STEERING SYSTEM

H8.00-12.00XM (H170-280HD) [F007, G007];

H13.00-16.00XM (H300-360HD) [E019, F019];

H10.00-12.00XM-12EC (H360HD-EC) [E019, F019]

PART NO. 1494140

1600 SRM 936

SAFETY PRECAUTIONS

MAINTENANCE AND REPAIR

• When lifting parts or assemblies, make sure all slings, chains, or cables are correctly

fastened, and that the load being lifted is balanced. Make sure the crane, cables, and
chains have the capacity to support the weight of the load.

• Do not lift heavy parts by hand, use a lifting mechanism.

• Wear safety glasses.

• DISCONNECT THE BATTERY CONNECTOR before doing any maintenance or repair

on electric lift trucks.

• Disconnect the battery ground cable on internal combustion lift trucks.

• Always use correct blocks to prevent the unit from rolling or falling. See HOW TO PUT

THE LIFT TRUCK ON BLOCKS in the Operating Manual or the Periodic Mainte-
nance section.

• Keep the unit clean and the working area clean and orderly.

• Use the correct tools for the job.

• Keep the tools clean and in good condition.

• Always use HYSTER APPROVED parts when making repairs. Replacement parts

must meet or exceed the specifications of the original equipment manufacturer.

• Make sure all nuts, bolts, snap rings, and other fastening devices are removed before

using force to remove parts.

• Always fasten a DO NOT OPERATE tag to the controls of the unit when making repairs,

or if the unit needs repairs.

• Be sure to follow the WARNING and CAUTION notes in the instructions.

• Gasoline, Liquid Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Diesel fuel

are flammable. Be sure to follow the necessary safety precautions when handling these
fuels and when working on these fuel systems.

• Batteries generate flammable gas when they are being charged. Keep fire and sparks

away from the area. Make sure the area is well ventilated.

NOTE:

The following symbols and words indicate safety information in this

manual:

WARNING

Indicates a condition that can cause immediate death or injury!

CAUTION

Indicates a condition that can cause property damage!

Steering System

Table of Contents

TABLE OF CONTENTS

General ...............................................................................................................................................................

Description .........................................................................................................................................................

Steering Wheel and Column Assembly.............................................................................................................

General ...........................................................................................................................................................

Steering Wheel and Horn..............................................................................................................................

Remove.......................................................................................................................................................

Install .........................................................................................................................................................

Steering Control Unit Repair ............................................................................................................................

General ...........................................................................................................................................................

Description .....................................................................................................................................................

Operation .......................................................................................................................................................

Remove ...........................................................................................................................................................

Disassemble ...................................................................................................................................................

Clean ..............................................................................................................................................................

Assemble and Install .....................................................................................................................................

Steering System Air Removal ...........................................................................................................................

Steering Relief Pressure Check.........................................................................................................................

Troubleshooting..................................................................................................................................................

This section is for the following models:

H8.00-12.00XM (H170-280HD) [F007, G007];

H13.00-16.00XM (H300-360HD) [E019, F019];

H10.00-12.00XM-12EC (H360HD-EC) [E019, F019]

"THE

QUALITY

KEEPERS"

HYSTER

APPROVED

PARTS

1600 SRM 936

Description

General

This section has the description and repair proce-
dures for the parts of the steering system. Descrip-
tion and repair information is given for the steer-
ing wheel and column assembly, the steering control
unit, and the priority valve. Repair information for

the parts of the steering axle are in the section Steer-
ing Axle 1600 SRM 326. Repair information for the
steering hydraulic pump is in the section Hydraulic
System 1900 SRM 938.

Description

These lift trucks use a hydraulic steering system.
See Figure 1 and Figure 2. The hydraulic system has
a tandem, gear-type pump. The two sections have a
common inlet and separate outlets. The small sec-
tion of the pump supplies oil to the steering system.
When the steering wheel is not turned, most of the
hydraulic oil from the small pump goes to the main

control valve via the priority valve for the lift, tilt,
and auxiliary circuits.

When the engine is not running, a check valve closes
and permits the steering control unit to control the
steering system. The lift truck is difficult to steer
when the steering pump is not operating, but the
steering control unit can make steering possible.

STEERING CYLINDER

MANIFOLD BLOCK

STEERING PRIORITY VALVE

HYDRAULIC TANK

PILOT VALVE

HYDRAULIC PUMP

Figure 1. Steering System Diagram

Description

1600 SRM 936

HYDRAULIC TANK

SMALL HYDRAULIC PUMP

LARGE HYDRAULIC PUMP

STEERING LINE RELIEF VALVE

STEERING PRIORITY VALVE

STEERING CONTROL UNIT

STEERING CYLINDER

TO MAIN CONTROL VALVE

TO PILOT BLOCK VALVE

Figure 2. Steering System Schematic Diagram

1600 SRM 936

Steering Wheel and Column Assembly

GENERAL

The steering column, located in the cab, is mounted
to a support bracket and the floor of the cab. See
Figure 3. The steering column is fitted to the steering
control unit through the cab floor. The steering wheel
is held on the splines of the steering column with a
large nut. The steering control unit has splines that
engage with the lower end of the steering column.
The steering control unit is fastened to the underside
of the cab floor with four bolts.

