MF 550 Airlocking overnight

laurence997

Hi lads,

I have a problem with a MF 550 that maybe someone could shed some light on.
When started from cold in the morning it airlocks, but, when bled, keeps working for the whole day. As the fuel tank is above the engine it's unlikely that its a leak, and its not the fault of any of the usual suspects (filters have been changed, fuel tank cleaned, strainer on tank outlet cleaned, clear flow of diesel to the fuel primer pump, injector pump overhauled etc. all to no avail)
I've come across many different airlocking problems, but nothing like this before, it really has me stumped
If anybody has come across a similar problem maybe they could point me in the right direction.

Thanks in advance

Solnskaya

Have you checked the lift pump? Is there dirt in the tank blocking the outlet? Are any of the connections in the supply lines poor -ie missing a washer, loose pipe on metal fitting, hairline crack in filter housing, twisted o-ring between fuel filter and housing?? If it was mine, I would replace the fuel filter housing, lift pump, fuel filter and ALL the hose from the tank to the injector pump. Easy to do, cheap, and less aggravating in the long term. Best of luck with it.

Suckler

Is The fuel tank not under the cab on the 550?

pajero12

Check the bleed screw on the Diesel filter, there might be air getting in there. Take out the screw, wrap it in plumbing tape and see if that solves the problem.