GM Service Manual Online
For 1990-2009 cars only

Fuel Tank Leak Check EFI/MFI

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.

  1. This check requires the fuel sender and o-ring to be installed.
  2. Disconnect the battery cables.
  3. Drain the fuel tank (refer to Fuel Tank Draining ).
  4. Remove the fuel tank (refer to Fuel Tank Removal).
  5. Cap the fuel feed tube and the fuel return tube on the fuel sender.
  6. Connect a piece of hose to the filler tube nipple and plug the opposite end.
  7. Submerge the tank in water or apply a soap solution to the outside of the tank.
  8. Apply 35 kPa (5 psi) air pressure to the vent hose of the fuel tank (a leak will show up as bubbles).