into ears.
3. Soldier's pupils are within the center one-third area (vertical) (18) of the eyelens (19). Adjust optical inserts if
required (para 2-25).
4. Mask assembly does not press flesh so tightly that eyes are partly closed.
5. Bottom of mask assembly does not cut into throat.
6. Skin in front of ear is not wrinkled.
7. Nosecup (20) does not obscure vision.
8 If mask assembly still does not meet above standards, try another size mask.
NOTE
FOLLOW-ON MAINTENANCE: Check the mask assembly for Proper Function. (para 2-8).
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2-8. CHECKING MASK ASSEMBLY FOR PROPER FUNCTION
THIS TASK COVERS: a. Testing mask assembly with M41 PATS
b. Testing mask assembly with n-Amyl acetate
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
Personnel Required:
NBC NCO or other trained person
Soldier to be tested
Materials/Parts:
M41 PATS
Applicator (item 1, app D)
n-Amyl acetate (banana oil) (item 11, app D)
Rubber gloves (item 8, app D)
References:
TM 3-4240-346- 10/TM09204A/09205A-10/1.
TC 3-41
Commercial Manual (M41)
NOTE
PMCS should be conducted and verified prior to proper function testing.
The order of preference for mask fitting and testing is the M41 Protection Assessment Test
system (PATS) if available, n-Amyl acetate (banana oil), or stannic chloride (tube smoke).
COMMON
a. TESTING MASK ASSEMBLY WITH M41 PATS
1. Have soldier put on and adjust mask assembly (para 2-7).
2. Refer to TC 3-41 and Commercial Manual for instructions on the use of the M41 PATS.
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2-8. CHECKING MASK ASSEMBLY FOR PROPER FUNCTION (CONT)
COMMON (CONT)
b. TESTING MASK ASSEMBLY WITH N-AMYL ACETATE
WARNING
N-amyl acetate is flammable. DO NOT touch skin (or the soldier)
with n-Amyl acetate. It could irritate the skin. Wear rubber
gloves. DO NOT smoke around n-Amyl acetate. Keep n-Amyl
acetate away from an open flame. DO test mask assembly in a
well-ventilated room. N-Amyl acetate may be toxic if inhaled in
quantity.
NOTE
Soldier should breathe deeply through nose only. If soldier smells n-Amyl acetate just before
masking, test results will be inaccurate.
1. Dip applicator in n-Amyl acetate (banana oil).
2. Move applicator approximately 1 to 2 in. (2.5 or 5.1 cm) from mask assembly as follows:
a. Have soldier turn head to left and move applicator completely around outer edge of mask assembly.
b. Have soldier turn head to the right, again move applicator around outer edge of mask assembly.
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c. Have soldier tilt head upward and turn head from side to side, move applicator under chin around outer edge of
mask assembly.
d. Have soldier tilt head forward, move applicator around outer edge of mask assembly.
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2-8. CHECKING MASK ASSEMBLY FOR PROPER FUNCTION (CONT)
b. TESTING MASK ASSEMBLY WITH N-AMYL ACETATE (CONT)
M40A1 PECULIAR
e. Have soldier smile and frown while looking straight ahead. Move applicator around both eyelenses (1), front
voicemitter (2), side voicemitter (3), filter canister (4) and outlet valve cover (5).
f. Instruct soldier to press palms firmly over filter canister, but not so firmly that mask assembly is distorted and
loses its seal. Have soldier breathe in, creating a vacuum and collapsing mask assembly. Move applicator
around outer edge of mask assembly before having soldier breathe out.
M42A2 PECULIAR
g. Have soldier smile and frown while looking straight ahead. Move applicator around both eyelenses (1), front
voicemitter (2), side voicemitter (3), star knob (6), and outlet valve cover (5).
h. To test seal integrity for the connector at each end of the hose assembly, check the clamp cover (7) on each
end of the hose (8).
i. Move applicator around the canister carrier (9).
j. Instruct soldier to press palm firmly over Armor Quick Disconnect Opening (10). Have soldier breathe in,
creating a vacuum and collapsing mask assembly. Move applicator around outer edge of mask assembly before
having soldier breathe out.
2-26
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
NOTE
If soldier being tested smells n-Amyl acetate (banana oil) during initial fitting and testing,
a 5-7 minute odor sensitivity recovery period is required before retesting.
4. If soldier can smell n-Amyl acetate, readjust head harness to improve fit (para 2-7) and repeat above check.
5. If soldier cannot smell n-Amyl acetate, have him unmask and smell the applicator to be sure that his sense of smell
is not impaired. If soldier's sense of smell is impaired, the mask assembly must be tested in a CS (irritant) chamber
or using a smoke tube (item 16, app D) and an aspirator bulb (item 4, app D) containing stannic chloride, which
produces an irritating acid smoke. The smoke tube test should be conducted in still air in an area that can be
ventilated.
NOTE
FOLLOW-ON MAINTENANCE: Remove mask assembly and stow in carrier in accordance
with TM 3-4240-346-10/TM 09204A/09205A-10.
2-27
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-9. CHECKING DRINKING SYSTEM FOR PROPER FUNCTION
THIS TASK COVERS: Testing Drinking System
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
Personnel Required:
NBC NCO or other trained person
Soldier (mask wearer)
TESTING DRINKING SYSTEM
a. Steady mask assembly (1), withdraw quick disconnect coupling half (2) from retainer (3) and let it hang freely.
b. Grasp internal drink tube (4) between your lips.
WARNING
If resistance is not felt when checking drinking system, the drinking system leaks.
c. Blow into internal drink tube. If resistance is not felt, drink system is leaking.
d. A more positive test may be done on the external drink tube quick disconnect by the following procedure:
(1) Fill cup (5) full of water.
(2) Place mask assembly on face.
(3) Dip quick disconnect in cup filled with water.
(4) Blow into internal drink tube.
(5) Watch for bubbles in water. If no bubbles, quick disconnect is operational. If bubbles are detected, the
quick disconnect is not operational. (Refer to para 2-18).
2-28
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
SECTION IV. TROUBLESHOOTING
2-10. TROUBLESHOOTING PROCEDURES
a. Perform functional test first. Then use the symptom index for quick access to the troubleshooting procedures.
b. The following describes the use of the troubleshooting procedures.
SYMPTOM INDEX PAGE
COMMON
1. Eyelens Fog Excessively..................................................................................................................... 2-30
M140A1 PECULIAR
2. Insufficient Air to User ......................................................................................................................... 2-31
3. Mask Assembly Fails To Seal.............................................................................................................. 2-32
M42A2 PECULIAR
4. Insufficient Air to User ......................................................................................................................... 2-35
5. Mask Assembly Fails To Seal.............................................................................................................. 2-36
2-29
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-10. TROUBLESHOOTING PROCEDURES - (CONT)
COMMON
2-30
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
M40A1 PECULIAR
2-31
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-10. TROUBLESHOOTING PROCEDURES - (CONT)
M40A1 PECULIAR (CONT)
2-32
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-33
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/
2-10. TROUBLESHOOTING PROCEDURES - (CONT)
M40A1 PECULIAR (CONT)
2-34
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
M42A2 PECULIAR
2-35
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-10. TROUBLESHOOTING PROCEDURES - (CONT)
M42A2 PECULIAR (CONT)
2-36
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-37
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-10. TROUBLESHOOTING PROCEDURES - (CONT)
M42A2 PECULIAR (CONT)
2-38
TM 34240-346-20&P
TM 09204A/09205A - 20&P/2
SECTION V. PREVENTIVE MAINTENANCE CHECKS AND SERVICES
(PMCS)
2-11. INTRODUCTION TO PMCS TABLE
a. General. Unit PMCS is performed semiannually (every 6 months). The soldier may perform semiannual PMCS
under supervision of NBC NCO or other trained person. Unit PMCS is performed to assure that the more
experienced NBC NCO regularly checks that the soldier is properly doing daily PMCS. This allows the NBC
NCO to perform his responsibilities to assure that: 1. The soldiers are properly performing their daily PMCS; 2.
The soldiers are properly performing their monthly PMCS; and 3. That the soldiers are involved in performing
the semiannual PMCS. In addition the NBC NCO is responsible for assuring that those checks identified are
performed on a weekly basis during combat situations. Semiannual PMCS and initial and mandatory fit
validation M41 test will be scheduled and will be recorded on DD Form 314, Preventive Maintenance Schedule
and Record. The Semiannual PMCS will be completely performed in accordance with the applicable operator's
manual (TM 3-4240-346-10/TM 09204A/09205A-10) and this TM. Marine Corps Users will perform and record
semiannual maintenance in accordance with procedures prescribed in TM 4700-15/1_ and unit SOP.
b. Inspections. The most detailed inspections and PMCS of the mask is performed when it is first received, after
each use, semiannually and during the annual fit test. The NBC NCO is involved in all of these inspections. This
allows the NBC NCO to assure that the operator is properly doing the daily PMCS.
c. WARNINGS and CAUTIONS. It is vital to the safety of the operator and the Unit Maintenance personnel that all
WARNINGS and CAUTIONS are followed. It is also the responsibility of the NBC NCO to make sure the
operator understands their importance and follows them very carefully.
d. Training Materials. Training materials are available (see Appendix A).
NOTE
Conduct an initial and annual fit test of all assigned masks using the Protection
Assessment Test System (PATS M41), if available, banana oil, or stannic chloride.
2-12. PMCS PROCEDURES
The following paragraphs describe the information presented in each column of the PMCS table.
a. Item Number Column. Numbers in this column are for reference. When completing DA Form 2404 (Equipment
Inspection and Maintenance Worksheet), include the item number for the check/service indication at fault. Item
numbers also appear in the order that you must do checks and services for the intervals listed. Record any
faults that you discover before, during, or after operation. You DO NOT need to record faults that you fix.
b. Interval. This column of your PMCS table tells you when to do a certain check or service.
c. Item to be Inspected Column. This column identifies the item to be checked or serviced.
d. Procedure Column. This column briefly describes this procedure for performing the check or service. Whenever
replacement or repair is recommended, reference is made to para number for the applicable maintenance
Instruction.
e. Not Fully Mission Capable If: Column. Information in this column only tells you what deficiencies will keep your
equipment from being capable of performing its primary mission safely. DO NOT use your mask if a check and
service shows a fault listed in this column. Shortcomings or minor discrepancies which DO NOT limit operational
capability or safety of use may require corrective surveillance, but does not "deadline" the mask.
f. Other Table Entries. Be sure to observe all special information and notes that appear in your table.
NOTE
All PMCS tasks are common to both the M40A1 and the M42A2. Therefore, all PMCS
tasks must be performed regardless of which mask you have. Please note that all tasks
are illustrated with the M42A2 mask, however, the procedures indicated are common.
2-39
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-12. PMCS PROCEDURES (CONT)
Table 2-3. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES
ITEM INTERVAL ITEM TO BE PROCEDURE NOT FULLY
NO. CHECKED OR MISSION
SERVICED CAPABLE IF:
COMMON
CAUTION
DO NOT use a high pressure hose to
clean mask. It may damage
components.
NOTE
Sanitizing will be done prior to reissue
to another soldier or prior to turn-in as
excess.
Make sure finish covers all metal
surfaces. Coat all bare metal surfaces
with lacquer (item 10, APP D).
1 Semiannual Mask Assembly
Schedule
(PMCS)*
Mask Assembly Mask
a. Check mask assembly (1) for dirt or
assembly is dirty enough
permanent set which may affect fit or
to affect mask assembly
conformance to the face. Signs of
seal or function.
permanent set are:
Mask assembly has a
1. Mask assembly is difficult to
permanent set, or
spread open.
stiffness.
2. Unusual stiffness in sealing area
of mask assembly.
Eyelens will pull away
b. Check rubber next to eyelens (2) to
from mask assembly.
be sure neither eyelens will pull away
from mask assembly.
2-40
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-12. PMCS PROCEDURES
Table 2-3. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES
ITEM INTERVAL ITEM TO BE PROCEDURE NOT FULLY
NO. CHECKED OR MISSION
SERVICED CAPABLE IF:
c. Pull head harness (3) over front of The black silicon has any
mask. cuts or tears.
Pull chin flap (4) forward so you can
see under it. Look around the two
holes (5) in the chin cup (6) for cuts
or tears.
d. Hold nosecup chin flap (4) back so
you can see the internal drink tube
connection (7).
e. Check the internal drink tube Internal drink tube nipple
connection, inside the mask is broken and cannot be
assembly to see if it is broken. If the replaced.
connection looks like the left
illustration, replace the facepiece
(para 2-26, M40A1; para 2-27,
M42A2). If the connection looks like
the right illustration, replace the
internal drink tube nipple
(para 2-25).
2-41
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-12. PMCS PROCEDURES (CONT)
Table 2-3. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (CONT)
ITEM INTERVAL ITEM TO BE PROCEDURE NOT FULLY
NO. CHECKED OR MISSION
SERVICED CAPABLE IF:
COMMON
1 Semiannual Mask Assembly (Cont)
Schedule
(PMCS)*
f. Place thumb on sideport (8) and
fingers inside mask (1). Push up
gently with thumb while pulling
gently with fingers until mask snaps
up to reveal inside of mask area (9)
around sideport.
g. Fold back nosecup (10) so view of
Mask has any holes, cuts
area around sideport is clear.
or tears.
Inspect area around sideport for
holes, cuts or tears. For
replacement see para 2-26, M40A1
or para 2-27, M42A2.
2-42
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-12. PMCS PROCEDURES
Table 2-3. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES
ITEM INTERVAL ITEM TO BE PROCEDURE NOT FULLY
NO. CHECKED OR MISSION
SERVICED CAPABLE IF:
WARNING
Do nut push up hard on side voicemitter
retainer. The retainer could cut the
facepiece and cause leaks.
h. Place thumb on side voicemitter
(11) and fingers inside mask (1).
Push up gently with thumb while
pulling gently with fingers until mask
snaps up to reveal inside of mask
area (12) around side voicemitter.
i. Fold back nosecup ( 10) so view of
area around side voicemitter is
clear. Inspect area around sideport
for holes, cuts or tears. For
Mask has any holes, cuts
replacement see para 2-26, M40A1
or tears.
or para 2-27, M42A2.
2-43
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-12. PMCS PROCEDURES (CONT)
Table 2-3. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (CONT)
ITEM INTERVAL ITEM TO BE PROCEDURE NOT FULLY
NO. CHECKED OR MISSION
SERVICED CAPABLE IF:
COMMON
2 Semiannual Front voicemitter
Schedule
(PMCS)*
Front Voicemitter is
a. Check Front Voicemitter (13 ) for
cracked, damaged or
damage, cracks or distortion that
distorted.
may affect voice transmission.