STEERING WHEEL AND HORN

This procedure describes the replacement of the
steering wheel and horn actuator assembly. Disas-
semble the parts as required to make repairs.

Remove

WARNING

To prevent electrical arcs when removing
cover, disconnect negative battery cable.

Disconnect battery. Remove horn button from
steering wheel. See Figure 3.

Remove electrical wire from horn button. Re-
move large nut and pull steering wheel from
steering shaft.

See Steering Control Unit Repair for more disas-
sembly procedures.

Install

Install steering wheel and large nut onto steering
shaft. See Figure 3. Tighten nut to 35 to 45 N•m
(26 to 33 lbf ft).

Attach electrical wire from horn switch to horn
button. Install horn button.

Steering Wheel and Column Assembly

1600 SRM 936

SCREW

WASHER

SCREW

WASHER

SOCKET

HORN BUTTON

SPINNER KNOB

STEERING WHEEL

HARNESS

10. UPPER STEERING COLUMN

COVER

11. LH STEERING COVER

COLUMN

12. RH STEERING COVER

COLUMN

13. LH STEERING COVER

COLUMN

14. RH STEERING COVER

COLUMN

15. COLUMN ASSEMBLY -

STEERING

16. BOOT
17. LIGHT

Figure 3. Steering Wheel and Steering Column Assembly

1600 SRM 936

Steering Control Unit Repair

GENERAL

This section has a description section, an operation
section, and repair procedures for the steering con-
trol unit.

DESCRIPTION

The steering control unit is a hydrostatic unit con-
trolled by the steering wheel. See Figure 4. It is
mounted on the underside of the cab floor. The steer-
ing control unit has a shaft assembly, control section,
and a metering section. The hydraulic hoses for the
steering system are fastened to a manifold block.

Turning the steering wheel actuates three main
parts of the steering control unit: (1) the spool for
the control section, (2) the sleeve for the control
section, and (3) the rotor in the metering section.
When the steering wheel is not moving, the spool
and sleeve are held in the neutral (center) position
by springs. During this time, oil flows freely through
the steering control unit. The oil does not flow to the
steering cylinder.

OPERATION

As the steering wheel is turned, the spool just begins
to rotate. See Figure 4. The springs try to move the
sleeve to keep the neutral position between the spool
and sleeve. However, the force necessary to turn the
rotor is greater than the pressure of the springs. The
springs begin to bend, letting the spool move a small
amount within the sleeve. The spool stops moving
when it touches the center pin. In this position, the
holes in the sleeve and the spool are aligned. Oil
coming into the control unit flows to the metering
section.

More rotation of the steering wheel causes the spool
to rotate the pin. This action causes the rotation of
the sleeve and the rotor in the metering section. The
oil then flows to one side of the steering cylinder. Oil
from the other side of the steering cylinder flows back
to the control section of the steering control unit.

When the steering wheel stops moving, the metering
action in the metering section also stops. The neutral
position springs return the sleeve to the neutral po-
sition. When this action occurs, the pressure stays in
the steering cylinder to keep the tires in position. Oil

from pump flows through the steering control unit
to the main control valve. To return the tires to the
straight position, the steering wheel must be rotated
in the opposite direction. The steering control unit
will operate as described, but all parts will rotate in
the opposite direction.

CONTROL
SECTION

METERING
SECTION

CHECK BALL
(MANUAL
OPERATION)

SLEEVE

NEUTRAL
POSITION
SPRINGS

SPOOL

Figure 4. Steering Control Unit

The steering control unit has a pilot-operated relief
valve and an additional port for a pilot line. A prior-
ity valve is also used in the system and is connected
to the hydraulic pump.

The demand for steering is sensed at the LS port in
the steering control unit. The pilot line from the LS
port is connected to the priority valve. The priority
valve has a pilot-operated spool. While steering, a
spring and pilot pressure from the load sensing (LS)
line hold the spool open for steering. When there is
no pressure in the LS line (no steering), pilot pres-
sure from the hydraulic pump shifts the spool.

Steering Control Unit Repair

1600 SRM 936

REMOVE

Raise operator’s cab. See the section Operators
Cab for your lift truck.

Put tags on hydraulic lines at manifold block.
Disconnect hydraulic lines and put caps on open-
ings.

