How do you get air out of your fuel lines?
To purge air from the low-pressure side of the fuel system, open fuel-line unions and bleed ports downstream of the pump, one at a time, beginning with those closest to the pump, and continue pumping until fuel, and not air, runs out.
Can you change the fuel filter without priming?
Plus, once you start the vehicle, the lift pump is already sending fuel from the tank into the filter housing. For whatever it’s worth, I checked with Mike Hevster (TDI mechanic in NJ) who also said that its fine to change filters without priming under most circumstances.
Is the HPFP still running after a fuel filter change?
I don’t believe the HPFP would have run dry as there’s still fuel in the lines leading into the HPFP. There’s also fuel in the line running from the main fuel tank into the filter housing. Plus, once you start the vehicle, the lift pump is already sending fuel from the tank into the filter housing.
What should I do after a fuel filter change?
When you go to start after a FF change, crank for about 10 seconds at a time and let the starter cool down for 1/2 hour after 2 or 3 attempts. Of course the best way to purge out the air is with the maintenance manual procedure.
What causes air to be trapped in a diesel filter?
When you change a diesel fuel filter, run out of fuel or disturb the fuel system, air is trapped. When you try to start the engine this air acts as a lock, preventing the normal supply of fuel.
Why is my fuel pump not priming after a fuel filter change?
At the minimum, fill the fuel filter housing. The big concern is that the fuel pump is lubricated by diesel. I haven’t experienced any problems not priming the fuel system after a FF change.
Do you have to Prime the fuel filter?
I didn’t bother to refill the fuel filter tank either. It wouldn’t hurt to prime the system, but I don’t think it’s detrimental to not do it either. The only time I think it would be necessary to prime the system is if the entire fuel system was drained – that includes the line from the tank to the common rail.
When you go to start after a FF change, crank for about 10 seconds at a time and let the starter cool down for 1/2 hour after 2 or 3 attempts. Of course the best way to purge out the air is with the maintenance manual procedure.
When you change a diesel fuel filter, run out of fuel or disturb the fuel system, air is trapped. When you try to start the engine this air acts as a lock, preventing the normal supply of fuel.