TRUCK SERVICE MANUAL
FUEL SYSTEM
Table 5-1: Current PT (type G) Governor Plungers
Note: The chamfer on small diameter of thrust washer is
Code
Red
provided as a relief for fillets of plunger driver.
Size 0
4. If It is necessary to remove stop sleeve, press stop
Part No.
182530
sleeve off shaft.
4. Place governor barrel In housing bore with
Assembly
chamfered end first and location pin hole on bottom side,
1. If stop sleeve was removed, press stop sleeve on
lining up scribe marks, then press barrel In housing with
plunger with notched end going on plunger first (notches
arbor press until It bottoms against spring pack housing.
toward governor barrel).
This is Important to align barrel retaining pin holes.
2. Assemble plunger driver through thrust washer and
5. Select a new Class 2 (green color code) plunger and
drive into plunger. Driver must have interference fit In
attempt to fit it in barrel, if plunger enters, try a Class 3
plunger.
(yellow). Keep trying larger sizes until one will not enter
barrel, then select plunger two sizes smaller than last
Note: The plunger has a lubrite finish. Protect it by
plunger which did enter for use. Plunger must drop into
bore of its own weight. Remark governor barrel with
laying the plunger on a copper jawed vise or V-block to
class size of plunger used. See Tables 51 or 52 for
prevent damage to the finish when installing pin.
class sizes and color codes.
3. Drive retainer pin through the plunger and plunger
6. Install spring dowel into bottom of barrel with ST-853
driver.
driver with slot of pin to front of housing.
Note: The chamfered side of thrust washer must be
installed next to driver. There must be at least 0.002 to
0.005 inch [0.05 to 0.13 mm] clearance between washer
face and driver so washer will 'float."
4. Install torque spring and shims as required, put the
small end of the spring on the shoulder end of the
plunger with a twisting motion to avoid distorting the
spring.
5. If torque spring is replaced with new one, select from
specification sheets pertinent to the fuel pump being
rebuilt, see fuel pump calibration data In Bulletin No.
3379068, 3379077 or 983533, "PT (type G) Fuel Pump
Calibration," and Table 53 following.
Fig, 5-23, F5139. Removing torque spring
6. One type of plunger failure is caused by excessive
Governor Plunger
heat from contact of the stop collar and sleeve during
long periods of overspeeding. Plunger stop collars
1. If necessary, remove torque spring (torque spring
machined from glass filled teflon eliminate this type of
used on PT (type G) governor plungers only) by twisting
failure.
spring off shoulder. Do not use a straight pull which will
stretch spring beyond its elastic limit so it has to be
Because of the large outside diameter of the teflon stop
replaced. Fig. 5-23.
collar it is Impossible to use a torque control spring if it is
2. If governor plunger outside diameter is worn, replace
required, therefore, the teflon stop collar is to be used
with new plunger of same class size as etched on barrel
only In PTG. fuel pumps that do not require a torque
face. See "Governor Barrel and Plunger"
control
3. If only thrust washer is worn, drive retainer pin from
plunger and pull governor plunger drive from plunger.
Table 5-3: Torque Springs and Specifications
Part
Color
Wire Dia.
Number
Pounds
Inches [mm]
Free Length
Number
Code
Inches [mm]
Coils
Load [kg]
@ Length
Inches [mm]
138782
Red/Blue
.047 [1.19]
5.2
5.40/5.76 [2.5/2.6]
@ .340 [8.64J
.640/.660 [16.26/16.76]
501