3 Side voicemitter Side voicemitter retainer
a. Remove side voicemitter retainer
has cracks or distortion.
(14) by unscrewing counter
clockwise with the D-ring (15) on
the carrier. Inspect retainer for
cracks or distortion. For
replacement see para 2-23.
Side voicemitter retainer
b. Remove side voicemitter (16) and
has cracks or distortion.
inspect for holes, cracks, or
warping. For replacement see
para 2-23.
Gasket is split, sticky or
c. Remove gasket (17) and check for
compressed.
splits, sticky, or compressed areas.
For replacement see para 2-23.
2-44
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
SECTION VI. CONVERSION PROCEDURES
2-13. LEFT/RIGHT FILTER CANISTER/HOSE ASSEMBLY CONVERSION
THIS TASK COVERS: Conversion Instructions
INITAL SETUP:
Applicable Configurations:
M40A1/M42A2
Equipment condition:
Quick Doff Hood removed. (See Operator's Manual)
CONVERSION INSTRUCTIONS
1. Remove filter canister (I) by turning counterclockwise (M40A1 only).
2. Remove hose (2) by turning the star knob (3) counterclockwise (M42A2 only).
CAUTION
Be careful when disconnecting buttons. The mask assembly may
be damaged if care is not exercised.
3. Disconnect the airflow deflector (4) from mask assembly (5) by carefully pulling the silicon rubber housing (6) away
from the airflow deflector buttons (7).
2-45
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-13. LEFT/RIGHT HOSE ASSEMBLY CONVERSION (CONT)
4. Grasp a tab (8) on inlet valve body (9) and pull toward center of inlet valve body until unsealed from sideport (10).
5. Tuck unseated portion of inlet valve body into the mask assembly. Remove airflow deflector from mask assembly.
6. Remove side voicemitter retainer (11) by unscrewing counterclockwise using the D-ring (12) on the mask carrier.
2-46
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
7. Remove side voicemitter (13) from mask assembly by pressing from inside of mask assembly (5). Remove gasket
(14) from sideport (10) housing on mask exterior.
WARNING
Be sure the inlet valve body is installed on the post of the airflow
deflector with the tabs of the inlet valve body away from the inlet
valve disk. If it is installed improperly, the mask will leak.
8. Check that inlet valve body (9) is installed on the post of the airflow deflector with the tabs (8) of the inlet valve body
away from the airflow deflector (4).
9. Position airflow deflector in pocket on opposite side of mask assembly.
2-47
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-13. LEFT/RIGHT HOSE ASSEMBLY CONVERSION (CONT)
CAUTION
DO NOT pull on spokes of valve body while installing. This will break the spokes
and require replacement of the valve body.
10. With one hand push inlet valve body (9) through sideport (10). With other hand pull on thick outer rim (15) of valve
body until valve body is completely through sideport.
11. Push buttons (7) on sides of airflow deflector (4) into button holes (16) in mask assembly pocket.
12. Press lightly around thick outer rim of valve body until the valve body seats in the sideport.
2-48
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
13. Install filter canister (1) by turning clockwise.
14. Install hose (2) by turning star knob (3) clockwise.
WARNING
Be sure the side voicemitter is installed with the flange and four
beads facing out. If installed incorrectly it could cause the mask
assembly to leak.
15. Position gasket (14) in sideport (10).
16. Install side voicemitter (13) with four beads (17) facing out..
17. Position side voicemitter retainer (I 1) in sideport.
2-49
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-13. LEFF/RIGHT HOSE ASSEMBLY CONVERSION (CONT)
18. Tighten voicemitter retainer (11) by turning clockwise with the D-ring (12) on the mask carrier strap.
19. Check for proper function (para 2-8).
2-50
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-14. M40A1 TO M42A2 CONVERSION
THIS TASK COVERS: Conversion Instructions
INITIAL SETUP:
Applicable Configurations:
M40A1
Equipment condition:
Quick Doff Hood removed. (See Operator's Manual)
Materials/Parts:
Detachable Microphone
Hose Assembly
Canister Carrier
Combat Vehicle Mask Carrier
CONVERSION INSTRUCTIONS
1. Remove filter canister (1) (see Operator's Manual).
2. Install hose assembly (2) (see Operator's Manual).
3. Install filter canister in canister carrier (3) (see Operator's Manual).
4. Install detachable microphone (4) (see Operator's Manual).
5. Stow mask in combat vehicle mask carrier and turn in field mask carrier.
2-51
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-15. M42A2 TO M40A1 CONVERSION
THIS TASK COVERS: Conversion Instructions
INTIALSETUP:
Applicable Configurations:
M42A2
Equipment condition:
Quick Doff Hood removed. (See Operator's Manual)
Materials/Parts:
Field Mask Carrier
CONVERSION INSTRUCTIONS
1. Remove hose assembly (1) (see Operator's Manual).
2. Remove filter canister (2) from canister carrier (3) (see Operator's Manual).
3. Remove detachable microphone (4) (see Operator's Manual).
4. Install filter canister by turning clockwise (see Operator's Manual).
5. Stow mask in field mask carrier and turn in combat vehicle mask carrier, detachable microphone, and canister
carrier.
2-52
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
SECTION VII. MAINTENANCE PROCEDURES
2-16. GENERAL
a. The maintenance procedures in this section are to be performed by a unit NBC NCO or by the user under unit
NBC NCO supervision.
b. This section is divided into those tasks which are common to the M40A1 and the M42A2, those tasks which
are peculiar to the M40A 1, and those tasks which are peculiar to the M42A2. Common tasks are illustrated
with the M42A2.
c. This section contains detailed instructions for replacing the following components.
Para. Page
COMMON TASKS
2-17. INTERNAL DRINKTUBE .......................................................................................................................................2-54
2-18. QUICK DISCONNECT COUPLING, EXTERNAL DRINK TUBE .............................................................................2-56
2-19. HEAD HARNESS..................................................................................................................................................2-57
2-20. NOSECUP VALVE DISKS.....................................................................................................................................2-58
2-21. AIRFLOW DEFLECOR, INLET VALVE, AND VALVE BODY..................................................................................2-59
2-22. OUTLET VALVE COVERAND OUTLET VALVE DISK...........................................................................................2-63
2-23. SIDE VOICEMITTER, VOICEMlTTER RETAINER, AND GASKET ........................................................................2-65
2-24. INTERNAL DRINK TUBE NIPPLE........................................................................................................................2-66
2-25. OPTICAL INSERT KIT ..........................................................................................................................................2-68
M40A1 PECULIAR TASKS
2-26. M40A1 FACEPIECE..............................................................................................................................................2-73
M42A2 PECULIAR TASKS
2-27. M42A2 FACEPIECE..............................................................................................................................................2-74
2-28. CLAMP COVER ....................................................................................................................................................2-75
2-29. PORT GASKET.....................................................................................................................................................2-76
2-53
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
COMMON
2-17. INTERNAL DRINK TUBE
THIS TASK COVERS: a. Removal b. Installation c. Checking for Fit
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
Materials/Parts:
Shears (item 14, app D)
a.REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
NOTE
There are two types of internal drink tubes. The original drink
tube and a revised drink tube which is used only when the drink
tube nipple has been replaced. Both are illustrated.
1. Lay mask assembly (1) face down on nonabrasive surface.
2. Grasp internal drink tube (2) at drink tube coupling (3) and pull internal drink tube away from coupling.
b.INSTALLATION
1. Lay mask assembly face down on nonabrasive surface.
2. Install internal drink tube on drink tube coupling and press internal drink tube until it bottoms fully against drink tube
coupling.
2-54
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
c.CHECKING FOR FIT
CAUTION
Internal drink tube will irritate lips if it touches them while wearing mask
assembly.
Internal drink tube must be removed from mask assembly prior to adjusting
length to prevent damage to mask assembly.
NOTE
Slight pressure on the top of the outlet valve body should
enable the internal drink tube to be grasped by the soldier's
lips.
1. Have soldier put on mask assembly and check to see if internal drink tube touches lips.
2. If internal drink tube (2) touches soldier's lips while wearing mask assembly (1), adjust length of internal drink tube
as follows:
a. Remove internal drink tube from mask assembly.
b. Cut internal drink tube behind first barb (4).
c. Install internal drink tube.
CAUTION
DO NOT remove the last barb, as this is needed for proper function.
3. Repeat steps 1 and 2, if necessary, to achieve proper fit.
2-55
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
COMMON (CONT)
2-18. QUICK DISCONNECT COUPLING, EXTERNAL DRINK TUBE
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
a. REMOVAL
1. Lay mask assembly (1) face up.
2. Remove quick disconnect coupling (2) from retainer (3).
3. Grasp external drink tube (4) where it joins the quick disconnect coupling , with one hand, and with the other, grasp
the quick disconnect coupling and pull away with a twisting motion, disengaging the external drink tube from the
quick disconnect coupling.
b.INSTALLATION
NOTE
Quick disconnect tube connection may be moistened with water
to aid in coupling it with the rubber tubing.
1. Lay mask assembly face up.
2. Insert quick disconnect coupling into the external drink tube and, with a twisting motion, press drink tube in place.
Ensure tube extends over the nipple end of the quick disconnect by 5/8 - 3/4 inch.
3. Verify drink system for leaks in accordance with para 2-9.
4. Reinstall quick disconnect coupling in retainer.
5. Check for leaks in accordance with para 2-9.
2-56
TM 3-4240-346-20&P
TM 09204A/09205A 20&P/2
2-19. HEAD HARNESS
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
" Work head harness straps (1) out of buckles (2).
b. INSTALLATION
NOTE
Elastic webbing that joins the two forehead straps must be on
outside to avoid hot spots on head.
1. Position head harness (3) in mask assembly (4) with head harness straps next to buckles and tab (5) down.
2. Work head harness straps into buckles and pull through approximately 1 in. (2.5 cm) so that head harness strap
ends are outside.
3. Stretch head harness away from mask assembly and check that buckles hold head harness straps tightly.
4. Perform Initial Fitting Procedures. (para 2-7)
2-57
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/
COMMON (CONT)
2-20. NOSECUP VALVE DISKS
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
To avoid tears, do not stretch rubber more than necessary to remove or install
parts.
1. Pull head harness (1) over front of mask assembly (2).
2. Curl back lip of nosecup (3) to expose nosecup valve seat (4) and valve disk (5).
3. Pull nosecup valve disk out of each nosecup valve seat from inside of nosecup.
b. INSTALLATION
NOTE
It may be necessary to pull on nosecup valve disk stem from
outside of nosecup while pressing it into the nosecup valve seat
from inside of nosecup.
Moisten the stem of nosecup valve disks with water to aid in
installation.
1. Press nosecup valve disk into nosecup valve seat from inside of nosecup until nosecup valve disk is flat against
nosecup valve seat and the stem (6) slips completely through the hole (7) in the nosecup valve body.
2. Gently rotate nosecup valve disk to make sure it is completely seated.
3. Repeat steps 1. and 2. to install remaining nosecup valve disk.
4. Return head harness to its original position.
2-58
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-21. AIRFLOW DEFLECTOR, INLET VALVE, AND VALVE BODY
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
Equipment Condition:
Hose removed (M40A1/M42A2)
Canister carrier removed (M40A1/M42A2)
Quick Doff Hood Removed (M40A1/M42A2)
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
Be careful when disconnecting buttons. The mask assembly may be damaged if
care is not exercised.
1. Disconnect the airflow deflector (1) from mask assembly (2) by carefully pulling the silicon rubber housing away
from the airflow deflector buttons (3).
2. Grasp a tab (4) on inlet valve body (5) and pull toward center of inlet valve body until unseated from sideport (6).
2-59
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
COMMON (CONT)
2-21. AIRFLOW DEFLECTOR, INLET VALVE, AND INLET VALVE BODY (Cont)
a. REMOVAL (Cont)
3. Tuck unseated portion of inlet valve body (5) into the mask assembly. Remove airflow deflector (1) from mask
assembly (2).
4. Grasp inlet valve body with thumb under two spokes (7). Pull and peel off airflow deflector post (8).
5. Pull inlet valve disk (9) from airflow deflector post.
2-60
TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
b. INSTALLATION
WARNING
Be sure the inlet valve body is installed on the post of the airflow
deflector with the tabs of the inlet valve body away from the inlet
valve disk. If it is install improperly, the mask will leak.
NOTE
There are two sizes of deflectors. Ensure that the deflector size
matches the mask size.
1. Position inlet valve disk (9) on lower groove (10) of airflow deflector post (8).
2. Position the inlet valve body (5) on the airflow deflector post. Be sure that the tabs (4) of the inlet valve body face
away from the inlet valve disk.
3. Position airflow deflector (1) in pocket on side of mask assembly.
CAUTION
DO NOT pull on spokes of inlet valve body while installing. This will break the
spokes and require replacement of the inlet valve body.
4. With one hand push inlet valve body through sideport (6). With other hand pull on thick outer rim (11) of inlet valve
body until inlet valve body is completely through sideport.
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COMMON (CONT)
2-21. AIRFLOW DEFLECTOR, INLET VALVE, AND INLET VALVE BODY (Cont)
b. INSTALLATION (Cont)
5. Push buttons (3) on sides of airflow deflector (1) into button holes (12) in mask assembly pocket.
6. Press lightly around thick outer rim (11) of inlet valve body (5) until the inlet valve body seats in the sideport
housing.
7. Check for Proper Function (para 2-8).
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TM 3-4240-346-20&P
TM 09204A/09205A - 20&P/2
2-22. OUTLET VALVE COVER AND OUTLET VALVE DISK
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
Do not damage cover when removing outlet valve cover.
1. Pull quick disconnect coupling (1) out of retainer (2) on outlet valve cover (3).
2. Pull up on drink tube retainer (4) on bottom of outlet valve cover until outlet valve cover is disengaged from outlet
valve body (5).
3. Remove outlet valve cover from flanges (6) on top of outlet valve body.
4. Pull outlet valve disk (7) out of outlet valve body and discard.
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TM 09204A/09205A - 20&P/2
COMMON (CONT)
2-22. OUTLET VALVE COVER AND OUTLET VALVE DISK (CONT)
b. INSTALLATION
CAUTION
Do not use any tools or instruments to install outlet valve disk. Damage to valve seat may
occur which would cause leakage.
