GM Service Manual Online
For 1990-2009 cars only

Fuel Tank Cleaning

Important: 

   • Only use oil free compressed air to blow out the fuel pipes.
   • Inspect the fuel tank internally and clean the fuel tank if you find a plugged fuel filter.

  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 Replacement.
  5. Remove the fuel sender assembly. Refer to Fuel Sender Assembly Replacement.
  6. Inspect the fuel pump strainer. Replace a contaminated strainer and inspect the fuel pump.
  7. Inspect the fuel pump inlet for dirt and debris. Replace the fuel pump and reservoir if you find dirt or debris in the fuel pump inlet.
  8. Important: When flushing the fuel tank, handle the fuel and water mixture as a hazardous material. Handle the fuel and water mixture in accordance with all applicable local, state, and federal laws and regulations.

  9. Flush the fuel tank with hot water.
  10. Pour the water out of the fuel sender assembly opening. Rock the tank to be sure that removal of the water from the tank is complete.
  11. Install the fuel sender assembly. Refer to Fuel Sender Assembly Replacement.
  12. Install the fuel tank. Refer to Fuel Tank Replacement.
  13. Refill the fuel tank.
  14. Install the fuel filler cap.
  15. Connect the negative battery cable.
  16. Inspect for leaks.
  17. 15.1. Turn the ignition switch ON for 2 seconds.
    15.2. Turn the ignition switch OFF for 10 seconds.
    15.3. Turn the ignition switch ON.
    15.4. Check for fuel leaks.