TM 5-3895-383-24
Fuel Transfer Pump
Fuel Transfer Pump
(1) Screen (if equipped). (2) Inlet check valve (3) Spring. (4)
Piston assembly. (5) Outlet check valve. (6) Piston check
valve. (7) Tappet assembly. (8) Cam. (9) Passage.
The fuel transfer pump is located in the front housing of the
governor. The pump is activated by cam (8) attached to the
shaft of the governor drive gear. Piston assembly (4) and
tappet assembly (7) are stroked up and down by cam (8) and
spring (3).
Fuel enters the transfer pump through screen (1) and inlet
check valve (2). On the upstroke of piston assembly (4), inlet
check valve (2) closes. Outlet check valve (6) closes to
prevent fuel from being puled back in the pump from the outlet.
As pressure increases above piston assembly (4), piston check
valve (6) opens to allow fuel to fill passage (9).
On the downstroke, increasing fuel pressure in passage (9)
causes piston check valve (6) to close and outlet check valve
(5) to open, pushing fuel to the main fuel filter and engine.
Inlet check valve (2) opens to allow fuel to fill the cavity above
piston assembly (4).
During engine shutdown, the check valves are held closed by
springs.
6-8
