Fuel Pressure: Testing and Inspection

Fuel System Pressure Test - 6.0L Diesel





WARNING: Do not smoke, carry lighted tobacco or have an open flame of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

WARNING: When handling fuel, always observe fuel handling precautions and be prepared in the event of fuel spillage. Spilled fuel may be ignited by hot vehicle components or other ignition sources. Failure to follow these instructions may result in serious personal injury.

1. Release the fuel system pressure. For additional information, refer to Fuel System Pressure Release - 6.0L Diesel Service and Repair.

2. Disconnect the battery ground cable. For additional information, refer to Battery.

3. Detach the coolant hoses from the Air Cleaner (ACL) outlet pipe.





4. NOTE: ACL side shown, engine side similar.

Loosen the clamps and remove the ACL outlet pipe.





5. Loosen the clamps on the Charge Air Cooler (CAC) duct at the intake manifold adapter.





6. Loosen the clamp on the CAC duct at the CAC.





7. Remove and position the CAC duct aside.





8. NOTE: The diagnostic pressure test port plug is located on the side of the secondary fuel filter housing.

Remove the diagnostic pressure test port plug.





9. Install the High Pressure Pump Test Adapter.





10. Install a commercially available fuel pressure gauge.





11. Position the CAC duct and the air cleaner outlet pipe into place.

12. Connect the battery ground cable. For additional information, refer to Battery.

13. NOTE: It may take more than one key cycle to pressurize the fuel system.

Cycle the ignition key and wait 3 seconds to pressurize the fuel system. Check for leaks before starting the engine.

14. NOTE: Allow the vehicle to run before taking any fuel pressure readings to make sure that all air is out of the fuel system to prevent inaccurate readings.

Test the fuel system pressure to make sure it is within the specified range. For additional information, refer to Specifications.





15. NOTE: Open the drain valve slowly to relieve the fuel system pressure. This may drain fuel from the system. Place the fuel in a suitable container.

If the commercially available fuel pressure gauge has a drain valve, open the drain valve and release the fuel system pressure.





16. When the fuel system pressure test is complete, install the diagnostic pressure test port plug.
- Tighten to 7 Nm (62 lb-in).





17. Position the CAC duct into place.





18. Tighten the clamp on the CAC duct at the CAC.
- Tighten to 12 Nm (106 lb-in).





19. Tighten the clamps on the CAC duct at the intake manifold adapter.
- Tighten to 12 Nm (106 lb-in).





20. NOTE: ACL side shown, engine side similar.

Install the ACL outlet pipe and tighten the clamps.





21. Attach the coolant hoses to the ACL outlet pipe.