GM Service Manual Online
For 1990-2009 cars only

Caution: Place a dry chemical (Class B) fire extinguisher near the area before performing a Fuel Tank Leak Check. Before removing the fuel tank for a suspected leak, make sure that the fuel pipes or the tubes are not leaking onto the tank. Once removed, make sure that the fuel is not leaking around the fuel sender O-ring. Failure to follow these precautions may result in personal injury.

    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. Relieve the fuel system pressure. Refer to the Fuel Pressure Relief .
  3. Drain the fuel tanks. Refer to Fuel Tank Draining .
  4. Remove the fuel tanks. Refer to Fuel Tank Replacement .
  5. Remove the fuel tank vapor pipe from the vehicle.
  6. Cap or plug the following on the left fuel tank:
  7. • The 3 fuel sender assembly pipes.
    • The fuel tank vent hose.
    • The fuel pressure sensor pipe.
  8. Cap or plug the 2 fuel sender assembly pipes on the right fuel tank.
  9. Install the crossover hose to both fuel tanks.
  10. Tighten
    Tighten the crossover hose clamps to 4 N·m (35 lb in).

  11. Install the fuel tank vapor pipe to both fuel tanks.
  12. Cap or plug the open ends of the fuel tank vapor pipe.
  13. Notice: Do not submerge the fuel tank assembly in water in order to check for leaks in the fuel tank. Submerging the fuel tank in water may damage the electrical components mounted on the fuel tank.

  14. Apply a soap solution to the outside of the fuel tanks and the pipe and hose connections.
  15. Apply 10 kPa (1½ psi) to the fuel fill hose on the left fuel tank. Air bubbles appearing from the fuel tank(s), pipes or connections indicate a leak.
  16. Replace the fuel tank if it is leaking. Refer to Fuel Tank Replacement .