GM Service Manual Online
For 1990-2009 cars only

Important: 

   • Before attempting the Fuel Tank Leak Check place a dry chemical (Class B) fire extinguisher near the work area.
   • Before removing the fuel tank for a suspected leak, make sure the fuel pipes are not leaking onto the fuel tank. Once removed, make sure fuel is not leaking around the fuel sender gasket.
   • This check requires a fuel sender assembly, fuel filler cap, and a fuel sender gasket to be installed in the fuel tank.

  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 31-38 kPa (4½-5½ 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 .