Fuel System Priming

Note

In order for the DURAMAX diesel fuel system to work properly, the fuel lines must be full of fuel and contain no air. If air gets into the fuel lines, it will be necessary to prime the fuel system to eliminate the air before operating the vehicle. Air could have entered the system in one of the following ways: The vehicle ran out of fuel. The filter was removed for service or replacement. The fuel lines were removed or disconnected for servicing. The fuel filter water drain cock was opened while the engine was running. If one or more of the above occurred, air has entered the fuel system and you will need to prime the system prior to operating the vehicle.

1. Prior to priming the engine, ensure that the following has been completed: There is fuel in the fuel tank. The fuel filter has been installed and properly tightened. The fuel lines are properly connected. The fuel filter is cool to the touch. Any dirt or debris has been removed from the fuel filter head and vent valve.
2. Turn the ignition key on for two minutes. The fuel pump will be operating and starting the priming process. Do not start the engine during the first two minutes.
3. After completing the initial prime in step 2, turn the ignition off, then back to start and crank the engine for 15 seconds.
4. If the engine does not start, repeat steps 2 and  3 until the engine starts.
5. If the engine does not run after repeating steps 2 and 3 three times, turn the ignition key OFF for 60 seconds, allowing the electronic control module (ECM) to reset.
6. Repeat the above steps until the engine starts.
7. If the engine runs, but does not run smoothly, increase the engine speed slightly by pressing the accelerator pedal. This will help to force out air through the system.
8. If the engine starts and runs but stalls again, turn the ignition key OFF for 60 seconds to reset the ECM and repeat the steps above.
9. Start the engine and allow it to idle for a few minutes.
10. Check for leaks.