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 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 Draining Fuel Tank.
  4. Remove the fuel tank. Refer to Fuel Tank and Fuel Filler Pipe 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 filler pipe nipple and plug the opposite end.
  7. Submerge the fuel tank in water or apply a soap solution to the outside of the fuel tank.
  8. Apply 35 kPa (5 psi) air pressure to the vent hose on the fuel tank. Air bubbles appearing from the fuel tank indicate a leak.
  9. Replace the fuel tank if it is leaking. Refer to Fuel Tank and Fuel Filler Pipe Replacement.