NOTE
Moisten stem of outlet valve disk with water to aid installing
outlet valve disk into outlet valve body.
1. Start stem (8) of outlet valve disk (7) through hole (9) in middle of outlet valve body (5).
2. Press outlet valve disk in while pulling on the inside stem of the outlet valve disk until shoulder of stem slips through
hole in outlet valve body.
3. Check that outlet valve disk lies flat and smooth and has continuous contact with outlet valve seat
4. Rotate outlet valve disk with finger to make sure it is properly seated.
5. Install outlet valve cover (3) on flanges (6) on top of outlet valve body.
6. Using drink tube retainer (4) on bottom of outlet valve cover, pull outlet valve cover over face of outlet valve body.
Made sure outlet valve cover snaps in place around outlet valve body.
7. Install quick disconnect coupling (1) securely in retainer (2). Fasten external drink tube (10) to drink tube retainer.
8. Check for Proper Function (para 2-8).
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TM 09204A/09205A - 20&P/2
2-23. SIDE VOICEMITTER, VOICEMITTER RETAINER, AND GASKET
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
1. Remove side voicemitter retainer (1) by unscrewing counterclockwise using the D-ring (2) on the mask carrier strap.
2. Remove the side voicemitter (3) and gasket (4) by pushing from inside of mask out of the side port (5).
b. INSTALLATION
WARNING
Be sure the side voicemitter is installed with the flange and four
beads facing out. If installed incorrectly it could cause the mask
assembly to leak.
1. Position gasket in sideport of mask assembly (6).
2. Install side voicemitter in sideport, with four beads (7) facing out.
3. Position side voicemitter retainer in sideport; tighten with D-ring on mask carrier strap by turning clockwise until the
mask distorts.
4. Check for proper function (para 2-8).
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TM 09204A/09205A - 20&P/2
2-24. INTERNAL DRINK TUBE NIPPLE
THIS TASK COVERS: a. Verification b. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
a. VERIFICATION
NOTE
This procedure can only be performed if the internal drink tube
nipple on the mask has already been replaced
1. Check the internal drink tube nipple.
2. If the mask has the original drink tube nipple (1), the internal drink tube nipple cannot be replaced. Turn in the
facepiece.
3. If the mask has the revised internal drink tube nipple (2), the internal drink tube nipple can be replaced. Proceed to
the REMOVAL section of this task.
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TM 09204A/09205A - 20&P/2
b. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
" Use the allen wrench to remove the revised internal drink tube nipple by turning counterclockwise.
c. INSTALLATION
1. Position the revised internal drink tube nipple and screw in by hand.
2. Use the alien wrench to tighten the revised internal drink tube nipple.
3. Check for proper function (para 2-8).
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TM 09204A/09205A - 20&P/2
COMMON (CONT)
2-25. OPTICAL INSERT KIT
THIS TASK COVERS: a. Optical Inserts (Wire) b. Optical Inserts (Plastic)
Removal Removal
Installation Installation
Adjustment
INITIAL SETUP:
Applicable Configurations:
M40A1/M42A2
Tools:
Screwdriver (item 13, app D)
a. OPTICAL INSERTS (WIRE)
REMOVAL
Grasp center of wire frame (1) and pull from mask assembly (2).
INSTALLATION
NOTE
Remove neutral gray protective outserts prior to installing or
adjusting optical insert.
Remove hood and pull head harness over the front of the mask.
1. Place wire optical inserts (3) in mask assembly with tips of upper portion (4) of wire frame pointing toward you.
2. Insert lower portion (5) of wire frame into bottom of lens cavities.
NOTE
If tips of upper portion of the wire frame protrude into the line of
sight, bend out of vision field as required.
3. Insert upper portion of wire frame into top of lens cavities.
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TM 09204A/09205A - 20&P/2
NOTE
There are four retainers in each lens opening, one on each side,
one at the top and one at the bottom.
4. Locate the four retainers (6) within each lens opening (External view of mask lens opening is provided for clarity).
5. Ensure that wire frame is seated behind the four retainers in each lens opening.
b. OPTICAL INSERTS (PLASTIC)
REMOVAL
1. For routine removal:
a. Fold one lens up and loosen lens carrier set screw (7).
b. Fold other lens up and loosen second lens carrier set screw (8).
c. Remove lens carrier (9) from mount frame (10) by sliding up.
d. Grasp the mount frame at the center (11) and pull to remove.
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COMMON (CONT)
2-25. OPTICAL INSERT KIT (Cont)
b. OPTICAL INSERTS (PLASTIC) (Cont)
REMOVAL (Cont)
2. For non-routine removal:
Grasp the lens carrier (9) and pull from the mask. If the lens carrier separates from the mount frame (10), grasp the
center (11) of the mount frame and pull to remove.
INSTALLATION
NOTE
Remove neutral gray protective outserts prior to installing or
adjusting optical insert. Remove hood and pull head harness
over the front the mask.
Some masks have smaller lens wells and will require extra effort
in aligning and connecting the hoop ends.
1. Place the mount frame into the mask assembly (2).
2. Position the center block between the mask lenses, and press into place on bridge of mask.
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TM 09204A/09205A - 20&P/2
NOTE
There are four retainers in each lens opening, one on each side,
one at the top and one at the bottom.
3. Locate the four retainers (6) within each lens opening (External view of mask lens opening is provided for clarity).
4. Ensure that mount frame is seated behind the four retainers in each lens opening.
5. Position mount hoops (12) into the mask lens cavities.
6. Turn mask over and do the next step looking through the eyelens.
7. Spread apart the top and bottom of the hoops until the ends of the mount hoops lock into place.
NOTE
Before attempting to install the prescription lens carrier, loosen
the set screws until the points are flush with the surface of the
mount block.
8. The lens carrier (9) is installed by alining the carrier's mounting block (13) with the groove (14) of the mount frame
(10) and sliding the carrier into place.
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COMMON (CONT)
2-25. OPTICAL INSERT KIT (Cont)
b. OPTICAL INSERTS (PLASTIC) (Cont)
ADJUSTMENT
1. The vertical height of the lens carrier (9) can be adjusted by sliding the carrier upward or downward.
CAUTION
Do not over tighten the set screws or the lens carrier will pop out during use.
2. Following adjustment, secure the lens carrier by tightening the set screws until contact is made with the mount
frame(10).
a. Fold the lens carrier to one side and tighten the set screw (7).
b. Fold the lens carrier to the other side and tighten the second set screw (8).
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TM 09204A/09205A - 20&P/2
M40A1 PECULIAR
2-26. M40A1 FACEPIECE.
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M40A1
Equipment Condition:
None
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
1. Remove and save outserts (see Operator's Manual).
2. Remove and save Optical Insert Kit, if installed (para 2-25).
3. Remove and save filter canister (see Operator's Manual).
4. Remove and save the quick doff hood (see Operator's Manual).
5. Remove and save the universal second skin (see Operator's Manual).
b. INSTALLATION
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
1. Install the universal second skin (see Operator's Manual).
2 Install the quick doff hood (see Operator's Manual).
2. Install filter canister (see Operator's Manual).
3. Install Optical Insert Kit, if required. (para 2-25)
4. Install outserts (see Operator's Manual).
5. Return to paragraph 2-7 to adjust mask assembly at initial fitting.
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TM 09204A/09205A - 20&P/2
M42A2 PECULIAR
2-27. M42A2 FACEPIECE.
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M42A2
Equipment Condition:
None
a. REMOVAL
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
1. Remove and save outserts (see Operator's Manual).
2. Remove and save Optical Insert Kit, if installed (para 2-25).
3. Remove and save hose assembly and filter canister (see Operator's Manual).
4. Remove and save detachable microphone (see Operator's Manual).
5. Remove and save universal second skin (see Operator's Manual).
6. Remove and save the quick doff hood (see Operator's Manual).
b. INSTALLATION
CAUTION
Do not scratch plastic eyelens while performing maintenance procedures.
1. Install universal second skin (see Operator's Manual).
2 Install the quick doff hood (see Operator's Manual).
3. Install detachable microphone (see Operator's Manual).
4. Install hose assembly and filter canister (see Operator's Manual).
5. Install Optical Insert Kit, if required (para 2-25).
6 Install outserts (see Operator's Manual).
7. Return to paragraph 2-7 to adjust mask assembly at initial fitting.
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2-28. CLAMP COVER
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M42A2
a. REMOVAL
1. Pull up on flange of clamp cover (1) and work clamp cover free from hose (2).
2. Work clamp cover off end of hose.
b. INSTALLATION
1. Work clamp cover over end of hose.
2. Pull up on flange of clamp cover and position clamp cover over hose. Make sure that clamp cover fully covers end
of hose.
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TM 09204A/09205A - 20&P/2
M42A2 PECULIAR (CONT)
2-29. PORT GASKET
THIS TASK COVERS: a. Removal b. Installation
INITIAL SETUP:
Applicable Configurations:
M42A2
a. REMOVAL
1. Remove filter canister. (See Operator's Manual)
2. Remove gasket (1) from hose end (2).
b. INSTALLATION
1. Install gasket in hose end. Make sure gasket is fully seated in hose end.
2. Install filter canister. (See Operator's Manual)
3. Check for proper function (para 2-8).
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TM 09204A/09205A - 20&P/2
SECTION VIII. CLEANING AND SANITIZING
2-30. CLEANING M40A1
THIS TASK COVERS: a. Cleaning M40A1 mask assembly b. Cleaning improved field mask carrier
INITIAL SETUP:
Applicable Configurations:
M40A1
References:
TM 3-4240-346-10
Materials/Parts:
Cheesecloth (item 7, app D)
Gloves (item 8, app D)
Isopropyl alcohol (item 9, app D)
Lens brush (item 2, app D)
Optical lens cleaning compound (item 6, app D)
Pail (item 12, app D)
Scrub brush (item 3, app D)
Soap (item 15, app D)
a. CLEANG M40A1 MASK ASSEMBLY
CAUTION
DO NOT use hot or boiling water to clean the mask. Damage to
the mask may result. Use warm (comfortable to the touch)
water.
NOTE
Masks are to be cleaned as often as is required. However,
MASK MUST BE CLEANED AND SANITIZED BEFORE
TRANSFERG TO ANOTHER SOLDIER.
Use only potable water to clean mask.
Cleaning may be performed by the operator but must be closely
supervised and inspected by the NBC NCO or other trained
personnel.
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2-30. CLEANING M40A1 (Cont)
a. CLEANING M40A1 MASK ASSEMBLY (Cont)
1. Remove mask assembly from the mask carrier.
2. Remove filter canister, quick doff hood, universal second skin and outserts (see Operator's Manual) or second skin
(see Operator's Manual) or universal second skin (USMC only) (see Operator's Manual).
3. Remove outlet valve cover and outlet valve disk (para 2-22).
4. Remove greasy or oily substances from mask assembly (1) with isopropyl alcohol (item 9, app D) on a cheesecloth
(item 7, app D).
5. There are two methods of cleaning. The first is for light cleaning after normal operations; the second is for heavy
cleaning after extensive use.
a. Light cleaning
(1) Dip cheesecloth (item 7, app D) in warm soapy water and wring cloth almost dry. Lens brush may also be
used. Clean mask assembly, universal second skin (2), quick doff hood (3), or second skin (4) or universal
second skin (USMC only) (5), outlet valve cover (6), outlet valve disk (7) and one-piece hood (8) inside and
out with the cheesecloth (item 7, app D).
(2) Rinse by wiping with cheesecloth (item 7, app D) that has been dipped in warm clear water and wrung
almost dry.
b. Heavy cleaning
(1) Remove head harness (9) (para 2-17).
(2) The NBC NCO will provide a pail (item 12, app D) with warm (comfortable to the touch) water for cleaning
mask components. (If the NBC NCO feels it is necessary, a pail with soap and water may be provided for
cleaning and a pail of water will be provided for rinsing the mask components.)
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TM 09204A/09205A - 20&P/2
(3) Immerse the facepiece (10), outlet valve cover (6), outlet valve disk (7), universal second skin (2), quick
doff hood (3), or second skin (4), or universal second skin (USMC only) (5), or the one-piece hood (8) and
agitate until all sand and dirt has been removed.
(4) Rinse in clear, warm water.
6. Dry facepiece (10), universal second skin (2), quick doff hood (3), or second skin (4) or universal second skin
(USMC only) (5), outlet valve cover (6), outlet valve disk (7) and one-piece hood (8) with cheesecloth (item 7,
app D) or allow to air dry.
7. Clean eyelens (11) and outserts (12) with soap (item 15, app D) and water or optical lens cleaning compound
(item 6, app D).
8. Clean the drinking system. Fill the canteen (13) with water, loosen the M1 canteen cap (14), connect the external
drink tube (15) to the M1 canteen cap, hold the mask upside down with the internal drink tube (16) facing away
from the mask and allow water to flow through the drinking system. Repeat the process twice.
NOTE
If you are sanitizing the mask, DO NOT reinstall any
components. Go to paragraph 2-31, Sanitizing M40A1.
9. Install universal second skin (2) and quick doff hood (3) (See Operator's Manual) or second skin (4) (see
Operator's Manual) or universal second skin (USMC only) (5) (see Operator's Manual) when used with hooded
overgarment.
10. Install clear outserts (See Operator's Manual).
11. Install outlet valve cover and outlet valve disk (para 2-22).
12. Install filter canister (See Operator's Manual).
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2-30. CLEANING M40A1 (CONT)
b. CLEANING FIELD MASK CARRIER
CAUTION
Do not use hot water, bleach, or detergents, or soak or immerse
mask carrier to clean it.
1. Empty pockets and contents from improved field mask carrier (17) or field mask carrier (18).
2. Shake improved field mask carrier or field mask carrier upside down to remove dirt and foreign matter.
3. The field mask carrier cannot be turned inside out. Reach into the carrier with a dry brush (item 3, app D) to
remove as much loose dirt, sand, and foreign matter as possible.
4. Turn the improved field mask carrier inside out. Use a dry brush (item 3, app D) to clean dirt, sand, and foreign
matter from the inside of the improved field mask carrier. Make sure you clean the pockets an seams.
5. Turn the improved field mask carrier right side out.
6. Use a dry brush (item 3, app D) to remove excess dirt, sand, and foreign matter from the exterior of the improved
field mask carrier or the field mask carrier.
7. Soak brush (item 3, app D) in pail (item 12, app D) of cool water.
8. Shake brush (item 3, app D) to remove excess water.
9. Clean improved field mask carrier or field mask carrier with brush (item 3, app D) and cool water.
NOTE
If you are sanitizing the mask, DO NOT repack the mask carrier.
