MF 6290 fuel problems

[Antonis Theod]

Hello!
I am new farmer and i am trying to find a solution about my tractor problem(s).We are struggling for like 5-6 years now some problems and i think its time to fix them.I drive a MF (Massey Fergusson) 6290 and i am facing problems with the back fuel tank.The tractor has arround 5000hrs.It is losing fuel from the fuel cap and i cant find a solution.Last year it is started to lose fuel from the tank airway up on the tractor.The two problems appear when the tractor works on hard jobs (plowing) for 10 minutes.I will post a photo.

I tried to unblock the airway from possible block with compressed air and i bought a new fuel tank cap without any difference.Have you got any ideas? Thanks for your time and sorry for my bad english.

 

[Speedstar]

It is the boost pressure seal on the fuel pump that is the problem putting pressure back in to the fuel tank it will be under powered as well

 

[Mur Huwcun]

Is it pressurising the tank? If so, does it have a boost aneroid on the injector pump? Is it underpowered? If so the seal/diaphragm will be gone in that.

Edit: was few seconds too late to the party!!

 

[Antonis Theod]

It is the boost pressure seal on the fuel pump that is the problem putting pressure back in to the fuel tank it will be under powered as well

Thanks for the fast response! Since i dont know how was the tractor before i dont know if its underpowered or not. Will fuel pump need change or?

 

[Antonis Theod]

Is it pressurising the tank? If so, does it have a boost aneroid on the injector pump? Is it underpowered? If so the seal/diaphragm will be gone in that.

Edit: was few seconds too late to the party!!

Thanks for the fast response! I cant actually respose to your questions so i dont know. Some times the tank has air in it and after i take off the cap i can hear the air going off.

 

[Farmer_Joe]

I believe you can just replace the seal in the pump but I’ve not looked at one on a mf before was in another application

 

[Antonis Theod]

I have another question about the pressure in the tank.After a reasearch i did i read that the fuel tank cap has a pressure relief valve.Why does it keep having so much pressure?

 

[davidroberts30]

I have another question about the pressure in the tank.After a reasearch i did i read that the fuel tank cap has a pressure relief valve.Why does it keep having so much pressure?

your turbo is blowing into a fuel line and down the return pipe into tank with that rubber seal gone
last i looked the seal was about £10

 

[Farmer_Joe]

As above,

the pressure will be very high and is likely to overload the relief valve on the cap.

 

[e3120]

This issue, though common, is one of those rare quick and cheap repairs with the added bonus of releasing trapped power.