Dodge RAM TRUCK 1500 1995 Service Manual page 1085

FUEL DELIVERY SYSTEM—EXCEPT DIESEL 14 - 3
must be replaced. Refer to Fuel Pump Module Removal
for procedures. Perform the Fuel System Pressure Re­
lease procedure before servicing the fuel pump.
FUEL PUMP MODULE REMOVAL
WARNING: THE F U E L S Y S T E M IS UNDER A CON­
STANT P R E S S U R E ( E V E N WITH THE ENGINE OFF).
B E F O R E SERVICING THE F U E L P U M P MODULE,
F U E L S Y S T E M P R E S S U R E MUST B E R E L E A S E D .
CAUTION: Whenever the fuel pump module is ser­
viced, the locknut and gasket must be replaced.
(1) Drain the fuel tank. Refer to Draining Fuel
Tank in the Fuel Tank section of this group.
(2) Remove fuel tank. Refer to the Fuel Tank sec­
tion of this group.
(3) Note the direction of the fuel filter/fuel pres­
sure regulator, the pressure relief/rollover valve and
the fuel pump electrical connector. These should all
be pointed to the drivers side of the vehicle.
(4) The fuel pump module locknut is threaded onto
the fuel tank. Remove the fuel pump module locknut
(Fig. 1). The fuel pump module will spring up when
the locknut is removed.
(5) Remove module from fuel tank.
DISASSEMBLY—FUEL IAUGE SENDING UNIT
(1) Remove sending unit mounting screws (Fig. 2).
(2) Mark the sending unit electrical wires before re­
moval for correct installation. Carefully disconnect elec­
trical wires from sending unit. Remove sending unit.
(3) Reverse order of removal for installation.
IN-TANK FUEL FILTER
The in-tank filter is attached to the bottom of the
fuel pump module (Fig. 2).
(1) Pry the mounting tabs back and remove the in-
tank fuel filter.''
(2) Install new fuel filter into retaining tabs.
FUEL PUMP MODULE INSTALLATION
CAUTION: Whenever the fuel pump module is ser­
viced, the locknut and gasket must be replaced.
(1) Using a new gasket, position fuel pump module
into opening in fuel tank. The fuel filter/fuel pressure
regulator, the pressure relief/rollover valve and the fuel
pump electrical connector should all be pointed to the
drivers side of the vehicle before tightening locknut.
(2) Position new locknut over top of fuel pump module.
(3) Tighten locknut.
(4) Install fuel tank. Refer to Fuel Tank Installa­
tion in this section.
AUXILIARY FUEL SUPPLY FITTING
An auxiliary (capped) fuel supply fitting is located
on the top of the fuel pump module (Fig. 1). This fit­
ting will be available only on diesel powered models,
and models with either a 5.9L V-8 heavy duty or 8.0L
V-10 engine, and all cab-chassis models. This fitting
supplies a non-pressurized auxiliary fuel source.
FUEL FILTER/FUEL PRESSURE REGULATOR
A combination fuel filter and fuel pressure regula­
tor is used on all gas powered engines. It is pressed
into a rubber grommet located on the top of the fuel
pump module (Fig. 4). A separate frame mounted fuel
filter is not used with gas powered engines.
Fuel Pressure Regulator Operation: The pres­
sure regulator is a mechanical device that is not con­
trolled by the powertrain control module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 241-310 kPa (35-45
psi) at the fuel injectors. It contains a diaphragm, cali­
brated springs and a fuel return valve. The internal fuel
filter (Fig. 3) is also part of the assembly.
Fuel is supplied to the filter/regulator by the elec­
tric fuel pump through an opening tube at the bot­
tom of filter/regulator (Fig. 3).
The fuel pump module contains a check valve to
maintain some fuel pressure when the engine is not
operating. This will help to start the engine.
If fuel pressure at the pressure regulator exceeds
approximately 45 psi, an internal diaphragm closes
and excess fuel pressure is routed back into the tank
through the pressure regulator. A separate fuel re­
turn line is not used with any gas powered engine.
INTERNAL
FUEL FILTER
FUEL INLET J9314-170
Fig. 3 Side View—Filter/Regulator