Dodge dakota 2002 Service Manual page 1773

14 - 76 FUEL DELIVERY - DIESEL
FUEL TRANSFER PUMP (Continued)
OPERATION
The purpose of the fuel transfer pump is to supply
(transfer) a low-pressure fuel source: from the fuel
tank, through the fuel filter/water separator and to
the fuel injection pump. Here, the low-pressure is
raised to a high-pressure by the fuel injection pump
for operation of the high-pressure fuel injectors.
Check valves within the pump, control direction of
fuel flow and prevent fuel bleed-back during engine
shut down.
Maximum current flow to the pump is 5 amperes.
With the engine running, the pump has a 100 per-
cent duty-cycle with a minimum pressure of 11.5 psi.
The transfer pump is self-priming: When the key is
first turned on (without cranking engine), the pump
will operate for approximately 1/2 second and then
shut off. The pump will also operate for up to 25 sec-
onds after the starter is engaged, and then disen-
gaged and the engine is not running. The pump
shuts off immediately if the key is on and the engine
stops running.
The fuel volume of the transfer pump will always
provide more fuel than the fuel injection pump
requires. Excess fuel is returned from the injection
pump through an overflow valve, and then back to
the fuel tank.
REMOVAL
The fuel transfer pump (fuel lift pump) is attached
to the rear of the fuel filter/water separator housing
(Fig. 25).
(1) Drain fuel from fuel filter housing. Refer to
Fuel Filter/Water Separator - Removal. See Draining.
(2) Disconnect electrical connector (Fig. 25) from
fuel transfer pump.
(3) Disconnect fuel tank supply line from fuel
transfer pump extension line. Do this at disconnec-
tion point at inside of left inner frame rail (Fig. 26).
Refer to quick-connect fittings for procedures. The
fuel line extension is permanently attached to
the transfer pump. Do not attempt to discon-
nect fuel line at transfer pump.
(4) Remove 4 pump mounting bolts (hex-allen),
and remove pump from fuel filter housing.
(5) Confirm that transfer pump o-ring is also
removed from fuel filter housing.
INSTALLATION
(1) Install a new o-ring to fuel transfer pump.
(2) Lubricate o-ring and OD of transfer pump inlet
connector.
(3) Position fuel transfer pump onto fuel filter
housing. Do not use mounting bolts to draw
transfer pump to filter housing.
Fig. 25 FUEL TRANSFER (LIFT) PUMP
1 - FILTER HOUSING
2 - ELEC. CONNECTOR
3 - FUEL TRANSFER (LIFT) PUMP
4 - FUEL LINE EXTENTION
5 - MOUNTING BOLTS (4)
Fig. 26 TRANSFER PUMP FUEL LINE CONNECT
1 - LEFT INNER FRAME RAIL
2 - FUEL RETURN LINE
3 - FUEL SUPPLY LINE
4 - QUICK-CONNECT FITTING
DR