GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

Notice: Cap the fittings and plug the holes when servicing the fuel system in order to prevent dirt and other contaminants from entering the open pipes and passages.

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.

Important: When the fuel tank is cleaned, the fuel pump fuel strainer must be inspected. If the fuel pump fuel strainer is contaminated, the strainer must be replaced and the fuel pump must be inspected.

Important: Always maintain cleanliness when servicing the fuel system components.

  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. Refer to Fuel Sender Assembly Replacement .
  5. Inspect the fuel pump inlet for dirt and debris. If dirt and debris are found, the fuel pump needs to be replaced.
  6. Flush the fuel tank with hot water.
  7. Pour the water out of the fuel sender assembly opening in the fuel tank. Rock the fuel tank in order to ensure that the removal of the water from the fuel tank is complete.
  8. Allow the tank to dry completely before reassembly.
  9. Install the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .
  10. Install the fuel tank. Refer to Fuel Tank Replacement .
  11. Replace the fuel filter. Refer to In-Line Fuel Filter Replacement .
  12. Add fuel and install the fuel filler pipe cap.
  13. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  14. Inspect for leaks:
  15. 14.1. Turn the ignition ON for 2 seconds.
    14.2. Turn the ignition OFF for 10 seconds.
    14.3. Turn the ignition ON.
    14.4. Inspect for fuel leaks.