Fuel Pump: Service and Repair
Fig. 9 Fuel Pump Module:
FUEL PUMP MODULE
The fuel pump module is installed in the top of the fuel tank Fig. 9. The fuel pump module contains the following:
- Electric fuel pump.
- Fuel pump reservoir
- Inlet strainer.
- Fuel pressure regulator.
- Fuel gauge sending unit
- Fuel supply and return line connections
The inlet strainer, fuel pressure regulator and level sensor are the only serviceable items. If the fuel pump requires service, replace the fuel pump module.
ELECTRIC FUEL PUMP
The electric fuel pump is located in and is part of the fuel pump module. It is a positive displacement, gerotor, immersible pump with a permanent magnet electric motor.
The fuel pump module is suspended in fuel in the fuel tank. The pump draws fuel through a strainer and pushes it through the motor to the outlet.
The pump contains two valves.
- One valve relieves internal fuel pump pressure and regulates maximum pump output.
- The second valve, in the pump outlet, maintains pump pressure during engine off conditions.
The fuel pump relay provides voltage to the fuel pump.
The fuel pump has a maximum deadhead pressure output of approximately 900 kPa (130 psi).
The regulator adjusts fuel system pressure to approximately 338 kPa (49 psi).
Fig. 10 Fuel Pump Module Locknut:
ELECTRICAL PUMP REPLACEMENT
The electric fuel pump is not serviceable. If the fuel pump needs replacement, the complete fuel pump module must be replaced. Perform the Fuel System Pressure Release procedure before servicing the fuel pump. Fuel Pressure Release
WARNING: Release fuel system pressure before servicing fuel system components. Service vehicles in well ventilated areas and avoid ignition sources. NEVER smoke while servicing the vehicle.
FUEL PUMP MODULE REMOVAL
1. Remove fuel filler cap and perform Fuel System Pressure Release procedure. Fuel Pressure Release
2. Disconnect negative cable from auxiliary jumper terminal.
3. Remove fuel tank.
4. Disconnect fuel filter lines from fuel pump module.
5. Clean top of tank to remove loose dirt and debris.
6. Using Special Tool #6856 Fuel Pump Module Ring Spanner, remove locknut to release pump module Fig. 10.
WARNING: The fuel reservoir or the fuel pump module does not empty out when the tank is drained. The fuel in the reservoir may spill out when the module is removed.
Fig. 11 Fuel Pump Module Removal:
7. Remove fuel pump module and 0-ring from tank Fig. 11. Discard 0-ring.
FUEL PUMP MODULE INSTALLATION
1. Wipe seal area of tank clean. Place a new 0-ring on the ledge between the tank threads and the pump module opening.
2. Position fuel pump module in tank.
- Make sure the alignment tab on the underside of the pump module flange sits in the corresponding notch in the fuel tank.
CAUTION: Over tightening the pump lock ring may result in a leak.
3. While holding the pump module in position, install locknut. Tighten locknut to 40 ft lb torque using special tool #6856.
4. Install fuel tank and fuel filter.
5. Fill fuel tank with clean fuel. Check for leaks.
6. Install negative cable to auxiliary jumper terminal.
Fig. 12 Inlet Strainer Removal:
FUEL PUMP INLET STRAINER SERVICE - REMOVAL
1. Remove fuel pump module.
2. Using a thin straight blade screwdriver, carefully pry back the locking tabs on fuel pump reservoir and remove the strainer Fig. 12.
3. Remove strainer 0-ring from the fuel pump reservoir body.
4. Remove any contaminants by washing the inside of the fuel tank.
INSTALLATION
1. Lubricate the strainer 0-ring with clean motor oil.
2. Insert strainer 0-ring into outlet of strainer so that it sits evenly on the step inside the outlet.
3. Push strainer onto the inlet of the fuel pump reservoir body. Make sure the locking tabs on the reservoir body lock over the locking tangs on the strainer.
4. Install fuel pump module.