E-E-40 RO3
PARTS-SERVICE
Date: Jan. 20, 1986
Model: S/H25-35XL,
GRAM
S/H40-60XL
Fuel Page 1 of 2
This revision
reports effective
SUBJECT: L.P. VACUUM LOCK-OFF VACUUM SOURCE serial numbers.
The vacuum source for the vacuum operated LPG fuel lock-off valve has been relocated from the engine intake
manifold to the carburetor. This reduces the possibility of engine vacuum pulsations causing lock-off valve
deterioration.
CONVERSION:
To relocate the vacuum source the following steps should be followed:
1. Remove and discard the vacuum hose between the manifold and lock-off valve.
2. Remove and discard the vacuum fitting on the manifold and replace wi th 287805 plug and 222086
gasket.
3. As shown in Figure I remove screw from carburetor and install vacuum fitting 372115 in its place.
4. Per Chart I install proper length of 5/32 I.D. vacuum hose between carburetor vacuum port and vacuum
lock-off valve. Secure hose to vacuum fittings with two clamps 168718.
5. Tie hose back as necessary with nylon straps 137852.
INTERCHANGEABILITY:
The parts are directly interchangeable by following these instructions.
PARTS STOCK:
Not affected. Carburetors did not change part numbers but new orders for carburetors will have vacuum fitting
372115 installed.
EFFECTIVE SERIAL NUMBERS:
Trucks after these serial numbers have already been modified per this gram.
S25-35XL B10B-3198F
H25-35XL C1B-3266F
H40-60XL A177B-10812F
S40-60XL A187V-2915F
A187T-1501E
We reserve the right to make changes in design or add improvements without incur-
ring the obligation to make such changes in equipment previously manufactured.
H6030
E-E-40 R03
Page 2 of 2
FUEL INLET
IDLE MIXTURE ADJUSTMENT
REMOVE THIS SCREW
INSTALL FITTING 372115
VACUUM ADVANCE FTG TO DISTRIBUTER
FIGURE I CARBURETOR VACUUM PORT LOCATION
Model Inches of Bulk Hose 181761
S25-35XL 14-3/4
H25-35XL 14-3/4
S40-60XL 29
H40-60XL 31-3/4
CHART I RECOMMENDED VACUUM HOSE LENGTH