10. Insure improved field mask carrier or field mask carrier and mask components are completely dry before repacking
mask.
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TM 09204A/09205A - 20&P/2
2-31. SANITIZING M40A1
THIS TASK COVERS: Sanitizing M40A1 mask assembly
INITIAL SETUP:
Applicable Configurations:
M40A1
References:
TM 3-4240-346-10
Materials/Parts:
Head Harness
Internal Drink Tube
Outlet Valve Disk
Calcium Hypochlorite (item 5, app D)
Cheesecloth (item 7, app D)
Gloves (item 8, app D)
Pail (item 12, app D)
SANITIZING M40A1 MASK ASSEMBLY
WARNING
Wear gloves to protect hands.
NOTE
WHEN YOU SANITIZE A MASK, USE ONLY POTABLE
WATER.
SANITIZING IS REQUIRED BEFORE MASK IS
TRANSFERRED TO ANOTHER SOLDIER AND WHEN
THE MASK IS TURNED IN AS SERVICEABLE
EXCESS.
Sanitizing may be performed by the operator but must
be closely supervised and inspected by the NBC NCO or
other trained personnel.
THE MASK MUST BE CLEANED PRIOR TO
SANITIZING. GO TO PARAGRAPH 2-34, CLEANING
M40A1 MASK AND MASK CARRIER.
1. Remove head harness (para 2-19) and discard.
2. Remove airflow deflector, inlet valve disk and inlet valve body (para 2-21)
3. Remove nosecup valve disks. (para 2-20).
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2-31. SANITIZING M40A1 (CONT)
SANITIZING M40A1 MASK ASSEMBLY (CONT)
NOTE
DO NOT remove internal drink tube if mask is to be
retained by the same soldier. Sanitize installed internal
drink tube using steps 7 through 20. Remove and
discard the internal drink tube only if the mask is to be
reissued to another soldier.
4. Remove internal drink tube (para 2-17) and discard.
5. Remove outlet valve disk (para 2-22 ) and discard.
NOTE
Prepare enough sanitizing solution to cover facepiece.
6. Add level 1/2 teaspoon of calcium hypochlorite (item 5, app D) to each gallon of clean water in a utility pail (item
12, app D).
WARNING
Assure that calcium hypochlorite if fully dissolved.
Drinking system can be damaged resulting in leaks and
hazard to personnel.
7. Mix thoroughly for 30 seconds to dissolve calcium hypochlorite.
8. Remove M1 canteen cap (1) and fill canteen (2) with this solution and put M1 canteen cap on canteen.
9. Save the rest of the solution for sanitizing the facepiece (3).
10. Open protective cover on M1 canteen cap. Position facepiece face-up.
11. Attach quick disconnect coupling (4) to M1 canteen cap.
12. Invert canteen above facepiece. Squeeze canteen to force the sanitizing solution through the quick disconnect
coupling .
13. Lower canteen to upright position or squeeze sides to vent canteen. Use entire contents and rinse twice with clear
water in the same manner.
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14. Immerse facepiece (3), outserts (5), airflow deflector (6), outlet valve cover (7), one piece hood (8), quick doff
hood (9), second skin (10) or universal second skin (11) or universal second skin (USMC only) (12) and agitate for
5 minutes in sanitizing solution.
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2-31. SANITIZING M40A1 (CONT)
SANITIZING M40A1 MASK ASSEMBLY (CONT)
15. Rinse twice in clear warm water, agitating 2 or 3 minutes each time.
16. Connect Ml canteen cap (I) to the quick disconnect coupling (4) to drain excess water.
17. Dry all parts with cheesecloth (item 7, app D) or allow to air dry.
NOTE
Discard head harness, outlet valve disks, and internal
drink tube and replace with new parts.
CAUTION
Insure all the mask components are completely dry
before reassembling mask.
18. Install head harness (para 2-19).
19. Install inlet valve disk, inlet valve body, and airflow deflector (para 2-21).
20. Install outlet valve disk (para 2-22).
21. Install nosecup valve disk (para 2-20).
22. Install internal drink tube (para 2-17).
23. Install remaining items on mask and repack mask carrier (Operator's Manual).
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2-32. CLEANING M42A2
THIS TASK COVERS: a. Cleaning M42A2 mask assembly b. Cleaning mask carrier
INTIAL SETUP:
Applicable Configurations:
M42A2
References:
TM 3-4240-346- 10
Materials/Parts:
Cheesecloth (item 7, app D)
Gloves (item 8, app D)
Isopropyl alcohol (item 9, app D)
Lens brush (item 2, app D)
Optical lens cleaning compound (item 6, app D)
Pail (item 12, app D)
Scrub brush (item 3, app D)
Soap (item 15, app D)
a. CLEANING M42A2 MASK ASSEMBLY
CAUTION
DO NOT use hot or boiling water to clean the mask.
Damage to the mask may result. Use warm (comfortable
to the touch) water.
NOTE
Masks are to be cleaned as often as is required.
However, MASK MUST BE CLEANED AND SANITIZED
BEFORE TRANSFERRINGTO ANOTHER SOLDIER.
Use only potable water to clean mask. Cleaning may be
performed by the operator but must be closely
supervised and inspected by the NBC NCO or other
trained personnel.
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2-32. CLEANING M42A2 (CONT)
a. CLEANING M42A2 MASK ASSEMBLY (CONT)
1. Remove mask assembly from the mask carrier.
2. Remove canister carrier, hose, quick doff hood, universal second skin, and outserts (see Operator's Manual) or
second skin (see Operator's Manual), or universal second skin (USMC only) (see Operator's Manual).
3. Remove detachable microphone (see Operator's Manual) outlet valve cover and outlet valve disk (para 2-22).
4. Remove greasy or oily substances from mask assembly (1) with isopropyl alcohol on a cheesecloth (item 7, app
D).
5. There are two methods of cleaning. The first is for light cleaning after normal operations; the second is for heavy
cleaning after extensive use.
a. Light cleaning
(1) Dip cheesecloth in warm soapy water and wring cloth almost dry. Lens brush may also be used. Clean
mask assembly, universal second skin (2), quick doff hood (3) or second skin (4) or universal second skin
(USMC only) (5), outlet valve cover (6), outlet valve disk (7), improved canister carrier (8), detachable
microphone (9), and one piece hood (10) inside and out with the cheesecloth (item 7, app D).
(2) Rinse by wiping with cheesecloth (item 7, app D) that has been dipped in warm clear water and wrung
almost dry.
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b. Heavy cleaning
(1) Remove head harness (para 2-17).
(2) The NBC NCO will provide a pail with warm (comfortable to the touch) water for cleaning mask
components. (If the NBC NCO feels it is necessary, a pail (item 3, app D), with soap and water may be
provided for cleaning and a pail of water will be provided for rinsing the mask components.)
(3) Dip cheesecloth (item 7, app D) in warm soapy water and wring cloth almost dry. Lens brush may also be
used. Clean head harness (10) and detachable microphone (9).
(4) Immerse the facepiece (11), universal second skin (2), quick doff hood (3) or second skin (4) or universal
second skin (USMC only) (5), outlet valve cover (6), outlet valve disk (7), improved canister carrier (8) or
one-piece hood (10) and agitate until all dirt, sand, and foreign matter has been removed.
(5) Rinse in clear, warm water.
6. Dry facepiece (11), head harness ( 12), universal second skin (2), quick doff hood (3) or second skin (4) or
universal second skin (USMC only) (5), outlet valve cover (6), outlet valve disk (7), improved canister carrier (8),
detachable microphone (9), and one piece hood (10) with cheesecloth (item 7, app D) or allow to air dry.
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2-32. CLEANING M42A2 (CONT)
a. CLEANING M42A2 MASK ASSEMBLY (CONT)
7. Wipe outside of hose (12) with isopropyl alcohol (item 9, App D) on a cheesecloth.
8. Clean eyelens (13) and outserts (14) with soap (item 15, app D) and water or optical lens cleaning compound
(item 6, app D).
9. Clean the drinking system. Fill the canteen (15) with water, loosen the M1 canteen cap (16), connect the external
drink tube (17) to the M1 canteen cap, hold the mask upside down with the internal drink tube (18) facing away
from the mask and allow water to flow through the drinking system. Repeat the process twice.
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NOTE
If you are sanitizing the mask. DO NOT reinstall any
components. Go to paragraph 2-33, Sanitizing M42A2.
10. Install universal second skin (2) and quick doff hood (3) (See Operator's Manual) or universal second skin (4) (see
Operator's Manual) or universal second skin (USMC only) (5) (see Operator's Manual) when used with hooded
overgarment.
11. Install clear outserts (See Operator's Manual).
12. Install outlet valve cover, and outlet valve disk (para 2-22).
13. Install universal second skin (3), or second skin (4), or universal second skin (USMC only) (5) and quick doff hood
(3) (See Operator's Manual).
14. Install improved canister carrier and hose assembly (See Operator's Manual).
15. Install detachable microphone (see Operator's Manual).
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2-32. CLEANING M42A2 (CONT)
b. CLEANING MASK CARRIER
CAUTION
Do not use hot water, bleach, or detergents, or soak or
immerse mask carrier to clean it.
1. Empty pockets and contents from combat vehicle mask carrier (19) or field mask carrier (20).
2. Shake combat vehicle mask carrier or field mask carrier upside down to remove dirt and foreign matter.
3. The field mask carrier cannot be turned inside out. Reach into the carrier with a dry brush (item 3, app D) to
remove as much loose dirt, sand, and foreign matter as possible.
4. Turn the combat vehicle mask carrier inside out. Use a dry brush (item 3, app D) to clean dirt, sand, and foreign
matter from the inside of the combat vehicle mask carrier. Make sure you clean the pockets and seams.
5. Turn the combat vehicle mask carrier right side out.
6. Use a dry brush (item 3, app D) to remove excess dirt, sand, and foreign matter from the exterior of the combat
vehicle mask carrier or the field mask carrier.
7. Soak brush (item 3, app D) in pail (item 12, app D) of cool water.
8. Shake brush (item 3, app D) to remove excess water.
9. Clean combat vehicle mask carrier or field mask carrier with brush (item 3, app D) and cool water.
NOTE
If you are sanitizing the mask, do not repack the mask
carrier.
10. Insure combat vehicle mask carrier or field mask carrier and mask components are completely dry before
repacking
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2-33. SANITIZING M42A2
THIS TASK COVERS: Sanitizing M42A2 mask assembly
INITIAL SETUP:
Applicable Configurations:
M42A2
References:
TM 3-4240-346- 10
Materials/Parts:
Head Harness
Internal Drink Tube
Outlet Valve Disk
Calcium Hypochlorite (item 5, app D)
Cheesecloth (item 7, app D)
Gloves (item 8, app D)
Pail (item 12, app D)
SANITIZING M42A2 MASK ASSEMBLY
WARNING
Wear gloves to protect hands.
NOTE
WHEN YOU SANITIZE A MASK, USE ONLY POTABLE
WATER.
SANITIZING IS REQUIRED BEFORE MASK IS
TRANSFERRED TO ANOTHER SOLDIER AND
WHENTHE MASKIS TURNED IN AS SERVICEABLE
EXCESS.
Sanitizing may be performed by the operator but must
be closely supervised and inspected by the NBC NCO or
other trained personnel.
THE MASK MUST BE CLEANED PRIOR TO
SANITIZING. GO TO PARAGRAPH 2-36, CLEANING
M42A2 MASK AND MASK CARRIER.
1. Remove head harness (para 2-19) and discard.
2. Remove airflow deflector, inlet valve disk and inlet valve body (para 2-21)
3. Remove nosecup valve disks. (para 2-20).
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2-33. SANITIZING M42A2 (CONT)
SANITIZING M42A2 MASK ASSEMBLY (CONT)
NOTE
DO NOT remove internal drink tube if mask is to be
retained by the same soldier. Sanitize installed internal
drink tube using steps 7 through 20. Remove and
discard the internal drink tube only if the mask is to be
reissued to another soldier.
4. Remove internal drink tube (para 2-17) and discard.
5. Remove outlet valve disk (para 2-22) and discard.
CAUTION
Set detachable microphone aside so that it does not get
wet or damaged.
6. Remove and save the detachable microphone (See Operator's Manual).
NOTE
Prepare enough sanitizing solution to cover facepiece.
7. Add level 1/2 teaspoon of calcium hypochlorite (item 5, app D) to each gallon of clean water in a utility pail (item
12, app D).
WARNING
Assure that calcium hypochlorite is fully dissolved.
Drinking system can be damaged resulting in leaks and
hazard to personnel.
8 Mix thoroughly for 30 seconds to dissolve calcium hypochlorite.
9. Remove M1 canteen cap (1) and fill canteen (2) with this solution and put M1 canteen cap on canteen.
10. Save the rest of the solution for sanitizing the facepiece (3).
11. Open protective cover on M1 canteen cap. Position facepiece face-up.
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12. Attach quick disconnect coupling (4) to M1 canteen cap.
13. Invert canteen above facepiece. Squeeze canteen to force the sanitizing solution through the quick disconnect
coupling.
14. Lower canteen to upright position or squeeze sides to vent canteen. Use entire contents and rinse twice with clear
water in the same manner.
15. Immerse facepiece (3), outserts (5), airflow deflector (6), outlet valve cover (7), quick doff hood (8), universal
second skin (9) or second skin (10) or universal second skin (USMC only) (11), or one-piece hood (12) and agitate
for 5 minutes in sanitizing solution.
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2-33. SANITIZING M42A2 (CONT)
SANITIZING M42A2 MASKASSEMBLY (CONT)
16. Rinse twice in clear warm water, agitating 2 or 3 minutes each time.
17. Connect M1 canteen cap (1) to the quick disconnect coupling (4) to drain excess water.
18. Dry all parts with cheesecloth (item 7, app D) or allow to air dry.
NOTE
Discard head harness, outlet valve disks, and internal
drink tube and replace with new parts.
CAUTION
Insure all the mask components are completely dry
before reassembling mask.
