TM 5-3805-280-24-2
Fuel System Operation and Tests
CHECK FUEL SUPPLY PUMP OPERATION--
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43
IN-LINE INJECTION PUMP
NOTE: The following test procedure can best be
performed under moderate air temperature
conditions to reduce electrical loads when
cranking the engine is required.
Test fuel supply pump and hand primer for leaks:
1. Make a preliminary inspection of supply pump (A).
Thoroughly clean area around pump. All connections
must be tight and not leaking.
A--Supply Pump
B--Hand Primer
2. Start engine and bring to operating temperature. Shut
off engine.
NOTE: If fuel leaks around hand primer (B) that is
screwed down tight when engine is running,
replace the hand primer.
3. Check operation of hand primer. With engine shut off,
unscrew knob and operate hand primer through
several strokes. Moderate to heavy leakage of fuel
between plunger and barrel indicates seal is defective.
Replace hand primer.
NOTE: Appearance of a slight quantity of fuel around the
plunger is normal.
IMPORTANT: Be sure hand primer is seated all the
way down in barrel before tightening to
prevent internal thread damage.
4. Tighten hand primer knob, but do not overtighten. If
knob will not tighten (indicating internal thread
damage), replace hand primer.
Test operation of suction side of pump:
1. Disconnect suction and discharge lines at pump.
2. Drain all fuel from pump by operating hand primer.
Then reconnect suction line to pump.
Continued on next page
RG,115,JW7702 1924NOV971/3
13-570
