GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

Important: Important when flushing the fuel tank, the fuel and water mixture needs to be treated as a hazardous material. The material needs to be handled in accordance with all local, state and federal laws and regulations.

Fuel Tank Cleaning

  1. Relieve the fuel system fuel pressure. Refer to Fuel Pressure Relief .
  2. Drain the fuel tank. Refer to Fuel Tank Draining .
  3. Remove the fuel tank. Refer to Fuel Tank Replacement .
  4. Remove the fuel sender assembly.
  5. Important: When ever the fuel tank is cleaned, the fuel pump fuel strainer must be inspected. If the fuel pump fuel strainer is contaminated, the fuel pump fuel strainer must be replaced and the fuel pump must be inspected.

  6. Inspect the fuel pump inlet for dirt and debris. If dirt and debris are found, the fuel pump needs to be replaced.
  7. Pour the water out of the fuel sender assembly opening in the fuel tank. Rock the fuel tank in order to be sure that the removal of the water from the fuel tank is complete.
  8. Install the fuel sender assembly.
  9. Install the fuel tank. Refer to Fuel Tank Replacement .
  10. Add fuel and install the fuel tank filler pipe cap.
  11. Install the negative battery cable.
  12. Inspect for leaks.
  13. 11.1. Turn the ignition switch ON for 2 seconds.
    11.2. Turn the ignition switch OFF for 10 seconds.
    11.3. Turn the ignition switch ON.
    11.4. Check for fuel leaks.