GM Service Manual Online
For 1990-2009 cars only

Fuel Tank Replacement Passenger/Cargo Van

Removal Procedure

Tools Required

J 39765 Fuel Sender Locknut Wrench

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Drain the fuel from the tank. Refer to Fuel Tank Draining Procedure .
  3. Raise the vehicle.

  4. Object Number: 34270  Size: SH
  5. Remove the fuel tank off-road shield, if equipped.

  6. Object Number: 34269  Size: SH
  7. Loosen the filler neck hose clamp (2) at the fuel tank (1) and disconnect the fuel tank filler neck from the fuel tank.

  8. Object Number: 34270  Size: SH
  9. Support the fuel tank and remove the tank straps and insulator strips (3) and (4), if equipped.
  10. Lower fuel tank shield.

  11. Object Number: 34270  Size: SH
  12. Lower the fuel tank (2). Disconnect the fuel feed and vapor hoses. Refer to Quick Connect Fitting(s) Service (Metal Collar) or Quick Connect Fitting(s) Service (Plastic Collar) .
  13. Disconnect the electrical connector at the sender.

  14. Object Number: 65287  Size: SH
  15. Remove the fuel sender assembly and seal ring, using tool J 39765 . Discard the old seal ring.

Installation Procedure


    Object Number: 65287  Size: SH
  1. Install the new seal ring and reinstall the sender using tool J 39765 .
  2. Raise the tank slightly and reconnect the fuel feed and vapor hoses and the electrical connections at the sender.

  3. Object Number: 34270  Size: SH
  4. Raise the tank fully.

  5. Object Number: 34269  Size: SH

    Important: The fuel tank filler neck clamps must be properly positioned and aligned. Otherwise, the filler neck may become disconnected from the fuel tank.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  6. Reinstall the fuel tank filler neck (3) to the tank (1).
  7. Tighten
    Tighten the clamp (2) to 2.75 N·m (24.3 lb in).


    Object Number: 34270  Size: SH

    Notice: Tighten the strap fasteners by steps, alternating between the fasteners, until the specified torque is reached. A failure to tighten the strap fasteners as specified will cause the bottom of the tank to flex upward. This will result in the fuel gauge indicating that there is fuel remaining in the tank when the tank is empty.

    Important: When removing or replacing the fuel tank, the fuel tank support fasteners should never be reused. Always use new fasteners when installing the fuel tank.

  8. Install the fuel tank brackets ( 3) with insulator strips in place. Tighten the strap nuts to 20 N·m (15 lb ft).
  9. Install the fuel tank off-road shield, if equipped.
  10. Replenish the fuel in the tank. Reinstall the fuel tank filler cap.
  11. Notice: Do not use fuels containing methanol in order to prevent damage and corrosion to the fuel system.

  12. Reconnect the negative battery cable. If a memory retention device was not used, please reset (to the extent possible) all devices that lost their memory after the battery was disconnected.
  13. Check for leaks.

Fuel Tank Replacement Commercial/RV Cutaway Van

Removal Procedure

Tools Required

J 39765 Fuel Sender Locknut Wrench

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Drain the fuel from the fuel tank. Refer to Fuel Tank Draining Procedure .
  3. Raise the vehicle. (This must be done with a frame hoist to allow the rear suspension to hang.)

  4. Object Number: 34268  Size: SH
  5. Remove the filler hose (3) and vent hose from the fuel tank (1).

  6. Object Number: 34272  Size: SH
  7. Support the fuel tank and remove the fuel tank straps (3).

  8. Object Number: 34272  Size: SH
  9. Lower the fuel tank shield and the fuel tank (2).

  10. Object Number: 18448  Size: SH
  11. Disconnect the fuel feed and vapor hoses. Refer to Quick Connect Fitting(s) Service (Metal Collar) or Quick Connect Fitting(s) Service (Plastic Collar) .
  12. Disconnect the electrical connector at the sender.

  13. Object Number: 34272  Size: SH
  14. Remove the fuel tank (2).

  15. Object Number: 65287  Size: SH
  16. Remove the fuel sender and the seal ring, using tool J 39765 . Discard the old seal ring.

Installation Procedure


    Object Number: 65287  Size: SH
  1. Install the new seal ring and reinstall the sender using tool J 39765 .
  2. Raise the tank and reconnect the electrical connector at the sender.

  3. Object Number: 18447  Size: SH
  4. Reconnect the fuel feed and vapor hoses. Refer to Quick Connect Fitting(s) Service (Metal Collar) or Quick Connect Fitting(s) Service (Plastic Collar) .

  5. Object Number: 34272  Size: SH
  6. Raise the tank (2) fully and reinstall the tank shield.

  7. Object Number: 34272  Size: SH

    Important: When removing or replacing the fuel tank, the fuel tank support fasteners should never be reused. Always use new fasteners when installing the fuel tank.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  8. Reinstall the tank straps (3).
  9. Tighten
    Tighten the bolts (4) to 20 N·m (15 lb ft).


    Object Number: 34268  Size: SH
  10. Reinstall the filler hose (3) and the vent hose to the tank.
  11. Replenish the fuel. Reinstall the fuel tank filler cap.
  12. Notice: Do not use fuels containing methanol in order to prevent damage and corrosion to the fuel system.

  13. Reconnect the negative battery cable.

Inspection Procedure

Important: The fuel tank filler neck clamps must be properly positioned and aligned. Otherwise, the filler neck may become disconnected from the fuel tank.

Turn the ignition switch ON for two seconds then turn the switch OFF for ten seconds. Again turn the ignition switch ON and check for fuel leaks.