GM Service Manual Online
For 1990-2009 cars only

Fuel Sender Assembly Replacement RPO NU6

Special Tools

J 45722 Fuel Sender Lock Ring Wrench

Removal Procedure

  1. Remove the fuel tank. Refer to Fuel Tank Replacement .
  2. Disconnect the evaporative emission (EVAP) lines and the fuel line from the sender. Refer to Plastic Collar Quick Connect Fitting Service .
  3. Reposition the fuel feed and EVAP lines in order to access the lock ring.

  4. 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: 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.

  5. 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.

  6. Object Number: 1575962  Size: SH
  7. Remove the fuel sender (2) from the fuel tank.
  8. Remove and discard the fuel sender O-ring seal.
  9. Clean and inspect the fuel sender assembly O-ring seal sealing surfaces.

  10. 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.

  11. 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.
  12. If the warpage is less than 0.41 mm (0.016 in), the lock ring does not require replacement.
  13. If the warpage is greater than 0.41 mm (0.016 in), the lock ring must be replaced.

Installation Procedure


    Object Number: 1575962  Size: SH
  1. Position the NEW fuel sender O-ring seal onto the fuel tank.
  2. Install the fuel sender (2) into the fuel tank. Ensure that the align tab is in the proper location.
  3. Push down the fuel sender and position the lock ring (1) onto the fuel tank.

  4. 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.

  5. Use the J 45722 in order to install the fuel sender lock ring. Turn the fuel sender lock ring in a clockwise direction.
  6. Connect the fuel line and the EVAP lines to the sender. Refer to Plastic Collar Quick Connect Fitting Service .
  7. Install the fuel tank. Refer to Fuel Tank Replacement .