Fuel System Cleaning

WARNING: THIS PROCEDURE WILL NOT REMOVE ALL FUEL VAPORS. DO NOT ATTEMPT ANY REPAIR ON THE TANK OR FILLER NECK WHERE HEAT OR FLAME IS REQUIRED, AS AN EXPLOSION RESULTING IN PERSONAL INJURY COULD OCCUR.

NOTE: If trouble is due to contaminated fuel or foreign material that has been put into the fuel tank, it can usually be cleaned. If the tank is rusted internally, it should be replaced.

PROCEDURE:

1. Relieve the fuel system pressure, refer to FUEL SYSTEM PRESSURE RELIEF.
2. Disconnect the negative battery cable.
3. Drain the fuel tank, refer to FUEL TANK DRAINING.
4. Remove the fuel tank, refer to FUEL TANK REMOVAL AND FUEL LEVEL SENDING UNIT.
5. Remove the fuel inlet filter and inspect for contamination. If the filter is plugged, replace. (Leave the fuel line disconnected)
6. Move the tank away from heat, flame, or other source of ignition. Remove the fuel tank gauge sending unit assembly and inspect the filter. If the filter is contaminated, a new filter should be installed when reassembled.
7. Complete draining the tank by rocking and allowing the fuel to run out access hole.
8. Purge the fuel tank, refer to FUEL TANK PURGING.
9. Disconnect the fuel feed pipe and use air pressure to clean the fuel line and the fuel return line. Apply air pressure in the direction fuel normally flows through the line.
10. Use low air pressure to clean the pipes on the tank unit.
11. Install the fuel tank level sending unit assembly, with a new seal, into the tank and install the tank. Connect the tank unit wires and all fuel pipes except the fuel line at the engine.
12. Disconnect the fuel feed hose from the chassis pipe at the engine.
13. Connect a hose onto the fuel pipe and insert the other end into an empty 1 gallon can.
14. Connect the battery cable.
15. Put 23 liters (six gallons) of clean fuel in the tank and apply 12 volts to the fuel pump test connector to pump two liters (two quarts) of fuel into the can. This will purge the fuel pump.
16. Remove the hose and connect the fuel line. Use new "O" rings as needed.
17. Start the engine and check for leaks.