19. Install head harness (para 2-19).
20. Install inlet valve disk, inlet valve body, and airflow deflector (para 2-21).
21. Install outlet valve disk (para 2-22).
22. Install nosecup valve disk (para 2-20).
23. Install internal drinktube (para 2-17).
24. Install remaining items on mask and repack mask carrier (Operator's Manual).
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SECTION IX. PREPARATION FOR STORAGE OR SHIPMENT
2-34. PREPARATION FOR STORAGE OR SHIPMENT
CAUTION
Store masks in a cool dry place. Heat and moisture will
damage the mask and the filter material.
a. Preparation for storage or shipment instructions are identical for the M40A1 and the M42A2, except for paragraph
references. The appropriate references for cleaning or performing other functions are identified by mask.
b. Storage by Using Unit. Use either the fiberboard boxes or the plywood boxes for unit storage by stacking them on
their sides to form a bank of storage cells. Fiberboard boxes should not be stacked more than three high.
c. Faceform. Replace interior plastic faceform packaging support if mask will be stowed longer than 30 days.
d. Temporary Storage by Using Unit.
1. Hang the carrier either by the shoulder strap or by the D-ring on the short strap on top of the carrier.
2. Stow straps as directed by the local unit SOP. Both straps may be hooked to the D-ring by their snap
hooks.
e. Shipment of mask assembly.
WARNING
HEALTH/ENVIRONMENTAL HAZARD
" There are two Mask Filter Canisters, the C2 and the
C2A1.
" The C2 canister contains Chromium VI and damaged
or unusable canisters are considered Hazardous
Waste. (Chromium VI is a known carcinogen if
inhaled or swallowed.)
" The C2A1 canister is chromium-free but must
continue to be disposed of in accordance with State
and Local Environmental Laws.
" DO NOT throw away damaged or unusable canisters
as ordinary trash.
" DO turn in damaged or unusable canisters to your
hazardous waste management office or Defense
Reutilization and Marketing Office (DRMO).
CAUTION
Package mask carefully to prevent damage during
shipment.
1. Clean masks (M40A1 - para 2-30), (M42A2 - para 2-32).
2 Do not ship canister with mask. Turn canisters in to DRMO or, in accordance with state and local environmental
laws, unit SOP, for disposal.
3. Install clear outserts onto lens of mask facepiece. Place operator's manual into a ziplock bag and close. Stow
other outserts, waterproof bag and packaged operator's manual in inside pockets of carrier.
4. Pull hood over the front of the mask facepiece.
5. Loosen head harness straps and install packaging faceform into mask facepiece cavity. Tighten the head harness
straps evenly around faceform.
6. Wrap mask facepiece with one complete turn of cushioning material (item 19 app D). Overlap and secure ends
with tape (item 20, app D).
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2-34. PREPARATION FOR STORAGE OR SHIPMENT (CONT)
7. Install wrapped mask facepiece in the carrier with lenses facing upward and close flaps tightly.
8. Place, carriers, packaged as above, (maximum 8 each) in one layer into a weather-resistant shipping container
(item 18, app D) or equivalent. The voids in box shall be filled with cushioning material (item 19, app D).
9. Pack the shipping container into a wooden shipping container (item 18, app D). Use six cleated box fasteners to
secure box lid, applying two on each side and one on each end.
10. Secure a shipping document envelope on the side on the shipping container with an enclosed DD Form 134 for
each NSN being shipped (AR 725-50, See II, Par 7-11).
f. Shipment of facepiece.
CAUTION
Package mask carefully to prevent damage during
shipment.
1. Clean facepiece (M40A1 - para 2-30), (M42A2 - para 2-32).
2. Loosen head harness straps and install packaging faceform into mask facepiece cavity. Tighten the head harness
straps evenly around faceform.
3. Wrap mask facepiece with one complete turn of cushioning material (item 19 app D). Overlap and secure ends
with tape (item 20, app D).
4. Place, carriers, packaged as above, (maximum 8 each) in one layer into a weather-resistant shipping container
(item 18, app D) or equivalent. The voids in box shall be filled with cushioning material (item 19, app D).
5. Secure a shipping document envelope on the side on the shipping container with an enclosed DD Form 134 for
each NSN being shipped (AR 725-50, See II, Par 7-11).
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APPENDIX A
REFERENCES
A-1. SCOPE
This appendix lists all forms, field manuals, technical manuals, and miscellaneous publications referenced in this manual.
A-2. FORMS
DA Form 2028 .................................................................................. Recommended Changes to Publications and
Blank Forms
DA Form 2028-2 ............................................................................... Recommended Changes to Equipment Technical
Publications
DA Form 2404 .................................................................................. Equipment Inspection and Maintenance
Worksheet
DD Form 314 .................................................................................... Preventive Maintenance Schedule and Record
NAVMC Form 10772......................................................................... Recommended Change to
Publications/Logistics-Maintenance Data Coding
SF 364.............................................................................................. Report of Discrepancy (ROD)
SF 368.............................................................................................. Product Quality Deficiency Report
A-3. FIELD MANUALS
FM 3-4.............................................................................................. NBC Protection
FM 21-11 .......................................................................................... First Aid for Soldiers
A-4. TECHNICAL MANUALS
TM 3-4240-346-10 ............................................................................ Chemical-Biological Mask: Field M40A1, Combat
Vehicle M42A2
TM 43-0002-31 ................................................................................. Destruction of Chemical Weapons and Defense
Equipment to Prevent Enemy Use
TM 4700-15/1 ................................................................................... Ground Equipment Record Procedures
A-5. TRAINING MATERIALS
TVT 3-90........................................................................................... M41 Protection Assessment Testing System (45
minutes) - PIN 710502 - Video Tape
TVT 3-95........................................................................................... M40/M42 Protective Mask Unit Level Operations
PIN 710665 - Video Tape
TVT 3-96........................................................................................... M40/M42 Protective Mask Operator Level
Operations - PIN 710719 - Video Tape
TVT 3-97........................................................................................... M41 Protection Assessment Testing System (9.5
minutes) - PIN 710411 - Video Tape
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A-6. MISCELLANEOUS
AR 70-38 .......................................................................................... Research, Development, Test and Evaluation of
Material for Extreme Climatic Conditions
AR 700-84 ........................................................................................ Issue and Sale of Personal Clothing
AR 725-50 ........................................................................................ Requisition, Receipt, and Issue System
CTA 8-100 ........................................................................................ Army Medical Department Expendable/Durable
Items
CTA 50-970 ...................................................................................... Expendable/Durable Items (Except Medical,
Class V, Repair Parts, and Heraldic items)
DA PAM 738-750 .............................................................................. The Army Maintenance Management System
(TAMMS)
MCO 4855.10 ................................................................................... Product Quality Deficiency Report (PQDR)
MIL-STD-129 .................................................................................... Marking for Shipment and Storage
SB 3-30-2 ......................................................................................... Chemical-Biological Canisters and Filter
Elements: Serviceability Lists Protection
Assessment Test System (Provided with end
item, commercial manual)
TC 3-41 ............................................................................................ Protection Assessment Test System
A-2
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APPENDIX B
MAINTENANCE ALLOCATION CHART (MAC)
SECTION I. INTRODUCTION
B-1. THE MAINTENANCE SYSTEM MAC.
a. Parts of the MAC of the M40A1 differ from the MAC of the M42A2. In order to stop any confusion, two separate MACs
are provided. One for the M40A1 and one for the M42A2.
b. This introduction (Section I) provides a general explanation of all maintenance and repair functions authorized at
various maintenance levels under the standard Maintenance System concept.
c. The Maintenance Allocation Chart (MAC) in Section II designates overall authority and responsibility for the
performance of maintenance functions on the identified end item or component The application of the maintenance
functions to the end item or component will be consistent with the capacities and capabilities of the designated
maintenance levels, which are shown on the MAC in column (4) as:
Unit - includes two subcolumns, C (operator/crew) and O (unit) maintenance.
Direct Support - includes an F subcolumn.
General Support - includes an H subcolumn.
Depot - includes a D subcolumn.
d. Section III lists the tools and test equipment (both special tools and common tool sets) required for each maintenance
function as referenced from Section II.
e. Section IV contains supplemental instructions and explanatory notes for a particular maintenance function.
B-2. MAINTENANCE FUNCTIONS.
Maintenance functions will be limited to and defined as follows:
a. Inspect. To determine the serviceability of an item by comparing its physical, mechanical and /or electrical
characteristics with established standards through examination (e.g., by sight, sound or feel).
b. Test. To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of an
item and comparing those characteristics with prescribed standards.
c. Service. Operations required periodically to keep an item in proper operating condition; i.e. to clean (includes
decontaminate, when required), to preserve, to drain, to paint, or to replenish fuel, lubricants, chemical fluids, or gases.
d. Adjust. To maintain or regulate, within prescribed limits, by bringing into proper or exact position, or by setting the
operating characteristics to specified parameters.
e. Align. To adjust specified variable elements of an item to bring about optimum or desired performance.
f. Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test, measuring, and
diagnostic equipments used in precision measurement. Consists of comparisons of two instruments, one of which is a
certified standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being
compared.
g. Remove/Install. To remove and install the same item when required to perform service or other maintenance
functions. Install may be the act of emplacing, seating, or fixing into position a spare, repair part, or module (component or
assembly) in a manner to allow the proper functioning of an equipment or system.
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TM 3-4240-346-20 & P
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B-2. MAINTENANCE FUNCTIONS (CONT)
h. Replace. To remove an unserviceable item and install a serviceable counter part in its place. "Replace" is authorized
by the MAC and assigned maintenance level is shown as the 3rd position code of the SMR code.
i. Repair. The application of maintenance services including fault location/troubleshooting, removal/installation, and
disassembly/assembly procedures, and maintenance actions to identify troubles and restore serviceability to an item by
correcting specific damage, fault, malfunction, or failure in a part, subassembly, module (component or assembly), end
item, or system.
j. Overhaul. That maintenance effort (service/action) prescribed to restore an item to a completely
serviceable/operational condition as required by maintenance standards in appropriate technical publications (i.e.,
DMWR). Overhaul is normally the highest degree of maintenance performed by the Army. Overhaul does not normally
return an item to like new condition.
k. Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like new
condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel maintenance
applied to Army equipment. The rebuild operation includes the act of returning to zero those age measurements
(hours/miles, etc.) considered in classifying Army equipment/components.
B-3. EXPLANATION OF COLUMNS IN THE MAC, SECTION II.
a. Group Number. (Column(1)). Lists functional group code numbers, the purpose of which is to identify maintenance
significant components, assemblies, subassemblies, and modules with the next higher assembly.
b. Component/Assembly.(Column(2)). Contains the item names of components, assemblies, subassemblies, and
modules for which maintenance is authorized.
c. Maintenance Function. (Column(3)). Lists the functions to be performed on the item listed in column (2).
d. Maintenance Level. (Column (4)). Specifies, each level of maintenance authorized to perform each function listed in
column (3), by indicating work time required (expressed as man-hours in whole hours or decimals) in the appropriate
subcolumn. This work-time figure represents the active time required to perform that maintenance function at the indicated
level of maintenance. If the number or complexity of the tasks within the listed maintenance function vary at different
maintenance levels, appropriate work time figures will be shown for each level. The work time figure represents the
average time required to restore an item (assembly, subassembly, component, module, end item, or system) to a
serviceable condition under typical field operating conditions. This time includes preparation time (including any necessary
disassembly/assembly time), troubleshooting/fault location time, and quality assurance/quality control time in addition to
the time required to perform the specific tasks identified for the maintenance functions authorized by the Maintenance
Allocation Chart.
The symbol designations for the various maintenance levels are as follows:
C .......................................................................Operator or Crew
O .......................................................................Unit Maintenance
F .......................................................................Direct Support Maintenance
H .......................................................................General Support Maintenance
L .......................................................................Specialized Repair Activity (SRA) (USMC - Equipment
Surveillance Unit (ESU))
D .......................................................................Depot Maintenance
e. Tools and Equipment. (Column (5)). Specifies, by code, those common tool sets (not individual tools), and special
tools, TMDE, and support equipment required to perform the designated function.
f. Remarks. (Column(6)). This column shall when applicable, contain a letter code, in alphabetic order, which shall be
keyed to the remarks contained in Section IV.
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B-4. EXPLANATION OF COLUMNS IN TOOL AND TEST EQUIPMENT REQUIREMENTS SECTION III.
a. The tool and test equipment requirements provided in this section are identical for the M40A1 and the M42A2 masks.
b. Reference Code (Column (1)). The tool and test equipment reference code correlates with a code used in the MAC,
Section II, Column (5).
c. Maintenance Level (Column (2)). The lowest level of maintenance authorized to use the tool or test equipment.
d. Nomenclature (Column (3)). Name or identification of the tool or test equipment.
e. National Stock Number. (Column (4)). National Stock Number of the tool or test equipment.
f. Tool Number. (Column (5)). The manufacturer's part number.
B-5. EXPLANATION OF COLUMNS IN REMARKS, SECTION IV.
a. This section is presently identical for the M40A1 and the M42A2 masks.
b. Reference Code (Column (2)). The code recorded in column (6), Section II.
c. Remarks (Column (2)). This column lists information pertinent to the maintenance function being performed as
indicated in the MAC, Section II.
SECTION II. MAINTENANCE ALLOCATION CHARTS
CHEMICAL-BIOLOGICAL MASK: FIELD M40A1
(1) (2) (3) (4) (5) (6)
GROUP COMPONENT/ MAINTENANCE MAINTENANCE LEVEL TOOLS AND REMARKS
NUMBER ASSEMBLY FUNCTION EQUIPMENT CODE
REF CODE
UNIT DIRECT GENERAL DEPOT
SUPPORT SUPPORT
C O F H D
00 Chemical- Inspect 0.3 0.3
Biological Mask: Test 0.1
Combat Vehicle Adjust 0.1
Replace 0.1
Repair 0.3
01 Facepiece Inspect 0.3 0.3
Assembly Test 0.3 0.3
Repair 0.3
Service 0.3 0.3
B-3
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SECTION II. MAINTENANCE ALLOCATION CHARTS (CONT)
CHEMICAL-BIOLOGICAL MASK: COMBAT VEHICLE M42A2
(1) (2) (3) (4) (5) (6)
GROUP COMPONENT/ MAINTENANCE MAINTENANCE LEVEL TOOLS AND REMARKS
NUMBER ASSEMBLY FUNCTION EQUIPMENT CODE
REF CODE
UNIT DIRECT GENERAL DEPOT
SUPPORT SUPPORT
C O F H D
00 Chemical- Inspect 0.3 0.3
Biological Mask: Test 0.1
Combat Vehicle Adjust 0.1
Replace 0.1
Repair 0.3
01 Facepiece
Assembly Inspect 0.3 0.3
Test 0.3 0.3
Repair 0.3
Service 0.3 0.3
02 Canister Carrier Inspect 0.2 0.2
Replace 0.1
Repair 0.1
03 Hose Assembly Inspect 0.1
Replace 0.1
Repair 0.1
SECTION III. TOOL AND TEST EQUIPMENT REQUIREMENTS
TOOL OR TEST MAINTENANCE NOMENCLATURE NATIONAL STOCK TOOL NUMBER
REFERENCE CODE LEVEL NUMBER
1 UNIT Protection Assessment 4240-01-365-8241 5-1-3326
Testing System
SECTION IV. REMARKS
Not Applicable.
