Fuel Pump: Service and Repair

Fuel Pump Replacement (LLT)

Tools Required

EN-48896 HP Fuel Pump Installation Alignment Gage


Removal Procedure

1. Relieve the low and high side fuel system pressure. Refer to Fuel Pressure Relief (With CH 48027 - LP1, LY7) (Fuel Pressure Relief (With CH 48027) (LY7) VIN 7 W/O Direct Fuel Injection)Fuel Pressure Relief (Without CH 48027 - LP1, LY7) (Fuel Pressure Relief (Without CH 48027) VIN 7 W/O Direct Fuel Injection)Fuel Pressure Relief (With High Pressure Pump - LLT) (Fuel Pressure Relief (With High Pressure Pump (LLT) VIN V W/ Direct Fuel Injection) .
2. Remove the cross vehicle brace. Refer to Cross Vehicle Brace Replacement (Cross Vehicle Brace Replacement) .
3. Remove the high pressure fuel pump shield. Refer to Fuel Pipe Shield Replacement (LLT) (Service and Repair) .
4. Remove the intake manifold. Refer to Intake Manifold Replacement (Service and Repair) .
5. Remove the wiper module. Refer to Windshield Wiper Motor Replacement (Service and Repair)




6. Disconnect the engine wiring harness electrical connector from the high pressure fuel pump.
7. Remove the radiator surge tank outlet pipe. Refer to Radiator Surge Tank Outlet Hose/Pipe Replacement (LLT) (Service and Repair)Radiator Surge Tank Outlet Hose/Pipe Replacement (LY7/LLT) (Service and Repair)
8. Remove the low pressure feed pipe. Refer to Fuel Feed Pipe Replacement (LLT) (Service and Repair) .
9. Remove the high pressure pipe. Refer to Fuel Feed Intermediate Pipe Replacement (LLT) (Service and Repair) . Discard this pipe.
10. Remove and discard the high pressure fuel pump bolts (4).
11. Remove the high pressure fuel pump (3).
12. Remove and discard the high pressure fuel pump gasket (2).
13. Remove and discard the high pressure fuel pump O-ring.
14. Remove the high pressure fuel pump roller lifter.



Installation Procedure


Important: The camshaft must be in the base circle position before the high pressure fuel pump is installed.


1. Use the EN-48896 to ensure that the camshaft lobe is in the base circle position. At base circle the tool will be flush with the head.
2. Lubricate the high pressure fuel pump cylinder head bore and roller lifter with camshaft prelube GM P/N 12345501 (Canadian P/N 992704) or equivalent.
3. Install high pressure fuel pump roller lifter.
4. Install a NEW high pressure fuel pump O-ring.





Important: The high pressure fuel pump gasket has a retaining feature to hold the pump retaining bolts in place.


5. Position the NEW high pressure fuel pump gasket and bolts to the fuel pump.
6. Install the high pressure fuel pump to the cylinder head. Force will be required while hand tightening the bolts.

Notice: Refer to Fastener Notice (Fastener Notice) .

7. Tighten the high pressure fuel pump retaining bolts.

Tighten the fuel pump bolts to 15 N.m (11 lb ft).

8. Ensure the high pressure fuel pump and fuel rail fittings are clean prior to assembly.
9. Install a NEW high pressure fuel pipe. Refer to Fuel Feed Intermediate Pipe Replacement (LLT) (Service and Repair)
10. Install the fuel feed pipe to the high pressure fuel pump. Refer to Fuel Feed Pipe Replacement (LLT) (Service and Repair) .
11. Connect the high pressure fuel pump wiring harness.
12. Install the radiator surge tank outlet pipe. Refer to Radiator Surge Tank Outlet Hose/Pipe Replacement (LLT) (Service and Repair)Radiator Surge Tank Outlet Hose/Pipe Replacement (LY7/LLT) (Service and Repair)
13. Install the fuel tank cap.

Important: If a fuel leak accrues at the fuel rail, the fuel rail will need to be replaced.


14. Inspect for leaks using the following procedure:

1. Turn ON the ignition, with the engine OFF for 2 seconds.
2. Turn OFF the ignition, for 10 seconds.
3. Turn ON the ignition, with the engine OFF.
4. Inspect for fuel leaks.

15. Install the pressure relief cap to the fuel feed pipe.
16. Install the wiper module. Refer to Windshield Wiper Motor Replacement (Service and Repair)
17. Install the intake manifold. Refer to Intake Manifold Replacement (Service and Repair) .
18. Install the high pressure fuel pump shield. Refer to Fuel Pipe Shield Replacement (LLT) (Service and Repair) .
19. Install the cross vehicle brace. Refer to Cross Vehicle Brace Replacement (Cross Vehicle Brace Replacement) .