Fuel Contamination Inspection and Cleaning
Note: This procedure checks for the presence of water and gasoline in diesel fuel that may cause injection pump and nozzle damage.
1. Remove the fuel filter element and inspect it:
• If water, gasoline or fungi/bacteria are not present, end the inspection.
• If water or fungi/bacteria are present, go to step 2.
• If gasoline is present, go to step 3.
2. Clean water from the fuel system in these steps:
A. Disconnect the batteries.
B. Drain the fuel tank.
C. Remove the fuel tank.
D. Remove the fuel pick-up/sending unit.
E. Inspect the fuel tank and fuel pick-up/sending unit for rust, fungi or bacteria:
• If no rust is present, clean the inside of the fuel tank and fuel pick-up/sending unit with hot water, then dry them with compressed air.
• If rust is present, replace the parts.
F. Disconnect the ends of the following lines:
• Lift pump suction
• Lift pump pressure
• Fuel filter outlet
• Fuel filter drain
• Fuel return
G. Inspect each of the lines and replace any rusted pipes.
H. Dry the inside of each line with low-pressure air.
I. Clean the inside of the fuel filter housing and dry it with compressed air.
J. Disconnect the electrical connector for the fuel shut-off solenoid in the injection pump.
K. Install a new fuel filter element.
L. Install the fuel pick-up/sending unit and fuel tank (add clean diesel fuel to 1/4 full).
M. Connect the following lines:
• Lift pump suction (both ends)
• Lift pump pressure (both ends)
• Fuel filter drain
• Fuel return (at injection pump)
N. Connect the fuel filter outlet and the fuel return line at the pick-up/sending unit to hoses that flow to metal containers.
O. Connect the batteries and crank the engine until clean fuel flows from the fuel filter outlet into a metal container (see Figure 7-59):
• Allow a maximum of 15 seconds cranking time, followed by 1 minute of cranking motor cooling time.
P. Connect the hose from the fuel filter outlet to the injection pump inlet.
Q. Open each injection line at its nozzle end and crank the engine until clean fuel flows from it:
• Use two wrenches when loosening the injection line fittings.
• Allow a maximum of 15 seconds cranking time, followed by 1 minute of cranking motor cooling time.
R. Tighten each injection line fitting at its nozzle:
• Use two wrenches when tightening the injection line fittings.
S. Remove the electrical connector for the fast idle/cold advance temperature switch and jumper its wiring harness terminals with an insulated wire.
T. Connect the electrical connector for the fuel shut-off solenoid in the injection pump.
U. Start and run the engine for 15 minutes while fuel flows from the fuel return line into a metal container (see Figure 7-60).
V. Stop the engine.
W. Connect the fuel return hose to the fuel pick-up/sending unit.
X. Remove the jumper wire and install the electrical connector for the fast idle/cold advance temperature switch.
Y. Clean the engine of fuel spillage.
Z. Fill the fuel tank and add a biocide, if needed.
3. Clean gasoline from the fuel system in these steps:
A. Determine a procedure:
• If the engine runs, follow steps B, C, J and K.
• If the engine does not run, begin at step C.
B. Drain the fuel tank.
C. Fill the fuel tank.
D. Disconnect the electrical connector for the fuel shut-off solenoid in the injection pump.
E. Remove the fuel filter outlet and connect it to a hose that flows to a metal container.
F. Crank the engine until clean fuel flows from the fuel filter outlet into a metal container:
• Allow a maximum of 15 seconds cranking time, followed by 1 minute of cranking motor cooling time
G. Connect the hose from the fuel filter outlet to the injection pump inlet.
H. Remove the electrical connector for the fast idle/cold advance temperature switch and jumper its terminals with an insulated wire.
I. Connect the electrical connector for the fuel shut-off solenoid in the injection pump.
J. Start and run the engine for 15 minutes.
K. Stop the engine.
L. Remove the jumper wire and install the electrical connector for the fast idle/cold advance temperature switch.
M. Clean the engine of fuel spillage.