B-4
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APPENDIX C
UNIT MAINTENANCE REPAIR PARTS AND SPECIAL TOOLS LIST
Current as of May 1998
SECTION I. INTRODUCTION
C-1. SCOPE.
This RPSTL lists and authorizes spares and repair parts; special tools; special test, measurement, and diagnostic
equipment (TMDE); and other special support equipment required for performance of Unit maintenance of the M40A1 and
the M42A2 Masks. It authorizes the requisitioning, issue, and disposition of spares, repair parts and special tools as
indicated by the source, maintenance and recoverability (SMR) codes.
C-2. GENERAL.
NOTE: Due to Government procurement methods, the appearance of the part you receive may differ from
the illustrations in this TM.
This Repair Parts and Special Tools List is divided into the following sections:
a. Section II. Repair Parts List. A list of spares and repair parts authorized by this RPSTL for use in the performance of
maintenance. The list also includes parts which must be removed for replacement of the authorized parts. Parts lists are
composed of functional groups in ascending alphanumeric sequence with the parts in each group listed in ascending
figure and item number sequence. Bulk materials are listed by item name in FIG. BULK at the end of the Section. Items
listed are shown on the associated illustration.
b. Section III. Special Tools List. Not applicable.
c. Section IV. Cross-Reference Indexes. A list, in National Item Identification Number (NIIN) sequence, of all National
Stock Numbers (NSN) appearing in the listings, followed by a separate list in alphanumeric sequence of all part numbers
appearing in the listings. National stock numbers and part numbers are cross-referenced to each illustration figure and
item number appearance. The figure and item number index lists figure and item numbers in alphanumeric sequence and
cross-references NSN, CAGEC and part numbers.
C-3. EXPLANATION OF COLUMNS (SECTION II AND III).
a. ITEM NO. (Column (1)). Indicates the number used to identify items called out in the illustration.
b. SMR Code (Column (2)). The Source, Maintenance, and Recoverability (SMR) code is a 5-position code containing
supply/requisitioning information, maintenance level authorization criteria, and disposition instruction, as shown in the
following breakout:
Source Maintenance Recoverability
code code code
1st two
positions
XX XX X
3d position 4th position
How you get an item Who can Who can do Who determined disposition
replace, or use the complete repair* action on an unserviceable item
item on the item
*Complete Repair: Maintenance capacity, capability, and authority to perform all corrective maintenance tasks of the
 Repair function in a use/user environment in order to restore serviceability to a failed item.
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C-3. EXPLANATION OF COLUMNS (SECTION II AND III). (CONT)
(1) Source Code. The source code tells you how to get an item needed for maintenance, repair or overhaul of an end
item/equipment. Explanation of source codes follow:
Code Explanation
Explanation
PA Stocked items; use the applicable NSN to request/
PB requisition items with these source codes. They are
PC** authorized to the level indicated by the code entered in
PD the 3d position of the SMR code.
PE
PF **NOTE: Items coded PC are subject to deterioration.
PG
KD Items with these codes are not to be requested/requisi-
KF tioned individually. They are part of a kit which is autho-
KB rized to the maintenance level indicated in the 3d
position of the SMR code. The complete kit must be
requisitioned and applied.
Items with these codes are not to be requested/requisi-
tioned individually. They must be made by bulk material
MO-(Made at Unit AVUM level) which is identified by the part number in the DESCRIP-
MF-(Made at DS/AVIM level) TION AND USABLE ON CODE (UOC) column and listed
MH-(Made at GS level) in the Bulk Material group of the repair parts and special
ML-(Made at Specialized Repair Act (SRA) tools list in this RPSTL. If the item is authorized to you by
MD-(Made at Depot) the 3d position code of the SMR code, but the source
code indicates it is made at a higher level, order the item
from the higher level of maintenance.
AO-(Assembled by Unit/AVUM level) Items with these codes are not to be requested/requisi-
AF-(Assembled by DS/AVIM level) tioned individually. The parts that make up the
AH-(Assembled at GS level) assembled item must be requisitioned or fabricated and
AL-(Assembled by SRA) assembled at the level of maintenance indicated by the
AD-(Assembled by Depot) source code. If the 3d position code of the SMR code
authorizes you to replace the item, but the source code
indicates it is assembled at a higher level, order the item
from the higher level of maintenance.
XA-Do not requisition an "XA" coded item. Order its next higher assembly. (Also, refer to the NOTE below.)
XB-If an "XB" coded item is not available from salvage, order it using the CAGEC and part number given.
XC-Installation drawing, diagram, instruction sheet, field service drawing, that is identified by manufacturer's part number.
XD-Item is not stocked. Order an "XD" coded item through normal supply channels using the CAGEC and part number
given, if no NSN is available.
NOTE: Cannibalization or controlled exchange, when authorized, maybe used as a source of supply for items with the
above source codes, except for those source coded "XA" or those aircraft support items restricted by requirements of AR
750-1.
(2) Maintenance Code. Maintenance codes tell you the level(s) of maintenance authorized to USE and REPAIR
support items. The maintenance codes are entered in the third and fourth positions of the SMR Code as follows:
C-2
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C-3. EXPLANATION OF COLUMNS (SECTION II AND III).
(a) The maintenance code entered in the third position tells you the lowest maintenance level authorized to
remove, replace, and use an item. The maintenance code entered in the third position will indicate authorization to one of
the following levels of maintenance:
Code Application/Explanation
C -Crew or operator maintenance done within Unit or Aviation Unit Maintenance.
O -Unit or Aviation Unit level can remove, replace, and use the item.
F -Direct support or Aviation Intermediate level can remove, replace, and use the item.
H -General support level can remove, replace, and use the item.
L -Specialized repair activity can remove, replace, and use the item (USMC - Equipment Surveillance Unit (ESU)).
D -Depot level can remove, replace, and use the item.
(b) The maintenance code entered in the fourth position tells whether or not the item is to be repaired and
identifies the lowest maintenance level with the capability to do complete repair (i.e., perform all authorized repair
functions). (NOTE: Some limited repair may be done on the item at a lower level of maintenance, if authorized by the
Maintenance Allocation Chart (MAC) and SMR codes). This position will contain one of the following maintenance codes.
Code Application/Explanation
O -Unit or Aviation Unit is the lowest level that can do complete repair of the item.
F -Direct support or Aviation Intermediate is the lowest level that can do complete repair of the item.
H -General support is the lowest level that can do complete repair of the item.
L -Specialized repair activity (designate the specialized repair activity) is the lowest level that can do complete
repair of the item (USMC - Equipment Surveillance Unit (ESU)).
D -Depot is the lowest level that can do complete repair of the item.
Z -Nonreparable. No repair is authorized.
B -No repair is authorized. (No parts or special tools are authorized for the maintenance of a "B" coded item).
However, the item may be reconditioned by adjusting, lubricating, etc., at the user level.
(3) Recoverability Code. Recoverability codes are assigned to items to indicate the disposition action on
unserviceable items. The recoverability code is entered in the fifth position of the SMR Code as follows:
Code Application/Explanation
Z -Nonreparable item. When unserviceable, condemn and dispose of the item at the level of maintenance shown
in 3d position of SMR code.
O -Reparable item. When uneconomically reparable, condemn and dispose of the item at the Unit or Aviation Unit
level.
F -Reparable item. When uneconomically reparable, condemn and dispose of the item at the Direct support or
Aviation Intermediate level.
H -Reparable item. When uneconomically reparable, condemn and dispose of the item at the General support
level.
D -Reparable item. When beyond lower level repair capability, return to depot. Condemnation and disposal of item
not authorized below Depot level.
L -Reparable item. Condemnation and disposal not authorized below Specialized Repair Activity (SRA) (USMC -
Equipment Surveillance Unit (ESU)).
A -Item requires special handling or condemnation procedures because of specific reasons (e.g., precious metal
content, high dollar value, critical material, or hazardous material). Refer to appropriate manuals/directives for
specific instructions.
c. CAGEC (Column (3)). The Commercial and Government Entity Code (CAGEC) is a 5-digit code which is used to
identify the manufacturer, distributor, or Government agency, etc., that supplies the item.
C-3
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C-3. EXPLANATION OF COLUMNS (SECTION II AND III). (CONT)
d. PART NUMBER (Column (4)). Indicates the primary number used by the manufacturer (individual, company, firm,
corporation, or Government activity), which controls the design and characteristics of the item by means of its engineering
drawings, specifications standards, and inspection requirements to identify an item or range of items.
NOTE: When you use an NSN to requisition an item, the item you receive may have a different part number from
the part ordered.
e. DESCRIPTION AND USABLE ON CODE (UOC) (Column (5)). This column includes the following information:
(1)The Federal item name and, when required, a minimum description to identify the item.
(2)The usable on code, when applicable. (See para. C-5, Special Information.)
(3)The statement "END OF FIGURE" appears just below the last item description in Column 5 for a given figure in
both Section II and Section III.
f. QTY. (Column (6)). The QTY (quantity per figure column) indicates the quantity of the item used in the breakout
shown on the illustration figure, which is prepared for a functional group, subfunction group, or an assembly. A "V"
appearing in this column in lieu of a quantity indicates that the quantity is variable and the quantity may vary from
application to application.
C-4. EXPLANATION OF COLUMNS (Section IV).
a. NATIONAL STOCKNUMBER (NSN) INDEX.
(1) STOCK NUMBER column. This column lists the NSN by National Item Identification Number (NIIN) sequence.
The NIIN consists of the last nine digits of the NSN. (i.e.,NSN )
5305-01-674-1467
NIIN
When using this column to locate an item, ignore the first 4 digits of the NSN. However, the complete NSN should be used
when ordering items by stock number.
(2) FIG. column. This column lists the number of the figure where the item is identified/located. The figures are in
numerical order in Section II and III.
(3) ITEM column. The item number identifies the item associated with the figure listed in the adjacent FIG. column.
This item is also identified by the NSN listed on the same line.
b. PART NUMBER INDEX. Part numbers in this index are listed by part number in ascending alphanumeric sequence
(i.e., vertical arrangement of letter and number combination which places the first letter or digit of each group in order A
through Z, followed by the numbers 0 through 9 and each following letter or digit in like order).
(1) CAGEC column. The Commercial and Government Entity Code (CAGEC) is a 5-digit code used to identify the
manufacturer, distributor, or Government agency, etc., that supplies the item.
(2) PART NUMBER column. Indicates the primary number used by the manufacturer (individual, firm, corporation, or
Government activity), which controls the design and characteristics of the item by means of its engineering drawings,
specifications standards, and inspection requirements to identify an item or range of items.
(3) STOCK NUMBER column. This column lists the NSN for the associated part number and manufacturer identified
in the PART NUMBER and CAGEC columns to the left.
(4) FIG. column. This column lists the number of the figure where the item is identified/located in Section II and Ill.
(5) ITEM column. The item number is that number assigned to the item as it appears in the figure referenced in the
adjacent figure number column.
c. FIGURE AND ITEM NUMBER INDEX
(1) FIG. column. This column lists the number of the figure where the item is identified/located in Section II and III.
C-4
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C-4. EXPLANATION OF COLUMNS (SECTION IV).
(2) ITEM column. The item number is that number assigned to the item as it appears in the figure referenced in the
adjacent figure number column.
(3) STOCK NUMBER column. This column lists the NSN for the item.
(4) CAGEC column. The Commercial and Government Entity Code (CAGEC) is a 5-digit code used to identify the
manufacturer, distributor, or Government agency, etc., that supplies the item.
(5) PART NUMBER column. Indicates the primary number used by the manufacturer (individual, firm, corporation, or
Government activity), which controls the design and characteristics of the item by means of its engineering drawings,
specification standards, and inspection requirements to identify an item or range of items.
C-5. SPECIAL INFORMATION.
a. USABLE ON CODE. The usable on code appears in the lower left corner of the Description Column heading. Usable
on codes are shown as "UOC:..." in the Description Column (justified left) on the first line of the applicable item
description/nomenclature. Uncoded items are applicable to all models. Identification of the usable on codes used in the
RPSTL are:
Code Used On
Y73 M40A1FieldMask(Sm.)
7Y3 M40A1 Field Mask (Med.)
73Y M40A1 Field Mask (Lg.)
213 M42A2 Combat Vehicle Mask (Sm.)
21M M42A2 Combat Vehicle Mask (Med.)
21L M42A2 Combat Vehicle Mask (Lg.)
C-6. HOW TO LOCATE REPAIR PARTS.
a. When National Stock Number or Part Number is Not Known.
(1) First. Using the table of contents, determine the functional group or subfunctional group to which the item belongs.
This is necessary since figures are prepared for functional groups and subfunctional groups, and listings are divided into
the same groups.
(2) Second. Find the figure covering the functional group or subfunctional group to which the item belongs.
(3) Third. Identify the item on the figure and use the Figure and Item Number Index to find the NSN.
b. When National Stock Number or Part Number is Known.
(1) First Using the National Stock Number or Part Number Index, find the pertinent National Stock Number or Part
Number. The NSN index is in National Item Identification Number (NIIN) sequence. (see C-4.a(l)). The part numbers in the
Part Number Index are listed in ascending alphanumeric sequence (see C-4.b). Both indexes cross-reference you to the
illustration/figure and item number of the item you are looking for.
(2) Second. Turn to the figure and item number, verify that the item is the one you're looking for, then locate the item
number in the repair parts list for the figure.
C-7. ABBREVIATIONS. Not applicable.
