M7040 fuel system bleeding

[Tx Jim]

As I previously suggested loosen then tighten each inj line while engine is running to determine if air in inj line is a problem

 

[TruckinFool]

As I previously suggested loosen then tighten each inj line while engine is running to determine if air in inj line is a problem

Sorry, I didn't see it. Are you sure this is safe? What are the rail pressures? I've been told you can kill yourself doing this on trucks?

 

[Tx Jim]

M7040 isn't an ultra high pressure common rail system. As I previously stated CAUTION: keep your FINGERS from coming in contact with spraying diesel fuel but I've survived bleeding air out of inj lines many times. Final line is BE CAREFUL!!!!!!!!!!

 

[TruckinFool]

10-4 Thank you

 

[whis]

its a bleed screw, loosen and pump primer till fuel comes out

 

[Tx Jim]

its a bleed screw, loosen and pump primer till fuel comes out

whis
I agree with screw OP inquired about being a bleed screw BUT if his engine is truly running bad loosening that bleed screw won't correct the problem.

 

[TruckinFool]

So if you remove that screw you loose suction from the tank. Not sure what its purpose is but its not to bleed the system. I think you can use it to drain the bowl back to the tank before removal? Anyway, after messing with it and priming, I no longer have air bubbles in the top of the bowl while running. Noise never changed but I think all is good.

 

[whis]

its to bleed water filter

 

[TruckinFool]

But its the suction side?

 

[Tx Jim]

But its the suction side?

Are you concerned that water filter is between fuel tank & lift pump? My M7040 is one of the easiest diesel engines I've ever owned/worked on to bleed the air out of the fuel system and get it to run.