Warning: Refer to Battery Disconnect Warning in the Preface section.

Note: 

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief.
3. Drain the fuel tank. Refer to Fuel Tank Draining.
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. 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.
8. Locate a stand or fixture suitable to support the weight of the fuel tank and water.
9. Turn the in-frame rail fuel tank over so that the modular reservoir assembly opening is facing down.
10. Install side mounted fuel tanks upright and horizontal on stand of fixture and remove the drain plug and set aside for re-installation.
11. Turn the fuel tank over so that the modular reservoir assembly opening is facing down.

Note: 

•	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.

•	Do not drill any access or drain holes in the fuel tank.

12. Using a high pressure water spray-wand, spray all interior surfaces with clean/non-contaminated water. Be sure to spray all internal tank surfaces including fore and aft sections of tank behind baffles, while allowing water to drain out modular reservoir assembly opening or drain hole. Perform each wash cycle for a minimum of 30 seconds using a minimum of 4 liters (1 gallon) of clean/non-contaminated water.
13. Using a high pressure air wand, dry all interior tank surfaces. Tank should be tipped accordingly to facilitate removal of water. Assure pressurized air does not contain any contaminants.
14. Repeat steps 10 and 11 for a total of 3 wash/dry cycles.
15. Hand dry tank surfaces with a white towel to confirm dryness and cleanliness. Use a non-metallic extension to push the towel beyond tank baffles.
16. If equipped with a fuel drain plug:

•	Remove the old sealant from the drain plug male threads and tank drain female threads.

•	Apply new (.05 mm thick) coat of sealant (P/N 9985253) to drain plug male threads and tank drain female threads.

Caution: Refer to Fastener Caution in the Preface section.

•	Install the tank drain plug.

Tighten
Tighten the tank drain plug to 54 N·m (40 lb ft).

17. Install the fuel sender assembly. Refer to Fuel Sender Assembly Replacement.
18. Install the fuel tank. Refer to Fuel Tank Replacement.
19. Refill the fuel tank.
20. Install the fuel filler cap.
21. Connect the negative battery cable.
22. Inspect for leaks:

22.1.

Turn ON the ignition for 2 seconds.

22.2.

Turn OFF the ignition for 10 seconds.

22.3.

Turn ON the ignition.

22.4.

Inspect for fuel leaks.