Fuel System Cleaning Procedure

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. Have a Class B fire extinguisher near the work area.

NOTE: If the 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, the tank should be replaced.

PREPARATION:
1. Fuel system pressure must be released prior to service, refer to Fuel System Pressure Release.
2. Disconnect the negative battery cable.
3. Drain the fuel tank. Fuel Tank Draining Procedure
4. Remove the fuel tank. SEE Fuel Tank / Service and Repair.

CHECK FILTERS:
1. Remove the Inline fuel filter, and inspect for contamination. If the filter is plugged, replace it. (Leave the fuel line disconnected.)
2. Move the tank away from heat, flame, or other source of ignition. Remove the fuel pump assembly from tank, and inspect the in tank filter (screen). If the in tank filter is contaminated, clean or replace as needed.

PURGE TANK:
1. Purge the fuel tank, refer to FUEL TANK PURGE.

BLOW OUT LINES AND PUMP:
1. 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.
2. Use low air pressure to clean the pipes on the fuel pump.

FLUSH PUMP AND LINES WITH CLEAN FUEL:
1. Install the fuel pump assembly in tank, with a new seal, and install the tank.
2. Connect the fuel pump wires and all fuel pipes except the fuel line at the engine.
3. Disconnect the fuel feed hose from the chassis pipe at the engine.
4. Connect a hose onto the fuel pipe and insert the other end into an empty 1 gallon can.
5. Connect the battery cable.
6. Put 23 liters (six gallons) of clean fuel in the tank and actuate the fuel pump to pump two liters (two quarts) of fuel into the can, refer to Fuel and Air Induction / System Diagnosis. This will purge any contaminated fuel from the fuel pump.
7. Remove the hose and connect the fuel line. Use new clamps on all fuel line connections.
8. Start the engine and check for leaks.