C-5
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
SECTION II
Figure C-1. Chemical Biological Mask: Field M40A1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
(1) (2) (3) (4) (5) (6)
ITEM SMR PART
NO. CODE CAGEC NUMBER DESCRIPTION AND USABLE CODES (UOC) QTY
GROUP 00: CHEMICAL BIOLOGICAL MASK:
FIELD M40A1
FIGURE C-1. CHEMICAL BIOLOGICAL MASK
1 PAODD 81361 5-1-1001-10 FACEPIECE ASSEMBLY..............................................1
UOC: Y73
1 PAODD 81361 5-1-1001-20 FACEPIECE ASSEMBLY..............................................1
UOC: 7Y3
1 PAODD 81361 5-1-1001-30 FACEPIECE ASSEMBLY..............................................1
UOC: 73Y
2 PAOZZ 81361 5-1-1545-20 OUTSERTS, NEUTRAL ................................................1
3 PAOZZ 81361 5-1-1545-10 OUTSERTS, CLEAR.....................................................1
4 PAOZZ 81361 5-1-2775 CARRIER ASSY ...........................................................1
5 PCOZA 81361 5-3-1520 FILTER CANISTER, CHEMICAL...................................1
6 PAOZZ 81349 MILB51170 BAG, WATERPROOFING, C ........................................1
7 PCOZZ 81361 5-1-1003 FACEFORM PACKAGING ............................................1
8 PCOZZ 81361 5-1-27-7 HOOD ASSEMBLY .......................................................1
9 PCOZZ 81361 5-1-3321-10 FACEPIECE, USS ........................................................1
UOC: Y73
9 PCOZZ 81361 5-1-3321-20 FACEPIECE, USS ........................................................1
UOC: 7Y3, 73Y
10 PCOZZ 81361 5-1-2707-1 FACEPIECE SECOND..................................................1
UOC: Y73
10 PCOZZ 81361 5-1-2707-2 FACEPIECE SECOND..................................................1
UOC: 7Y3, 73Y
END OF FIGURE
C-1-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
Figure C-2. Mask Assembly M40A1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
(1) (2) (3) (4) (5) (6)
ITEM SMR PART
NO. CODE CAGEC NUMBER DESCRIPTION AND USABLE CODES (UOC) QTY
GROUP 01: FACEPIECE ASSEMBLY:
FIELD M40A1
FIGURE C-2. FACEPIECE ASSEMBLY
1 PCOZZ 81361 5-1-1081 DISK, VALVE................................................................1
2 PCOZZ 81361 5-1-1085 DRINK TUBE, INTERNAL .............................................1
3 PAOZZ 81361 5-1-2796 HARNESS, HEAD.........................................................1
4 PAOZZ 81361 5-1-1050-10 DEFLECTOR, POST, SUB............................................1
UOC: Y73
4 PAOZZ 81361 5-1-1050-20 DEFLECTOR, POST, SUB............................................1
UOC: 7Y3, 73Y
5 PAOZZ 81361 5-1-1055 DISK, VALVE...............................................................1
6 PAOZZ 81361 5-1-1054 BODY, VALVE ..............................................................1
7 PAOZZ 81361 5-1-1086 QUICK DISCONNECT ..................................................1
8 PAOZZ 81361 5-1-1057 DISK, VALVE................................................................1
9 PAOZZ 81361 5-1-1009 COVER, OUTLET VALVE.............................................1
10 PAOZZ 03038 5-1-1059 RING, RETAINING. INST..............................................1
11 PCOZZ 81361 5-1-1047 DIAPHRAGM, MICROPHONE ......................................1
12 PCOZZ 81361 5-1-1060 GASKET .......................................................................1
END OF FIGURE
C-2-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
Figure C-3. Chemical Biological Mask: Combat Vehicle M42A2
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
(1) (2) (3) (4) (5) (6)
ITEM SMR PART
NO. CODE CAGEC NUMBER DESCRIPTION AND USABLE CODES (UOC) QTY
GROUP 00: CHEMICAL BIOLOGICAL MASK:
FIELD M42A2
FIGURE C-3. CHEMICAL BIOLOGICAL MASK
1 PAODD 81361 5-1-1001-10 FACEPIECE ASSEMBLY..............................................1
UOC: 213
1 PAODD 81361 5-1-1001-20 FACEPIECE ASSEMBLY..............................................1
UOC: 21M
1 PAODD 81361 5-1-1001-30 FACEPIECE ASSEMIBLY.............................................1
UOC: 21L
2 PAOZZ 81361 5-1-3339 MICROPHONE, DETACHABLE ....................................1
3 PAOZZ 81361 5-1-1545-20 OUTSERTS, NEUTRAL ................................................1
4 PAOZZ 81361 5-1-1545-10 OUTSERTS, CLEAR.....................................................1
5 PAOZZ 81361 5-1-2774 CARRIER ASSY ...........................................................1
6 PCOZA 81316 5-3-1520 CANISTER, CHEMICAL-B ............................................1
7 PAOZZ 81349 MILB51170 BAG, WATERPROOFING, C ........................................1
8 PAOZZ 81361 5-1-1003 FACEFORM PACKAGING ............................................1
9 PAOOO 81361 5-1-1963 HOSE ASSEMBLY........................................................1
10 PAOOO 81361 5-1-1971 CANISTER CARRIER ASSEMBLY ...............................1
11 PCOZZ 81361 5-1-2701 HOOD ASSEMBLY .......................................................1
12 PCOZZ 81361 5-1-3321-10 FACEPIECE, USS ........................................................1
UOC: 213
12 PCOZZ 81361 5-1-3321-20 FACEPIECE, USS ........................................................1
UOC: 21M, 21L
13 PCOZZ 81361 5-1-2707-1 FACEPIECE SECOND..................................................1
UOC: 213
13 PCOZZ 81361 5-1-2707-2 FACEPIECE SECOND..................................................2
UOC: 21M, 21L
C-3-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
Figure C-4. Chemical Biological Mask: Combat Vehicle M42A2
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
(1) (2) (3) (4) (5) (6)
ITEM SMR PART
NO. CODE CAGEC NUMBER DESCRIPTION AND USABLE CODES (UOC) QTY
GROUP 01: FACEPIECE ASSEMBLY:
FIGURE C-4. FACEPIECE ASSEMBLY
1 PCOZZ 81361 5-1-1081 DISK, VALVE................................................................1
2 PCOZZ 81361 5-1-1085 DRINK TUBE, INTERNAL .............................................1
3 PAOZZ 81361 5-1-2796 HARNESS, HEAD.........................................................1
4 PAOZZ 81361 5-1-1050-10 DEFLECTOR, POST, SUB............................................1
UOC: 213
4 PAOZZ 81361 5-1-1050-20 DEFLECTOR, POST, SUB............................................1
UOC: 21M, 21L
5 PAOZZ 81361 5-1-1055 DISK, VALVE................................................................1
6 PAOZZ 81361 5-1-1054 BODY, VALVE ..............................................................1
7 PAOZZ 81361 5-1-1086 QUICK DISCONNECT ..................................................1
8 PAOZZ 81361 5-1-1057 DISK, VALVE................................................................1
9 PAOZZ 81361 5-1-1009 COVER, OUTLET VALVE.............................................1
10 PAOZZ 03038 5-1-1059 RING, RETAINING, INST..............................................1
11 PCOZZ 81361 5-1-1047 DIAPHRAGM, MICROPHONE ......................................1
12 PCOZZ 81361 5-1-1060 GASKET .......................................................................1
END OF FIGURE
C-4-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
Figure C-5. Canister Carrier Assembly
(1) (2) (3) (4) (5) (6)
ITEM SMR PART
NO. CODE CAGEC NUMBER DESCRIPTION AND USABLE CODES (UOC) QTY
GROUP 02: CANNISTER CARRIER
FIGURE C-10. CANISTER CARRIER ASSEMBLY
1 PAOZZ 81361 5-1-1960-10 DISCONNECT, ASSY ARM ..........................................1
END OF FIGURE
C-5-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION II
Figure C-6. Hose Assembly
(1) (2) (3) (4) (5) (6)
ITEM SMR PART
NO. CODE CAGEC NUMBER DESCRIPTION AND USABLE CODES (UOC) QTY
GROUP 03: HOSE ASSEMBLY
FIGURE C-11. HOSE ASSEMBLY
1 PCOZZ 81361 5-1-1522 GASKET, CONNECTOR...............................................1
2 PAOZZ 81361 5-1-1524 COVER, CLAMP...........................................................2
END OF FIGURE
C-6-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION III. SPECIAL TOOLS LIST
Not Applicable
C-7-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION IV
CROSS-REFERENCE INDEXES
NATIONAL STOCK NUMBER INDEX
STOCK NUMBER FIG. ITEM STOCK NUMBER FIG ITEM
4240-00-377-9401 C-1 6 4240-01-413-1540 C-1 10
C-3 7 C-3 13
4820-01-226-7005 C-2 6 4240-01-413-1543 C-1 10
C-4 6 C-3 13
5330-01-231-3877 C-6 1 5965-01-414-2257 C-3 2
4240-01-260-8696 C-6 2 4240-01-415-4517 C-1 1
4240-01-260-8697 C-1 7 C-3 1
C-3 8 4240-01-415-4518 C-1 1
4240-01-260-8698 C-1 4 C-3 1
4240-01-260-8699 C-2 9 4240-01-416-0430 C-1 1
C-4 9 C-3 1
5365-01-260-8700 C-2 10
C-4 10
5965-01-260-8701 C-2 11
C-4 11
5330-01-260-8702 C-2 12
C-4 12
4820-01-260-8703 C-2 1
C-4 1
4240-01-260-8706 C-1 2
C-3 3
4240-01-260-8707 C-1 3
C-3 4
4820-01-260-8709 C-2 8
C-4 8
4820-01-260-8710 C-2 5
C-4 5
4240-01-260-8711 C-2 2
C-4 2
4240-01-267-8161 C-2 4
C-4 4
4240-01-268-0392 C-2 4
C-4 4
5965-01-277-8689 C-2 10
4240-01-361-1319 C-1 5
C-3 6
4240-01-376-0471 C-2 9
C-3 12
4240-01-376-1382 C-3 10
4240-01-376-3152 C-1 8
C-3 11
4240-01-378-6479 C-3 9
4240-01-381-1568 C-1 9
C-3 12
4730-01-391-8461 C-2 7
C-4 7
4730-01-392-2173 C-5 1
4240-01-399-3350 C-3 5
I-1
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION IV
CROSS-REFERENCE INDEXES
PART NUMBER INDEX
CAGEC PART NUMBER STOCK NUMBER FIG. ITEM
81349 MILB51170 4240-00-377-9401 C-1 6
C-3 7
81361 5-1-1001-10 4240-01-415-4517 C-1 1
C-3 1
81361 5-1-1001-20 4240-01-415-4518 C-1 1
C-3 1
81361 5-1-1001-30 4240-01-416-0430 C-1 1
C-3 1
81361 5-1-1003 4240-01-260-8697 C-1 7
C-3 8
81361 5-1-1009 4240-01-260-8699 C-2 9
C-4 9
81361 5-1-1047 5965-01-260-8701 C-2 11
C-4 11
81361 5-1-1050-10 4240-01-267-8161 C-2 4
C-4 4
81361 5-1-1050-20 4240-01-268-0392 C-2 4
C-4 4
81361 5-1-1054 4820-01-226-7005 C-2 6
C-4 6
81361 5-1-1055 4820-01-260-8710 C-2 5
C-4 5
81361 5-1-1057 4820-01-260-8709 C-2 8
C-4 8
81361 5-1-1059 5365-01-260-8700 C-2 10
C-4 10
81361 5-1-1060 5330-01-260-8702 C-2 12
C-4 12
81361 5-1-1081 4820-01-260-8703 C-2 1
C-4 1
81361 5-1-1085 4240-01-260-8711 C-2 2
C-4 2
81361 5-1-1086 4730-01-391-8461 C-2 7
C-4 7
81361 5-1-1522 5330-01-231-3877 C-6 1
81361 5-1-1524 4240-01-260-8696 C-6 2
81361 5-1-1545-10 4240-01-260-8707 C-1 3
C-3 4
81361 5-1-1545-20 4240-01-260-8706 C-1 2
C-3 3
81361 5-1-1960-10 4730-01-392-2173 C-5 1
81361 5-1-1963 4720-01-378-6479 C-3 9
81361 5-1-1971 4240-01-376-1382 C-3 10
81361 5-1-2701 4240-01-376-3152 C-1 8
C-3 11
I-2
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION IV
CROSS-REFERENCE INDEXES
PART NUMBER INDEX
CAGEC PART NUMBER STOCK NUMBER FIG. ITEM
81361 5-1-2707-1 4240-01-376-0471 C-1 10
C-3 12
81361 5-1-2707-2 4240-01-381-1568 C-1 10
C-3 12
81361 5-1-2774 4240-01-399-3350 C-3 5
81361 5-1-2775 4240-01-260-8698 C-1 4
81361 D5-2-1661 4240-01-223-7313 C-2 3
C-4 3
81361 5-1-3321-10 4240-01-413-1540 C-1 9
C-3 13
81361 5-1-3321-20 4240-01-413-1543 C-1 9
C-3 13
81361 5-1-3339 5965-01-414-2257 C-3 2
81361 5-3-1520 4240-01-361-1319 C-1 5
C-3 6
I-3
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION IV
CROSS-REFERENCE INDEXES
FIGURE AND ITEM NUMBER INDEX
FIG ITEM STOCK NUMBER CAGEC PART NUMBER
C-1 1 4240-01-415-4517 81361 5-1-1001-10
C-1 1 4240-01-415-4518 81361 5-1-1001-20
C-1 1 4240-01-416-0430 81361 5-1-1001-30
C-1 2 4240-01-260-8706 81361 5-1-1545-20
C-1 3 4240-01-260-8707 81361 5-1-1545-10
C-1 4 4240-01-260-8698 81361 5-1-2775
C-1 5 4240-01-361-1319 81361 5-3-1520
C-1 6 4240-00-377-9401 81349 MILB51170
C-1 7 4240-01-260-8697 81361 5-1-1003
C-1 8 4240-00-376-3152 81361 5-1-2701
C-1 9 4240-01-376-0471 81361 5-1-1707-1
C-1 9 4240-01-381-1568 81361 5-1-2707-2
C-1 10 4240-01-413-1540 81361 5-1-3321-10
C-1 10 4240-01-413-1543 81361 5-1-3321-20
C-2 1 4820-01-260-8703 81361 5-1-1081
C-2 2 4240-01-260-8711 81361 5-1-1085
C-2 3 81361 5-1-2796
C-2 4 4240-01-267-8161 81361 5-1-1050-10
C-2 4 4240-01-268-0392 81361 5-1-1050-20
C-2 5 4820-01-260-8710 81361 5-1-1055
C-2 6 4820-01-226-7005 81361 5-1-1054
C-2 7 4730-01-391-8461 81361 5-1-1086
C-2 8 4820-01-260-8709 81361 5-1-1057
C-2 9 4241-01-260-8699 81361 5-1-1009
C-2 10 5365-01-260-8700 03038 5-1-1059
C-2 11 5965-01-260-8701 81361 5-1-1047
C-2 12 5330-01-260-8702 81361 5-1-1060
C-3 1 4240-01-415-4517 81361 5-1-1001-10
C-3 1 4240-01-415-4518 81361 5-1-1001-20
C-3 1 4240-01-416-0430 81361 5-1-1001-30
C-3 2 5965-01-414-2257 81361 5-1-3339
C-3 3 4240-01-260-8706 81361 5-1-1545-20
C-3 4 4240-01-260-8707 81361 5-1-1545-10
C-3 5 4240-01-399-3350 81361 5-1-2774
C-3 6 4240-01-361-1319 81361 5-3-1520
C-3 7 4240-00-377-9401 81349 MILB51170
C-3 8 4240-01-260-8697 81361 5-1-1003
C-3 9 4720-01-378-6479 81361 5-1-1963
C-3 10 4240-01-376-1382 81361 5-1-1971
C-3 11 4240-01-376-3152 81361 5-1-2701
C-3 12 4240-01-376-0471 81361 5-1-2707-1
C-3 12 4240-01-381-1568 81361 5-1-2707-2
C-3 13 4240-01-413-1540 81361 5-1-3321-10
C-3 13 4240-01-413-1543 81361 5-1-3321-20
I-4
TM 3-4240-346-20 & P
TM 09204A/09205A - 20&P/2
SECTION IV
CROSS-REFERENCE INDEXES
FIGURE AND ITEM NUMBER INDEX
FIG ITEM STOCK NUMBER CAGEC PART NUMBER
C-4 1 4820-01-260-8703 81361 5-1-1081
C-4 2 4240-01-260-8711 81361 5-1-1085
C-4 3 81361 5-1-2796
C-4 4 4240-01-267-8161 81361 5-1-1050-10
C-4 4 4240-01-268-0392 81361 5-1-1050-20
C-4 5 4820-01-260-8710 81361 5-1-1055
C-4 6 4820-01-226-7005 81361 5-1-1054
C-4 7 4730-01-391-8461 81361 5-1-1086
C-4 8 4820-01-260-8709 81361 5-1-1057
C-4 9 4240-01-260-8699 81361 5-1-1009
C-4 10 5365-01-260-8700 81361 5-1-1059
C-4 11 5965-01-260-8701 81361 5-1-1047
C-4 12 5330-01-260-8702 81361 5-1-1060
C-5 1 4730-01-392-2173 81361 5-1-1960-10
C-5 1 5330-01-231-3877 81361 5-1-1522
C-6 2 4240-01-260-8696 81361 5-1-1524
I-5 (I-6 blank)
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
APPENDIX D
EXPENDABLE AND DURABLE ITEMS LIST
SECTION I. INTRODUCTION
D-1. SCOPE
The expendable/durable supplies and materials list is identical for the M40A1 and the M42A2 masks. This appendix lists
expendable and durable items that you will need to operate and maintain the M42/M42A1/M42A2 Masks. This listing is for
informational purposes only and is not authority to requisition the listed items. These items are authorized to you by CTA
50-970, Expendable/Durable Items (except medical, Class V, repair parts, and heraldic items), or CTA 8-100, Army
Medical Department Expendable/Durable Items.
