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.

  1. Install the J 41415-40 fill tank cap adaptor.
  2. Connect the J 41413 EVAP pressure/purge diagnostic station to the fill tank cap adaptor.
  3. With a scan tool, seal the EVAP system.
  4. Raise the vehicle on a hoist. Refer to Vehicle Lifting Caution in Cautions and Notices.
  5. With the EVAP diagnostic station, maintain 15 in. Hg (3.75 kPa) within the fuel tank.
  6. Important: It may be necessary to partially lower the fuel tank to inspect the top of the fuel tank and fuel sender assembly O-ring. Refer to Fuel Tank Replacement .

  7. With the J 41416 ultrasonic leak detector, test for leaks in the fuel tank and EVAP pipes.
  8. Visually inspect for fuel leaking from the fuel tank.
  9. If a leak is detected in one of the following components, refer to the appropriate procedure:
  10. • For a fuel tank leak, refer to Fuel Tank Replacement .
    • For a fuel sender O-ring or fuel sender leak, refer to Fuel Sender Assembly Replacement .
    • For a fuel or EVAP pipe leak, refer to Fuel Hose/Pipes Replacement - Chassis .