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.

Important: This check requires a fuel sender assembly, fuel filler cap, and a fuel sender gasket to be installed in the fuel tank.

    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 Procedure .
  3. Drain the fuel tank. Refer to Fuel Tank Draining .
  4. Remove the fuel tank. Refer to Fuel Tank Replacement .
  5. Cap the fuel feed pipe, the fuel return pipe, and the EVAP pipe on the fuel sender assembly.
  6. Connect a piece of hose to the vent pipe.
  7. Submerge the fuel tank in water or apply a soap solution to the outside of the fuel tank.
  8. Apply 7-10 kPa (1-1½ psi) air pressure to the piece of hose on the fuel tank vent pipe. Air bubbles appearing from the fuel tank indicate a leak.
  9. Replace the fuel tank if it is leaking. Refer to Fuel Tank Replacement .