be individually removed while the pump housing is
housing. The fuel injection pump housing an(d governor
installed on the accessory drive housing. The transfer
may be removed as a unit, or the governor may be
pump forces fuel through a filter, into the pump housing
removed alone (para 3-10).
inlet passage thence to each pump as required. The
amount of fuel pumped per stroke is varied by turning the
3-17. Fuel Injection Pump for Engine Model 687C-18-
plunger in the barrel. Plunger is turned by governor
ES
action on fuel rack which engages gear segment on
bottom of plunger. As the cam lobe puts pressure on
a. Removal and Installation.
plunger, plunger inlet passage moves past pump inlet
passage, and the proper amount of fuel enters pump.
(1) Remove nut (27, fig. 3-18) and disconnect
As pressure reaches 400-800 psi the check valve opens
ground wire (22) from fuel injection pump (10).
to allow fuel to enter the ejection line, thence to fuel
(2) Remove all external fuel and oil lines from
injection valve in combustion chamber. Camshaft is
fuel pump and drive mechanism (TM 5-3810-201-12).
located in lower section of fuel pump plungers and is
(3) Disconnect governor control linkage (TM
driven by an off-center tang on end of accessory drive
5-3810-201-12).
shaft. This camshaft determines vertical movement of
(4) Remove timing hole cover from fuel
fuel pump plungers and also drives the governor. The
camshaft is splash lubricated by oil from governor
1
Shutoff shaft
9
Housing timing mark
2
Shutoff cam
10
Cam
3
Washer
11
Spring
4
Guide stud
12
Spring
5
Metering valve
13
Governor arm
6
Throttle shaft lever
14
Housing
7
Cam timing mark
15
Governor control line
8
Governor weight timing mark
Figure 3-19. Shutoff cam, removal and installation.
AGO 20051A
3-28
