Oil & Fuel air in fuel system

[mark vetter]

Hi gang, while baling, my M8540 began starving for fuel. Tractor has 750 hrs and is like new. Drained tank,changed fuel filter, drained water separator. made sure oring intact and tight. Tractor will idle all day but not handle a load without starving for fuel. The water separator level constantly goes from full to half,in a rhythm. I have bled to the injector pump using the hand pump on filter but have made no real headway. Any ideas?

 

[Rmart30]

Have you blown back thru the fuel line into tank? Not by mouth but with compressed air.

 

[mark vetter]

that was to be my next step. I cut the old fuel filter up and inspected it. didnt seem overly plugged. My fuel supplier is now using biofuel at 10%.Not sure if that can be an issue. I have seen the screen plug before in the tank. Thanks for the reply.

 

[Dave M7040]

On the Orange forum another owner with similar issues finally got the solution.

Here is what he said:

I finally got my neighbor who is a qualified diesel tech to come help me. He pumped hand pump much longer than the other people I had helping me & engine started running so I guess it had air between hand pump & inj pump.
Thanks to all that replied,

Dave M7040

 

[Tx Jim]

Is fuel tank venting? I once owned a M4900 that acted very similar to your tractor. I found a fuel passageway clogged in water separator housing causing the fuel starvation.

 

[FatTire]

I think Tx Jim's suggestion is a good one. But also wondering if the fuel filter you put on was Kubota OEM or an aftermarket filter?

 

[mark vetter]

thanks for the tips folks. After finding out what the fuel path is from tank to inj. pump, I blew air back thru the water separator to the tank. I then bled system using the pump on fuel filter. fired it up and everything looked good,baled hay all day today without a hitch. I looked at the fuel filter guts again and a thin pasty clay feeling material seems to have coated the entire surface. From now on if i see the water separator surging like it was i will believe the lift pump is starving for suction.

 

[Tx Jim]

Mark
Thanks for update. I'm glad you got it running.
Jim

 

[Rmart30]

thanks for the tips folks. After finding out what the fuel path is from tank to inj. pump, I blew air back thru the water separator to the tank. I then bled system using the pump on fuel filter. fired it up and everything looked good,baled hay all day today without a hitch. I looked at the fuel filter guts again and a thin pasty clay feeling material seems to have coated the entire surface. From now on if i see the water separator surging like it was i will believe the lift pump is starving for suction.

Pretty common thing especially those with 90* petcocks and fittings coming out of the tank. Doesnt take much to clog that little hole up. glad ya got it going.