GM Service Manual Online
For 1990-2009 cars only

Special Tools

J 45722 Fuel Sender Lock Nut Wrench

Removal Procedure

    Warning: Refer to Battery Disconnect Warning in the Preface section.


    Object Number: 331709  Size: SH
  1. Disconnect the negative battery cable.
  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief.
  3. Drain the fuel tank. Refer to Fuel Tank Draining.
  4. Remove the fuel tank.

  5. Object Number: 1642096  Size: SH

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

    Caution: 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.

    Note: 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.

  6. Use the J 45722 and a long breaker-bar in order to unlock the fuel sender lock ring.
  7. Remove the fuel sender assembly and the seal. Discard the seal.
  8. Caution: Drain the fuel from the fuel sender assembly into an approved container in order to reduce the risk of fire and personal injury. Never store the fuel in an open container.

  9. Clean the fuel sender sealing surfaces.

  10. Object Number: 1617750  Size: SH

    Note: 

       • Some lock rings were manufactured with "DO NOT REUSE" stamped into them. These lock rings may be reused if they are not damaged or warped.
       • Inspect the lock ring for damage due to improper removal or installation procedures. If damage is found, install a NEW lock ring.
       • Check the lock ring for flatness.

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

Installation Procedure


    Object Number: 331709  Size: SH

    Warning: 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.

  1. Install the new seal on the fuel tank.
  2. Note: The fuel strainer must be in a horizontal position when the fuel sender is installed in the tank. When installing the fuel sender assembly, assure that the fuel strainer does not block full travel of the float arm.

  3. Install the fuel sender assembly into the fuel tank.

  4. Object Number: 1642096  Size: SH

    Note: 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. Install the fuel tank.
  7. Refill the fuel tank.
  8. Tighten the fuel filler cap.
  9. Connect the negative battery cable.
  10. Inspect for leaks:
  11. 8.1. Turn ON the ignition for 2 seconds.
    8.2. Turn OFF the ignition for 10 seconds.
    8.3. Turn ON the ignition.
    8.4. Inspect for fuel leaks.