GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • EN-48279 Main Fuel Pump Locking Ring Remover/Installer
    •  EN-48278 Sub Fuel Pump Locking Ring Remover/Installer

Removal Procedure

    Caution: Refer to Relieving Fuel Pressure Caution in the Preface section.


    Object Number: 1760006  Size: SH
  1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
  2. Caution: Refer to Battery Disconnect Caution in the Preface section.

  3. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  4. Fold the rear seat.
  5. Lift up the carpet and the insulation.
  6. Remove the main and sub fuel pump access covers.

  7. Object Number: 1760008  Size: SH
  8. Disconnect the electrical connector at the sub fuel pump assembly.

  9. Object Number: 1785018  Size: SH
  10. Install EN-48279 to the sub fuel pump and turn it counterclockwise.
  11. Remove the sub fuel pump lock ring.
  12. Important: Be careful not to damage the fuel sender for the correct fuel leveling while removing the fuel pump assembly from the fuel tank.

  13. Remove the sub fuel pump assembly and the O-ring from the fuel tank.

  14. Object Number: 1760009  Size: SH

    Important: O-ring should not be contaminated by fuel.

  15. Disconnect the main fuel pump-to-sub fuel pump connecting hose at the sub fuel pump.

  16. Object Number: 1760011  Size: SH
  17. Disconnect the electrical connector at the main fuel pump assembly.
  18. Disconnect the fuel feed line.

  19. Object Number: 1785005  Size: SH
  20. Install EN-48279 to the main fuel pump and turn it counterclockwise.
  21. Remove the main fuel pump lock ring.
  22. Remove the main fuel pump assembly and the O-ring from the fuel tank.

Installation Procedure


    Object Number: 1760013  Size: SH
  1. Clean all of the mating surface on the both fuel pump and fuel tank.
  2. Important: 

       • Do not reuse the main fuel pump O-ring.
       • Be sure that the arrow on the main fuel pump as assembly should be aligned with the arrow on the fuel tank.
       • Be careful not to damage the fuel sender for the correct fuel leveling while installing the fuel pump assembly to the fuel tank.

  3. Position the new main fuel pump O-ring and the main fuel pump first into the fuel tank in the same location as removed.

  4. Object Number: 1760009  Size: SH
  5. Pull the main fuel pump-to-sub fuel pump connecting hose towards the sub fuel pump assembly.
  6. Connect the main fuel pump-to-sub fuel pump connecting hose at the sub fuel pump.

  7. Object Number: 1760018  Size: SH
  8. Position the new sub fuel pump O-ring and the sub fuel pump into the fuel tank in the same location as removed.

  9. Object Number: 1760008  Size: SH
  10. Install the sub fuel pump lock ring by turning EN-48278 clockwise.
  11. Connect the electrical connector at the sub fuel pump.

  12. Object Number: 1760011  Size: SH
  13. Install the main fuel pump lock ring by turning the EN-48279 clockwise.
  14. Connect the electrical connector at the main fuel pump.
  15. Connect the fuel feed line.

  16. Object Number: 1760006  Size: SH
  17. Install the main and sub fuel pump access covers.
  18. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  19. Perform an operational check of the fuel pump.
  20. Fold the rear seat back to the original position.