D-2. EXPLANATION OF COLUMNS.
a. Column 1-Item Number. This number is assigned to the entry in the listing and is referenced in the narrative
instructions to identify the item.,("Use tubing, item 5, app E").
b. Column 2-Level. This column identifies the lowest level of maintenance that requires the listed item (C-
Operator/Crew, O-Unit Maintenance, F- Direct Support Maintenance).
c. Column 3-National Stock Number. This is the National stock number assigned to the item which you can use to
requisition it.
d. Column 4-Description. Indicates the item name, description, (CAGEC) and part number. This provides the other
information you need to identify the item.
e. Column 5-Unit of Measure (U/M). This code shows the physical measurement or count of an item, such as gallon
(GL), each (EA), dozen (DZ), gross (GZ), etc. If the unit of measure differs from the unit of issue, requisition the lowest unit
of issue that will satisfy your requirements.
D-1
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
SECTION II. EXPENDABLE AND DURABLE ITEMS LIST
(1) (2) (3) (4) (5)
NATIONAL
ITEM STOCK
NUMBER LEVEL NUMBER DESCRIPTION U/M
1 O 6515-01-234-6838 APPLICATOR, DISPOSABLE: plastic EA
or wood, cotton tipped
(5L934) 362
2 C 7920-00-205-0565 BRUSH, DUSTING, LENS EA
(81348) H-B-1654
3 C 7920-00-461-0037 BRUSH, SCRUB: nylon bristle EA
(81348) H-B- 1490-6-P1
4 O 6665-00-978-5516 BULB, ASPIRATOR EA
(40912)B-H-5607
5 O 6810-00-242-4770 CALCIUM HYPOCHLORITE, TECHNICAL: LB
granular: 45 lb. bx. (12 ea 3-3/4 lb. bt.)
(81348)OC114
O 6810-00-255-0471 6 oz. BT OZ
O 6810-00-238-8115 5 lb. BT LB
6 O 6850-00-592-3283 CLEANING COMPOUND, OPTICAL LENS DZ
(04019) LENSWICK
7 C 8305-00-222-2423 CLOTH, CHEESECLOTH YD
(81348)CCC-C-440
8 O 8415-00-926-6696 GLOVES, CHEMICAL AND OIL PR
(81348) ZZ-G-381
9 C 6505-00-655-8366 ISOPROPYL RUBBING ALCOHOL: PT
bottle, plastic container
(56287) PUREPAC
10 O 8010-00-085-0559 LACQUER: No. 4 black, bushing 4.0 oz OZ
(133.4 g) bt
(19139)4
11 O 6810-00-123-7047 N-AMYL ACETATE, REAGENT: PT
clear flammable liquid
(81349) MIL-C-51130
D-2
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
SECTION II. EXPENDABLE AND DURABLE ITEMS LIST
(1) (2) (3) (4) (5)
NATIONAL
ITEM STOCK
NUMBER LEVEL NUMBER DESCRIPTION U/M
12 C 7240-01-094-4305 PAIL, UTILITY: plastic, snap-on lid, EA
5.00 gal.
(58536) A-A-332
13 O 5120-00-228-0730 SCREWDRIVER, JEWELER EA
(81348) GGG-S-1808 type 1
14 O 5110-00-293-3444 SHEARS, STRAIGHT TRIMMERS: 6 in. PR
(81348) GGG-S40278
15 C 8520-00-228-0598 SOAP, TOILET: nonmedicated, CL
liquid, type 1
(81348) P-S-624
16 O 6665-00-928-5731 TUBE, SMOKE EA
(40912) BH5645
17 O 8115-00-726-0673 BOX SHIPPING EA
(81348) PPP-B-640
18 O 8115-00-222-3715 CRATE, SHIPPING EA
(81336) D1152-1
19 O 8135-00-116-1443 CUSHIONING MATERIAL RO
(81349) MIL-P-26514
20 O 7510-00-266-5016 TAPE, PRESSURE SENSITIVE: 2" wide RO
(81348) PPP-T-60
D-3 (D-4 blank)
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
INDEX
SUBJECT PAGE
A
Adjusting Mask Assembly at Initial Fitting .................................................................................................................. 2-19
Adjusting Mask Assembly ................................................................................................................................... 2-21
Checking Mask Assembly for Fit ......................................................................................................................... 2-22
Putting on Mask Assembly .................................................................................................................................. 2-20
Airflow Deflector, Inlet Valve Disk, and Valve Body.................................................................................................... 2-59
Installation .......................................................................................................................................................... 2-61
Removal ............................................................................................................................................................. 2-59
C
Checking Drinking System for Proper Function.......................................................................................................... 2-28
Checking the Mask Assembly for Proper Function ..................................................................................................... 2-23
Testing Mask Assembly with a-Amyl Acetate....................................................................................................... 2-24
Testing Mask Assembly with M41 PATS (M40A1) ............................................................................................... 2-23
Testing Mask Assembly with M41 PATS (M42A2) ............................................................................................... 2-23
Checking for Leaks.................................................................................................................................................... 2-28
Clamp Cover............................................................................................................................................................. 2-75
Installation .......................................................................................................................................................... 2-75
Removal ............................................................................................................................................................. 2-75
Cleaning and Sanitizing............................................................................................................................................. 2-77
Cleaning Carrier (M40A1) ................................................................................................................................... 2-80
Cleaning Carrier (M42A2) .................................................................................................................................. 2-90
Cleaning Mask Assembly (M40A1)..................................................................................................................... 2-77
Cleaning Mask Assembly (M42A2)...................................................................................................................... 2-85
Sanitizing Mask Assembly (M40A1) .................................................................................................................... 2-81
Sanitizing Mask Assembly (M42A2 ) ................................................................................................................... 2-91
Common Tools and Equipment ................................................................................................................................. 2-3
Corrosion Prevention and Control (CPC) .................................................................................................................. 1-1
D
Destruction of Army Materiel to Prevent Enemy Use.................................................................................................. 1-1
Differences Between Models .................................................................................................................................... 1-10
E
(EIR), Reporting Equipment Improvement Recommendations.................................................................................... 1-1
Equipment Characteristics, Capabilities, and Features............................................................................................... 1-2
Equipment Data ........................................................................................................................................................ 1-11
Equipment/User Fitting Instructions ........................................................................................................................... 2-19
Expendable Durable Supplies and Materials List ....................................................................................................... D-1
F
Figure and Item Number Index ................................................................................................................................ I-4
H
Head Harness ........................................................................................................................................................... 2-57
Installation .......................................................................................................................................................... 2-57
Removal ............................................................................................................................................................. 2-57
How to Use This Manual ........................................................................................................................................... iii
Index 1
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
INDEX
SUBJECT PAGE
I
Identifying an Individual's Mask ................................................................................................................................. 2-18
Index (Chapter 2) ...................................................................................................................................................... 2-1
Internal Drink Tube.................................................................................................................................................... 2-54
Checking for Fit.................................................................................................................................................. 2-55
Installation .......................................................................................................................................................... 2-54
Removal ............................................................................................................................................................. 2-54
Internal Drink Tube Nipple......................................................................................................................................... 2-66
Verification.......................................................................................................................................................... 2-66
Installation .......................................................................................................................................................... 2-67
Removal ............................................................................................................................................................. 2-67
L
Left/Right Filter Canister/Hose Assembly Conversion ................................................................................................ 2-45
M
Maintenance Allocation Chart (MAC) (M40A1)........................................................................................................... B-3
Maintenance Allocation Chart (MAC) (M42A2)........................................................................................................... B-4
Maintenance Forms, Records, and Reports............................................................................................................... 1-1
Maintenance Procedures........................................................................................................................................... 2-53
N
National Stock Number Index ................................................................................................................................... I-1
Nosecup Valve Disks................................................................................................................................................. 2-58
Installation .......................................................................................................................................................... 2-58
Removal ............................................................................................................................................................. 2-58
O
Optical Insert Kit, Plastic............................................................................................................................................ 2-68
Adjustment.......................................................................................................................................................... 2-72
Installation .......................................................................................................................................................... 2-70
Removal ............................................................................................................................................................. 2-69
Optical Insert Kit, Wire............................................................................................................................................... 2-68
Installation .......................................................................................................................................................... 2-68
Removal ............................................................................................................................................................. 2-68
Outlet Valve Cover and Outlet Valve Disk.................................................................................................................. 2-63
Installation .......................................................................................................................................................... 2-64
Removal ............................................................................................................................................................. 2-63
P
Port Gasket............................................................................................................................................................... 2-76
Installation .......................................................................................................................................................... 2-76
Removal ............................................................................................................................................................. 2-76
Preparation for Storage or Shipment ......................................................................................................................... 2-95
Preventative Maintenance Checks and Services (PMCS) .......................................................................................... 2-39
Principles of Operation .............................................................................................................................................. 1-12
Putting on Mask Assembly ........................................................................................................................................ 2-20
Q
Quick Disconnect Coupling, External Drink Tube....................................................................................................... 2-56
Installation .......................................................................................................................................................... 2-56
Removal ............................................................................................................................................................. 2-56
Index 2
TM 3-4240-346-20 & P
TM 09204A/09205A-20 & P/2
INDEX
SUBJECT PAGE
R
References................................................................................................................................................................ A-1
Repair Parts and Special Tools List (RPSTL)............................................................................................................. C-1
Repair Parts, Special Tools, TMDE and Support Equipment...................................................................................... 2-3
Reporting Equipment Improvement Recommendations (EIR) .................................................................................... 1-1
Reporting Errors and Recommending Improvements................................................................................................. i
S
Sanitizing M40A1 ...................................................................................................................................................... 2-81
Sanitizing M42A2 ...................................................................................................................................................... 2-91
Service Upon Receipt................................................................................................................................................ 2-3
Service Upon Receipt of Materiel .............................................................................................................................. 2-3
Side Voicemitter, Voicemitter Retainer, and Gasket................................................................................................... 2-65
Installation .......................................................................................................................................................... 2-65
Removal ............................................................................................................................................................. 2-65
Storage or Shipment, Preparation for ........................................................................................................................ 2-95
Supplies and Materials List, Expendable/Durable ...................................................................................................... D-1
Part Number Index .................................................................................................................................................... I-2
Symptom Index ......................................................................................................................................................... 2-29
T
Table of Contents...................................................................................................................................................... ii
Tools and Equipment, Common ................................................................................................................................ 2-3
Tool and Test Equipment Requirements.................................................................................................................... 2-3
Troubleshooting ........................................................................................................................................................ 2-29
U
Unit Maintenance Repair Parts and Special Tools List ............................................................................................... C-1
Unit Maintenance Instructions (See Individual Procedure) ......................................................................................... 2-53
V
Voicemitter, Side, Voicemitter Retainer and Gasket................................................................................................... 2-65
Installation .......................................................................................................................................................... 2-65
Removal ............................................................................................................................................................. 2-65
Index 3 (Index 4 blank)
By Order of the Secretary of the Army:
DENNIS J. REIMER
Official: General United States Army
Chief of Staff
JOEL B. HUDSON
Administrative Assistant to the
Secretary of the Army
05239
DISTRIBUTION:
To be distributed in accordance with the Initial Distribution Number (IDN) 280848 , requirements for TM
3-4240-346-20&P
M. K. HAYDEN
Colonel, USMC
Director, Program Support
Marine Corps Systems Command
PIN: 076904-000