TM-9-2350-311-10

TM 9-2350-311-10

1–14 EQUIPMENT

1–14.2 Fuel System

OPERATION AND DESCRIPTION — CONTINUED

The fuel system flow diagram shows the interaction between the electrical system and fuel system to determine the

flow of fuel.

UPPER FUEL TANK. The upper fuel tank (1) provides additional fuel to the lower fuel tank (2). Filling of both fuel

tanks takes place through the filler neck (3) of the upper fuel tank.

LOWER FUEL TANK, The lower fuel tank (2) provides for fuel storage and for the return of unused fuel from the fuel

return system (4).

ELECTRIC FUEL PUMPS. The electric fuel pumps (5) are activated by the MASTER switch on the instrument

panel (M109A2/M109A3) or by an oil pressure switch (M109A4/M109A5). These electric fuel pumps distribute fuel

from the lower fuel tank (2) to the fuel distribution center (6). When engine is not operating, the electrical fuel

pumps, activated by the fuel prime switch on the driver’s fixed instrument panel, pumps fuel from the primary fuel

filter (7) to the secondary fuel filter (8).

FUEL DISTRIBUTION CENTER, The fuel distribution center (6) distributes fuel to the primary fuel filter (7).

PRIMARY FUEL FILTER. The primary fuel filter (7) is the first filter from the upper fuel tank,

ENGINE-DRIVEN FUEL PUMP. The engine-driven fuel pump (9) boosts fuel pressure and delivers fuel to the

engine.

SECONDARY FUEL FILTER. The secondary fuel filter (8) filters fuel a second time for additional impurities.

ENGINE. The engine (Model 7083-7396) (10) or LHR engine (Model 7083-7391) (11) burns fuel,

FUEL RETURN SYSTEM. The fuel return system (4) distributes excess fuel back to the lower fuel tank (2).

1-24

TM-9-2350-311-10 - Page 62 of 775