TM 5-6115-400-12
transfer pump and is then forced through fuel filter F2 to
Caution: Do not use starting motor
the fuel injection pump.
continuously for more than 30
c. In the high pressure system, the fuel injection
seconds. After 30 seconds of use,
pump picks up fuel from the gallery, meters and forces
pause two minutes to allow motor to
the fuel, under extremely high pressure, to the fuel
cool.
injection nozzles. The nozzles spray the fuel into the
engine combustion chambers. The fuel injection lines
(6) Tighten vent screw of second stage filter
are seamless steel tubing and each line is the same
F2 while continuing to rotate engine.
length. These lines being of equal length assures
proper timing and the proper amount of fuel to each
b. Bleeding Fuel Injection Pump Gallery. To bleed
injection nozzle.
the pump gallery, disconnect the fuel line from the
overflow valve (fig. 3-20) and rotate engine. Continue
3-30. Fuel Strainer and Filters
until fuel oil free of bubbles flows from over)flow valve.
Reconnect fuel line to overflow valve (fig. 3-20).
a. General. The fuel strainer and filter head (fig.
c. Venting High Pressure System.
3-18) is a manifold used to collect and distribute fuel;
(1) The high pressure fuel system is usually
the head also serves as a holder for the F1 and F2
self-venting due to the fact that any air
elements and shells. The head for filter F3 is illustrated
trapped by the fuel injection pump
in figures 3-18(2) and 3-5(2).
Inspect heads for
plungers is forced out through the fuel
cleanliness at time of changing filter elements.
injection nozzles and into the engine
b. Filter and Strainer Service. Open the drain cock
combustion chambers. However, in the
in the bottom of each shell before start of daily
event the fuel lines have been removed,
operations in warm weather or shortly after the end of
the engine has run out of fuel, or the
daily operations in freezing weather. Allow any water or
engine has not been operated for some
sediment to drain. Close the drain cocks as soon as
time, venting of the high pressure system
clean fuel runs out. Remove and discard the filter
may be necessary to facilitate engine
elements F2 and F3 and install new elements after
starting.
every 500 hours of operation.
Clean F1 strainer
(2) Vent the high pressure fuel system as
element every 500 hours. Clogged fuel filters are
follows:
usually indicated by irregular engine performance. Vent
(a) Loosen connector nut attaching the
fuel system after replacing filter elements and cleaning
upper end of each fuel injection line
strainer element.
to its corresponding fuel line
connector in the rocker cover
3-31. Venting Fuel System
housing.
(b) Crank engine with the starter until
a. Day
Tank to Fuel Injection Pump. (figs. 3-17
fuel flows from ends of all fuel
and 3-18).
injection lines. Tighten fuel line
(1)
Close DC control circuit breaker.
connector nuts.
(2)
Place engine switch in RUN position.
Caution: Do not use starting
(3)
Place protection bypass switch in ON
motor continuously for more
position.
than 30 seconds.
After 30
(4) Loosen second stage fuel filter F2 vent
seconds of use pause two
screw.
minutes to allow motor to cool.
(5) Push starter switch to rotate engine until a
full stream of fuel flows from around the
3-32. Fuel Injection Pump
vent sow free of bubbles.
a. Removal. (Refer to fig. 3-19 and 3-20.)
(1) Remove governor actuator with hoses
attached.
3-25