Chevrolet 70 1969 Series, Shop Manual

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ENGINE FUEL SYSTEM 6M -29
Figure 17—Limiting Speed Governor and Drive
under "Checking Fuel Pump." Substitute another
fuel pump that is known to be in good condition and
again check the flow. Follow "Removal" and "In­
stallation" instructions given later in this section.
Figure 18— Limiting Speed Governor Mounting
d. When changing a fuel pump, clean all fuel
line fittings with compressed air and be sure all
fuel line connections are tight.
Checking Fuel Pump
If the fuel pump fails to function satisfactorily,
check for broken pump shaft, or dirt in relief valve,
before removing the pump from the engine:
1. Insert the end of a wire through one of the
pump body drain holes, then crank the engine m o­
mentarily and see if wire vibrates. Vibration will
be felt if pump shaft rotates.
2. Without removing the pump from the engine,
unscrew valve screw (fig. 16), then remove spring,
pin and valve. Wash parts and blow out valve cavity
with compressed air. Install valve parts.
F U E L PUMP R E M O V A L
1. Turn steering wheel of vehicle to extreme
left position. Fuel pump is accessible from behind
right front wheel.
2. Disconnect fuel tubes from inlet and outlet
openings of the fuel pump.
3. Disconnect drain line from fuel pump, if
used.
4. Unscrew three pump attaching bolts and
washers and withdraw pump.
5. Check drive coupling and if broken, replace.
F U E L PUM P IN S T A L L A T IO N
1. Affix a new gasket to pump body and locate
pump drive coupling over square end of fuel pump
drive shaft.
2. Install fuel pump on engine and secure with
three bolt and washer assemblies.
3. Connect inlet and outlet fuel lines to the fuel
pump.
4. Connect drain tube, if used, to pump body.
G O VERN O R
Engines requiring a minimum and maximum
speed control, together with manually controlled
intermediate speeds, are equipped with a limiting
speed mechanical governor, such as that used on
the 6V-53 engine.
The limiting speed mechanical governor, il­
lustrated in figure 17, performs the following
functions:
1. Controls the engine idle speed.
2. Limits the maximum operating speed of the
engine.
The governor assembly number, type, and idle
speed range are stamped on the name plate attach­
ed to the governor housing. The letters D .W .- L.S.
stamped on the 6V-53 governor name plate denote
a double-weight limiting speed governor.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L