Diesel Fuel System Contamination Repair/Flushing - Key Turned to Run or Engine Started

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

For information on Ford Color Coded Illustrations refer to OEM Color Coding .

Flushing

NOTE: This procedure is to be used when metal debris and/or fuel system contamination is present.

NOTE: This procedure is for flushing the low pressure fuel system lines from the fuel tank, through both fuel filters and the HP (high pressure) fuel injection pump to remove all contaminates before installing new fuel system components.

NOTE: Leave the original fuel filters, HP fuel injection pump, fuel lines, fuel rail and injectors in place until the flushing procedure is completed to prevent contamination of replacement components.

NOTE: The Fuel Filter/Water Separator must be inspected during filter replacement to verify no low pressure fuel system damage. If metal debris or DEF contamination is present, the Fuel Filter/Water Separator must be replaced.

NOTE: All remaining low pressure fuel lines can be reused if no physical damage is present.

Remove and flush the fuel pump and sender unit. Refer to: Fuel Pump and Sender Unit .
NOTE: Dispose of contaminated fuel in accordance with local laws and regulations.

Flush the fuel tank out.
Install the fuel pump and sender unit. Refer to: Fuel Pump and Sender Unit .
Fill the fuel tank with fresh, clean, good quality diesel fuel.
NOTE: Dispose of contaminated fuel in accordance with local laws and regulations.

Using an suitable container, drain the Fuel Filter/Water Separator of any residual liquids.
NOTE: Dispose of contaminated fuel in accordance with local laws and regulations.

Disconnect the fuel return line by the fuel tank.
Use Scan Tool Active Commands or cycle the ignition to "RUN" to activate the low pressure fuel pump to flush the lines.
NOTE: Dispose of contaminated fuel in accordance with local laws and regulations.

Allow the fuel pump to run for 3 minutes or until approximately 3 gallons of fuel has been flushed through the system.
Connect the fuel return line.
Replace both primary and secondary fuel filters. Refer to: Fuel Filter . Refer to: Fuel Filter Element .
After the flush is completed, replace the following HP fuel system components:
- Fuel injection pump
- Fuel rail supply tube
- Fuel injector supply tubes
- Fuel injector fuel return line
- Fuel rails
- Fuel injectors
- Fuel pressure and temperature sensor (located on the engine low pressure line near the secondary fuel filter)