Remove four capscrews that fasten steering con-
trol unit to underside of cab floor and remove
steering control unit from end of steering column.
See Figure 3.

DISASSEMBLE

NOTE:

Tag location of all component parts to help in assembly of control unit.

NOTE:

Do not disassemble manifold block. Check valve cannot be removed. Relief valve is set by manufacturer.

STEP 1.

Put control unit in a vise with soft jaws. Make an
identification mark on length of control unit. Remove
manifold block.

STEERING CONTROL UNIT

VISE

STEP 2.

Remove cover on bottom of steering control unit.

O-RING

COVER

CAPSCREW

1600 SRM 936

Steering Control Unit Repair

STEP 3.

Remove spacer, stator, rotor, and port plate. Put a
mark on stator so that same side is toward body of
control unit. Remove O-rings. Remove center shaft.

O-RING

CENTER SHAFT

PORT PLATE

STATOR

ROTOR

SPACER

STEP 4.

Remove retainer for check ball. Remove check ball.

RETAINER

Steering Control Unit Repair

1600 SRM 936

STEP 5.

Remove spool and sleeve assembly. Remove thrust bearing assembly from spool. Push center pin from sleeve.
Carefully remove spool from sleeve. (Rotate spool slowly during removal.) Remove ring from sleeve. Remove
neutral position springs from spool.

SPOOL AND SLEEVE ASSEMBLY

RING

SPOOL

SLEEVE

NEUTRAL POSITION SPRINGS

CENTER PIN

THRUST BEARING

THRUST WASHER

STEP 6.

Remove relief valve assembly and dust seal from
housing. Do not disassemble relief valve cartridge.

DUST SEAL

RELIEF VALVE ASSEMBLY

HOUSING

1600 SRM 936

Steering Control Unit Repair

CLEAN

WARNING

Cleaning solvents can be flammable and toxic
and can cause skin irritation.

When using

cleaning solvents, always follow the solvent

manufacturer’s recommended safety precau-
tions.

Clean all parts in solvent. Dry parts with compressed
air. Do not dry parts with a cloth. Make sure all
surfaces are free of scratches and sharp edges.

ASSEMBLE AND INSTALL

NOTE:

Use new seals, O-rings, and neutral position springs during assembly. Lubricate all parts with clean

hydraulic oil.

STEP 1.

Carefully assemble spool and sleeve. Make sure spool
rotates freely in sleeve. Make sure alignment marks
are aligned.

SPOOL

SLEEVE

Steering Control Unit Repair

1600 SRM 936

STEP 2.

Assemble neutral position springs, then push them
into position in spool. Make sure flat springs are
installed to outside of curved springs. Install center
pin.

Install ring on sleeve (over neutral position

springs). Ring must turn freely on sleeve.

SPOOL

NEUTRAL POSITION SPRINGS (FLAT)

NEUTRAL POSITION SPRINGS (CURVED)

CENTER PIN

RING

1600 SRM 936

Steering Control Unit Repair

STEP 3.

Put spool on workbench; then put housing onto spool
as shown. Install guide ring with O-ring on end of
spool. Put a large thrust washer (see STEP 4) on top
of guide ring and O-ring assembly. Use socket or tube
to push on washer and install O-ring and guide ring
in housing. Carefully remove washer, tube, and spool
from housing.

HOUSING

WASHER

O-RING

GUIDE RING

SPOOL

TUBE

STEP 4.

Install thrust washers and thrust bearing on spool.
Make sure chamfer on inner thrust washer is next to
sleeve.

THRUST BEARING

THRUST WASHER

SPOOL

SLEEVE

Steering Control Unit Repair

1600 SRM 936

STEP 5.

Install spool and sleeve assembly in housing. Care-
fully rotate spool and sleeve assembly during in-
stallation to make sure spool fits correctly in seal
installed in STEP 3. Make sure center pin on spool
and sleeve assembly is horizontal (parallel to surface
with ports).

HOUSING

SPOOL AND SLEEVE ASSEMBLY

STEP 6.

Install check ball and retainer. Make sure retainer
is even with or below surface of housing. Lubricate
O-ring and install O-ring and port plate. Align holes
in port plate with holes in housing.

CHECK BALL RETAINER

O-RING

PORT PLATE

HOUSING

1600 SRM 936

Steering Control Unit Repair

STEP 7.

Install center shaft so that it engages with center pin in spool and sleeve assembly. Make sure center pin is
still parallel to surface with ports. Install rotor on center shaft. Make sure that a valley in rotor aligns with
slot (center pin) in center shaft. Install O-ring and stator. Make sure to align marks made during disassembly.

CENTER SHAFT

CENTER PIN

ROTOR

STATOR

O-RING

Steering Control Unit Repair

1600 SRM 936

STEP 8.

