Dodge Ram Truck 1500-2500-3500. Manual — part 1483

TANK - FUEL

DESCRIPTION - DIESEL

The fuel tank is similar to the tank used with gasoline powered models. The tank is equipped with a separate fuel
return line and a different fuel tank module for diesel powered models. The electric fuel transfer pump (lift pump) is
attached to the fuel pump module. Refer to Fuel Tank Module for additional information.

REMOVAL - DIESEL

Fuel Tank Draining

Due to a one-way check valve installed into the fuel fill opening fitting at the tank, the tank cannot be drained con-
ventionally at the fill cap.

1. Raise vehicle.

2. If vehicle is equipped with 4 doors and a 6 foot (short) box, remove left-rear tire/wheel.

3. Thoroughly clean area at top of fuel tank around fuel tank module.

4. Loosen clamp and disconnect rubber fuel fill hose at tank.

5. Drain fuel tank by attaching drain hose from an approved draining station to fuel fill fitting of tank.

Tank Removal

1. Support tank with a hydraulic jack.

2. Remove 2 fuel tank strap nuts (5) and remove both tank support straps.

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3. Carefully lower tank a few inches and disconnect fuel pump module electrical connector at top of tank. To dis-

connect electrical connector: Push upward on red colored tab to unlock. Push on black colored tab while remov-
ing connector.

4. Disconnect fuel supply and return lines at fuel tank module. Refer to Quick-Connect Fittings for procedures.

5. Continue to lower tank for removal.

6. If fuel tank is to be replaced, remove fuel tank module from tank. Refer to Fuel Tank Module Removal/Installation

procedures.

INSTALLATION - DIESEL

1. If fuel tank is to be replaced, install fuel tank module into tank. Refer to Fuel Tank Module Removal/Installation

procedures.

2. Position fuel tank to hydraulic jack.

3. Raise tank until positioned near body.

4. Connect fuel tank module electrical connector at top of tank.

5. Connect fuel supply and return lines to tank module.

6. Continue raising tank until positioned snug to body.

7. Install and position both tank support straps. Install 2 fuel tank strap nuts and tighten. Tighten rear strap nut

first. Refer to Torque Specifications.

8. Remove hydraulic jack.

9. Connect rubber fill hose to fuel fill tube and tighten clamp.

10. Install tire / wheel (if necessary).

11. Lower vehicle.

12. Fill fuel tank with fuel.

13. Start engine and check for fuel leaks near top of module.

MODULE - FUEL TANK

DESCRIPTION

.

The fuel tank module is installed in the top of the fuel tank. The fuel tank module contains the following compo-
nents:

•

An electric fuel transfer (lift) pump

•

Fuel reservoir

•

A separate in-tank fuel filter

•

Fuel gauge sending unit (fuel level sensor)

•

Fuel supply line connection

•

A special lockring to retain module to fuel tank

•

Fuel return line connection

OPERATION

Refer to Fuel Gauge Sending Unit.

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REMOVAL

1. Drain and remove fuel tank. Refer to Fuel Tank

Removal/Installation.

2. Note rotational position of module before attempt-

ing removal. An indexing arrow is located on top of
module for this purpose.

3. Position Special Tool 9340 (3) into notches on out-

side edge of lockring (5).

4. Install 1/2 inch drive breaker bar (1) to tool 9340

(3).

5. Rotate breaker bar counter-clockwise to remove

lockring.

6. Remove lockring. The module will spring up slightly

when lockring is removed.

7. Remove module from fuel tank. Be careful not to

bend float arm while removing.

INSTALLATION

CAUTION: Whenever the fuel pump module is serviced, the rubber seal (gasket) must be replaced.

1. Using a new seal (gasket), position fuel pump mod-

ule into opening in fuel tank.

2. Position lockring (5) over top of fuel pump module.

3. Rotate module until embossed alignment arrow

points to center alignment mark. This step must be
performed to prevent float from contacting side of
fuel tank. Also be sure fuel fitting on top of pump
module is pointed to drivers side of vehicle.

4. Install Special Tool 9340 (3) to lockring.

5. Install 1/2 inch drive breaker (1) into Special Tool

9340 (3).

6. Tighten lockring (clockwise) until all seven notches

have engaged.

7. Install

fuel

tank.

Refer

to

Fuel

Tank

Removal/Installation.

PUMP - FUEL TRANSFER

DESCRIPTION

The fuel transfer pump (fuel lift pump) is part of the fuel pump module. The fuel pump module is located in the fuel
tank. The 12–volt electric pump is operated and controlled by the Engine Control Module (ECM). The ECM controls
a relay in the Power Distribution Center (PDC) for transfer pump operation.

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

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the fuel injection pump for operation of the high-pressure fuel injectors. Check valves within the pump, control direc-
tion 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 percent duty-cycle.

The transfer pump is self-priming: When the key is first turned on (without cranking engine), the pump will operate
for approximately 2 seconds and then shut off (Note: When ambient temperatures are cold enough to cause the
intake air heaters to operate, the fuel lift pump will operate during the entire intake air pre-heat cycle). The pump will
also operate for up to 25 seconds after the starter is engaged, and then disengaged 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 a part of the fuel tank module. It is not serviced separately. Refer to Fuel
Tank Module Removal or Installation for procedures.

INSTALLATION

The fuel transfer pump (fuel lift pump) is a part of the fuel tank module. It is not serviced separately. Refer to Fuel
Tank Module Removal or Installation for procedures.

VALVE - CASCADE OVERFLOW

DESCRIPTION

The cascade overflow valve (4) is located on the top/
rear side of the fuel injection pump.

OPERATION

When the fuel control actuator (FCA) is opened, the maximum amount of fuel is being delivered to the fuel injection
pump. The cascade valve regulates how much excess fuel is used for lubrication of the injection pump, and is also
used to route excess fuel through the drain circuit and back into the fuel tank.

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