GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Controls - 4.8L, 5.3L, and 6.0L 🢒 Fuel Injection Fuel Rail Assembly Replacement

Removal Procedure

    Important:  An eight-digit identification number (1) is located on the fuel rail assembly. Refer to this model identification number if servicing or part replacement is required.


    Object Number: 380659 Size: SH
  1. Remove the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement in Engine Mechanical.
  2. Before removal, clean the fuel rail assembly with a spray type engine cleaner, GM X-30A or equivalent, if necessary. Follow the package instructions. Do not soak fuel rails in liquid cleaning solvent.

    3. Object Number: 389853 Size: SH
  3. Disconnect the accelerator control cable and the cruise control cable from the cable bracket.

    4. Object Number: 389031 Size: SH
  4. Disconnect the accelerator control cable and the cruise control cable from the throttle body.

    5. Object Number: 310125 Size: SH
  5. Remove the upper engine wire harness retainer nut.
  6. Disconnect the evaporative emission (EVAP) purge valve harness connector.
  7. Reposition the upper engine wire harness aside.
  8. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .

    9. Object Number: 372749 Size: SH
  9. Identify the connectors to their corresponding injectors to ensure correct sequential injector firing order after reassembly.
  10. Pull the top portion (2) of the injector connector up. Do not pull the top portion of the connector past the top of the white portion (1).

    11. Object Number: 372753 Size: SH
  11. Push the tab (1) on the lower side of the injector connector in order to release the connector from the injector.
  12. Repeat Step 12 and Step 13 for each injector connector.

    13. Object Number: 300360 Size: SH

    Notice: 

       • Remove the fuel rail assembly carefully in order to prevent damage to the injector electrical connector terminals and the injector spray tips. Support the fuel rail after the fuel rail is removed in order to avoid damaging the fuel rail components.
       • Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering open pipes and passages.

  13. Disconnect the fuel feed and return pipes (1, 2) from the fuel rail.
  14. Disconnect the fuel pressure regulator vacuum line.

    15. Object Number: 350543 Size: SH
  15. Loosen the crossover tube to right fuel rail retainer screw (22).

    16. Object Number: 376389 Size: MH
  16. Remove the fuel rail attaching bolts.
  17. Remove the fuel rail assembly.

    18. Object Number: 351185 Size: SH
  18. Remove the injector lower O-ring seal (4) from the spray tip end of each injector (3).
  19. Discard the O-ring seals.

Installation Procedure

    Object Number: 351185 Size: SH
  1. Lubricate the new lower injector O-ring seals (4) with clean engine oil.
  2. Install the new O-ring seals (4) on the spray tip end of each injector (3).

    3. Object Number: 350543 Size: SH
  3. Remove the crossover tube to the right fuel rail retainer (21).
  4. Remove the crossover tube (25) from the right fuel rail (15).
  5. Remove the O-ring (20) from the crossover tube (25).
  6. Install a new O-ring on the crossover tube.
  7. Lubricate the new O-ring with clean engine oil.
  8. Install the crossover tube (25) into the right fuel rail (15).
  9. Loosely install the crossover tube to the right fuel rail retainer (21).

    10. Object Number: 376389 Size: MH
  10. Install the fuel rail assembly to the intake manifold.
  11. Apply a 5 mm (0.020 in) band of GM P/N 12345382 threadlock, or equivalent, to the threads of the fuel rail bolts.

    12. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  12. Install the fuel rail attaching bolts.

    13. Tighten

    1. Tighten the bolts to 10 N·m (89 lb in).
    2. Tighten the right crossover pipe retainer screw to 3.8 N·m (34 lb in).

    Object Number: 300360 Size: SH
  13. Connect the fuel pressure regulator vacuum line.
  14. Connect the fuel feed and return pipes (1, 2) to the fuel rail.
  15. Connect the injector electrical connectors.
    16. • Install each connector on the proper injector in order to ensure correct sequential injector firing order.
    • Rotate the injectors as required in order to avoid stretching the wire harness.

    Object Number: 310125 Size: SH
  16. Position the upper engine wire harness in place.
  17. Connect the EVAP purge solenoid connector.
  18. Install the retainer nut to the upper engine wire harness.

    19. Tighten
    Tighten the nut to 5.5 N·m (49 lb in).


    Object Number: 389853 Size: SH
  19. Connect the accelerator control cable and the cruise control cable to the cable bracket.

    20. Object Number: 389031 Size: SH
  20. Connect the accelerator control cable and the cruise control cable to the throttle body.
  21. Install the engine sight shield mounting bracket and the bolts. Refer to Upper Intake Manifold Sight Shield Replacement in Engine Mechanical.
  22. Tighten the fuel filler cap.
  23. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  24. Use the following procedure in order to inspect for leaks:
    25. 24.1. Turn ON the ignition, with the engine OFF,for 2 seconds.
    24.2. Turn OFF the ignition for 10 seconds.
    24.3. Turn ON the ignition, with the engine OFF.
    24.4. Inspect for fuel leaks.
  25. Install the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement in Engine Mechanical.