Install spacer. Install O-ring and cover. Tighten capscrews for cover, in sequence shown, to 17 N•m (150 lbf in),
then tighten them to 30 N•m (265 lbf in). Make sure capscrew with pin fits in hole for check ball.

CHECK BALL

RETAINER

CAPSCREW

O-RING

COVER

SPACER

STEP 9.

Install dust seal in housing. When used, install relief
valve assembly.

DUST SEAL

RELIEF VALVE ASSEMBLY

1600 SRM 936

Steering System Air Removal

STEP 10.

Install manifold block and O-rings on steering con-
trol unit. Tighten capscrews for manifold block to
40 N•m (30 lbf ft).

MANIFOLD BLOCK

O-RING

STEERING CONTROL UNIT

WARNING

After making repairs, do not extend hands or arms through steering wheel. If control unit was not
assembled correctly or lines not connected correctly, steering wheel can rotate with a strong force
and cause injury. If this action occurs, disassemble control unit or check lines to correct problem.

STEP 11.

See Figure 3. Install steering column and steering control unit on brackets. Connect hydraulic lines at manifold
block. Start engine and operate steering wheel. Check for correct operation.

Steering System Air Removal

Air can enter the system when a hydraulic line is
disconnected. If the operation is rough, start engine
and rotate steering wheel stop-to-stop several times

in each direction. Air will be removed without dis-
connecting any lines. If the operation is still rough,
air can be entering the system at a loose fitting.

Troubleshooting

1600 SRM 936

Steering Relief Pressure Check

NOTE:

The relief valve is in the steering control unit.

The relief pressure is set at the factory.

Tilt operator’s cab. See the section Operator’s
Cab for your lift truck.

Connect 0 to 20 MPa (0 to 3000 psi) gauge to test
port. See Figure 5.

Start engine.

Operate hydraulic system until

temperature of hydraulic oil is 55 to 65 C (130 to
150 F). Run engine at approximately 2500 rpm
when checking pressure.

Steer in one direction until wheels will not turn
further. Keep steering wheel fully turned and
read gauge. Correct relief pressure is 16.5 MPa
(2400 psi).

If relief pressure is not correct, remove plug and
adjust pressure by turning screw.

WARNING

The adjustment screw compresses a spring.
Use caution and wear eye protection when
adjusting relief valve.

If relief pressure is not correctly set, remove
plug and adjust pressure by turning adjustment

screw. If you cannot correctly adjust relief pres-
sure, replace parts of relief valve.

When checks are complete, remove gauge and in-
stall cap on fitting.

STEERING RELIEF VALVE PLUG

MANIFOLD BLOCK

Figure 5. Manifold Block, Steering Control

Unit

Troubleshooting

PROBLEM

POSSIBLE CAUSE

PROCEDURE OR ACTION

No action

when

steering

wheel is turned.

No oil or not enough oil in hydraulic
tank.

Fill tank to correct level.

Lines are loose at control unit or
manifold block.

Tighten fittings.

Sleeve and spool in control unit will
not move.

Repair steering control unit.

Steering cylinder leaks.

Repair steering cylinder.

Spacer for center pin is not installed.

Assemble steering control unit cor-
rectly.

1600 SRM 936

Troubleshooting

PROBLEM

POSSIBLE CAUSE

PROCEDURE OR ACTION

Lift

truck

steers

slowly.

Steering wheel is hard to
turn.

Oil level is low. There is no oil in
tank.

Fill tank to correct level.

Lines to control unit are damaged.

Repair oil lines.

Sleeve and spool in control unit are
worn.

Repair steering control unit.

Parts of metering section are worn.

Repair steering control unit.

Check valve in control unit does not
open.

Clean or repair steering control unit.

Check valve or relief valve in man-
ifold block is damaged or is not ad-
justed correctly.

Clean or replace manifold block.

Priority valve is not operating cor-
rectly.

Clean or repair priority valve.

Steering relief pressure is too low.

Adjust relief pressure.

Engine idle speed is too low.

Adjust idle speed to specifications.

Steering wheel turns tires in
wrong direction.

Lines at control unit are not correctly
connected.

Connect lines correctly.

Tires continue to turn after
steering wheel stops.

Neutral position springs are broken.

Repair steering control unit.

Sleeve or spool has damage.

Repair steering control unit.

Steering wheel kicks back in
both directions.

Center shaft is not correctly aligned
with metering section.

Assemble steering control unit cor-
rectly.

NOTES

____________________________________________________________

TECHNICAL PUBLICATIONS

1600 SRM 936

9/03 (2/01)(1/95) Printed in United Kingdom

Document Outline

Wyszukiwarka

Podobne podstrony:

więcej podobnych podstron

1494140 1600SRM0936 (09 2003) UK EN

Document Outline