GM Service Manual Online
For 1990-2009 cars only

Special Tools

J 45722 Fuel Sender Lock Ring Wrench

Removal Procedure

Important: NEW fuel tank module seals are necessary each time the fuel tank module is serviced. Obtain NEW seals for both the primary and secondary modules prior to beginning this service procedure.

    Caution: Whenever fuel line fittings are loosened or removed, wrap a shop cloth around the fitting and have an approved container available to collect any fuel.

    Notice: Clean all fuel pipe and hose connections and surrounding areas before disassembling to avoid possible contamination of the fuel system. Spray the fuel pump module cam-lock ring tang with penetrating oil prior to attempting removal.

  1. Remove the secondary fuel pump module. Refer to Secondary Fuel Tank Module Replacement .

  2. Object Number: 1857638  Size: SH
  3. Disconnect the electrical connectors from the primary fuel pump module (1) and fuel tank pressure sensor.

  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. Disconnect the fuel feed and vent lines from the fuel tank.
  7. Notice: To prevent bending of the sending unit float arm during removal, lift the pump module up slightly to disengage the orientation tabs in the tank and rotate the module 45 degrees.

  8. Remove the primary fuel pump module assembly.
  9. Important: Always replace the fuel pump module-to-tank seal, O-ring, when the fuel pump module is removed.

  10. Discard the fuel pump module-to-tank seal.
  11. If the fuel level sending unit is being replaced, remove the fuel level sender. Refer to Primary Fuel Level Sensor Replacement .

  12. 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.
       • 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.

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

Installation Procedure


    Object Number: 1857638  Size: SH
  1. If the fuel level sending unit is being replaced, install the fuel level sending unit onto the new fuel pump. Refer to Primary Fuel Level Sensor Replacement .
  2. Insert the new primary fuel pump module assembly (1) with the level sender and the new fuel pump-to-tank seal. Ensure the orientation tabs are aligned.

  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. Use the J 45722 in order to install the fuel sender lock ring. Turn the fuel sender lock ring in a clockwise direction.
  5. Connect the wiring harness to the primary fuel pump module and fuel tank pressure sensor.
  6. Install the secondary fuel pump module. Refer to Secondary Fuel Tank Module Replacement .