TM5-6115-585-34
NAVFAC P-8-623-34
TO-35C2-3-455-2
TM-05684C/05685B-34
CHAPTER 4
MAINTENANCE OF FUEL SYSTEM
Section I. DESCRIPTION AND FUNCTION
4-1. GENERAL.
The engine fuel system consists of two pressure system; the
low pressure system and the high pressure system. In the low
pressure system, a fuel pump may draw fuel from an external
source to till set tank or set tank may be filled manually. If an
external fuel source is selected, a float valve assembly in the
set tank maintains the fuel level in the tank. Two other fuel
pumps (in series) draw fuel from the set tank and force the
fuel through a primary strainer, two secondary filters, and a
check valve assembly, to the injection pump. In the high
pressure system, the fuel injection pump forces the fuel,
under high pressure, to the fuel injection nozzles. The injec-
tion nozzles provide fuel to each combustion chamber of the
engine. A small quantity of unused fuel is returned from the
injectors and injector pump to the fuel tank. A cam and gear
on the camshaft drives the fuel injection pump. The gear
drives the pump face gear, providing fuel distribution to
each cylinder in the proper order. The cam operates the
pump plunger, pressurizing fuel to the nozzles. A control
sleeve meters fuel by controlling the length of time the
plunger spill port is closed, maintaining pressure, and there-
fore, the amount of fuel delivered in each stroke. The pintle
type injection nozzles are conventional inward opening with
adjustable opening pressure. They are factory adjusted to
open at 1900 to 1950 psi.
Section II. MAINTENANCE OF FUEL TANK
4-2. FUEL TANK.
a. Inspect. On ASK equipped generators, refer to
Operator and Organizational Maintenance Manual and
remove left panel and side closure assemblies. Inspect the
fuel tank per Operator and Organizational Maintenance
Manual.
b. Remove. Remove fuel tank and remove compo-
nents per Operator and Organizational Maintenance Man-
ual.
c. Test. Plug all but one opening in the fuel tank. Con-
nect a regulated low pressure air supply to tank opening.
Apply 3/4 to 1-1/4 psi to tank and submerge tank into water.
Check for leaks.
d. Repair.
WARNINGS
Observe all safety precautions when soldering
fuel tank. Avoid breathing fumes generated by
lead soldering. Eye protection is required.
Hot refueling of generators while they are oper-
ating poses a safety hazard and should not be
attempted. Hot engine surfaces and sparks pro-
duced from the engine and generator circuitry
are possible sources of ignition. Severe injury,
death and/or damage to the equipment may
result.
(1) Repair leaks in fuel tank by soldering,
(2) Clean repaired area with dry cleaning solvent
Federal Specification P-D- 680.
(3) Paint as required with MIL-T-704, type A,
semigloss, olive drab, color no. 24087.
e. Install.
(1) On ASK equipped generators, refer to Opera-
tor and Organizational Maintenance Manual and install left
panel and side closure assemblies. Install the fuel tank and
components per Operator and Organizational Maintenance
Manual.
(2) Fill tank with fuel oil.
Change 7
4-1/(4-2 blank)
