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Home >> GMC >> 2002 >> C3500 HD 8.1 G, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 8.1L >> Repair Instructions >> Fuel System Cleaning >> Fuel Tank Cleaning
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Fuel Tank Cleaning

Important: 

CAUTION: Refer to BATTERY DISCONNECT CAUTION in Cautions and Notices.
  1. Disconnect the negative battery cable.
  2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure .
  3. Drain the fuel tank. Refer to Fuel Tank Draining Procedure .
  4. Remove the fuel tank. Refer to Fuel Tank Replacement (Side)  or Fuel Tank Replacement (Rear) .
  5. Remove the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .
  6. Inspect the fuel pump strainer. If the strainer is contaminated, replace the fuel pump.
  7. Inspect the fuel pump inlet for dirt and debris. Replace the fuel pump if you find dirt or debris in the fuel pump inlet.

    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.

  8. Flush the fuel tank with hot water.
  9. Pour the water out of the fuel sender assembly opening. Rock the tank to verify that removal of the water from the tank is complete.
  10. Install the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .
  11. Install the fuel tank. Refer to Fuel Tank Replacement (Side)  or Fuel Tank Replacement (Rear) .
  12. Refill the fuel tank.
  13. Install the fuel filler cap.
  14. Connect the negative battery cable.
  15. Inspect for leaks:
    1. 15.1. Turn ON the ignition for 2 seconds.
    2. 15.2. Turn OFF the ignition for 10 seconds.
    3. 15.3. Turn ON the ignition.
    4. 15.4. Inspect for fuel leaks.