GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 45722 Fuel Sender Lock Ring Wrench

Removal Procedure

Caution: In order to reduce the risk of fire and personal injury that may result from a fuel leak, always replace the fuel sender gasket when reinstalling the fuel sender assembly.

Notice: Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering the open pipes and passages.


    Object Number: 1594369  Size: SH
  1. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .
  2. Remove the rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement .
  3. Remove the fuel sending unit access cover bolts.
  4. Remove the access cover.

  5. Object Number: 1594359  Size: SH
  6. Disconnect the fuel sender electrical connector (3).
  7. Disconnect the fuel pressure sensor electrical connector (5).

  8. Object Number: 1594372  Size: SH
  9. Disconnect the fuel fill pipe evaporative emission (EVAP) pipe quick connect fitting (1). Refer to Plastic Collar Quick Connect Fitting Service .
  10. Disconnect the fuel feed pipe quick connect fitting (1). Refer to Plastic Collar Quick Connect Fitting Service .

  11. Object Number: 1642096  Size: SH

    Notice: Avoid damaging the lock ring. Use only J-45722 to prevent damage to the lock ring.

    Notice: Do Not handle the fuel sender assembly by the fuel pipes. The amount of leverage generated by handling the fuel pipes could damage the joints.

    Important: 

       • The fuel sender assembly may spring up from its position.
       • When removing the fuel sender assembly from the fuel tank, be aware that the reservoir bucket is full of fuel. It must be tipped slightly during removal to avoid damage to the float. Discard the fuel sender assembly O-ring and replace it with a new one.
       • Carefully discard the fuel in the reservoir bucket into an approved container.

    Important: Do NOT use impact tools. Significant force will be required to release the lock ring. The use of a hammer and screwdriver is not recommended. Secure the fuel tank in order to prevent fuel tank rotation.

  12. Use the J 45722 and a long breaker-bar in order to unlock the fuel sender lock ring. Turn the fuel sender lock ring in a counterclockwise direction.

  13. Object Number: 1594373  Size: SH
  14. Raise the fuel sender up slightly.
  15. Connect the large EVAP canister quick connect fitting. Refer to Plastic Collar Quick Connect Fitting Service .
  16. Remove the fuel sender assembly.
  17. Remove and discard the fuel sender O-ring.

  18. Object Number: 1617750  Size: SH

    Important: Some lock ring were manufactured with DO NOT REUSE stamped into them. These lock rings may be reused if they are not damaged or warped.

    Important: Inspect the lock ring for damage due to improper removal or installation procedures. If damage is found, install a NEW lock ring.

    Important: Check the lock ring for flatness.

  19. Place the lock ring on a flat surface. Measure the clearance between to lock ring and the flat surface using a feeler gage at 7 points.
  20. If the warpage is less than 0.41 mm (0.016 in), the lock ring does not require replacement.
  21. If the warpage is greater than 0.41 mm (0.016 in), the lock ring must be replaced.

Installation Procedure


    Object Number: 1594373  Size: SH
  1. Install a NEW fuel sender O-ring.
  2. Install the fuel sender assembly.

  3. Object Number: 1642096  Size: SH

    Important: Always replace the fuel sender seal when installing the fuel sender assembly. Replace the lock ring if necessary. Do not apply any type of lubrication in the seal groove.

    Ensure the lock ring is installed with the correct side facing upward. A correctly installed lock ring will only turn in a clockwise direction.

  4. Using the J 45722 , rotate the fuel sender assembly lock ring clockwise until the ring is locked into place on the fuel tank.
  5. Connect the large EVAP canister quick connect fitting. Refer to Plastic Collar Quick Connect Fitting Service .

  6. Object Number: 1594372  Size: SH
  7. Connect the fuel feed pipe quick connect fitting (1). Refer to Plastic Collar Quick Connect Fitting Service .
  8. Connect the fuel fill pipe EVAP pipe quick connect fitting (1). Refer to Plastic Collar Quick Connect Fitting Service .

  9. Object Number: 1594359  Size: SH
  10. Connect the fuel pressure sensor electrical connector (5).
  11. Connect the fuel sender electrical connector (3).

  12. Object Number: 1594369  Size: SH
  13. Install the access cover.
  14. Install the fuel sending unit access cover bolts.
  15. Install the rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement .
  16. Refill the tank.
  17. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  18. Inspect for fuel leaks through the following steps:
  19. 14.1. Turn the ignition to the ON position for 2 seconds.
    14.2. Turn the ignition to the OFF position for 10 seconds.
    14.3. Turn the ignition to the ON position
    14.4. Check for fuel leaks.