MT250D no 3pt lift, FEL & P/S ok

[Lunyfringe]

Anyone have any ideas on where to go from here?

the 3pt lift just QUIT.. it's done this a couple times before, but I was able to "unstick" it by cycling the steering wheel (not sure why that worked, but it did).. but now it's >zero< lift..

FEL works great, Power Steering still effective..

I pulled the hydraulic feed to to the pressure relief valve under the seat (on left side) and found I have good volume of oil there, and there appears to be good pressure and the relief valve is not dumping the pressure there... also pulled the plug on the right side under the seat and have >zero< fluid volume or pressure... /forums/images/graemlins/confused.gif

so I presume the control valve is dumping the fluid?
can these be had as an assembly, or can they be rebuilt, or do I probably just have a spring/o-ring displaced?

Thanks in advance for any assistance... I have a service manual on order... hopefully that will provide guidance as well..

Gary S.

 

[Bird]

Gary, I don't know about your tractor, but I had the same thing happen to a Kubota a couple of times (scared me the first time) and it was very simply a matter of the FEL joystick not being completely centered each time. All I had to do was wiggle the joystick a little to get it exactly centered so the valves were completely closed to let the hydraulic oil pressure continue on to the 3-point hitch.

 

[Lunyfringe]

Thanks for the quick reply, but I am getting good oil volume/pressure at the rear pressure relief valve (on the left side under the seat)... which is past the FEL & P/S units...

Correct me if I'm wrong, but figured I wouldn't get any pressure/volume there if the FEL were at fault...

 

[BillG_in_TX]

Here's a recent discussion about a similar problem and it's resolution.

 

[Bird]

I'm not sure how you'd know if you were getting any pressure to amount to anything without a pressure gauge. If you had the same problem I had, I would expect some oil flow but not enough pressure to work the 3-point. And of course, you may have an entirely different problem, but that's the only one I've encountered personally.

 

[Lunyfringe]

Fixed it this weekend, turned out to be internal relief valve on the control valve, not the FEL...

Inside the housing, under the seat, there's a control valve that has 3 plungers in it- 2 are driven by the 3-pt height control & feeback from the height of the 3-pt... the 3rd is a pressure relief valve.. it was stuck open... dead givaway was when I used a compressed air nozzle w/ a rubber tip to apply pressure where fluid is directed back there, and it was dumping all the air into the Diff. case..

Not sure why, maybe had to do with the lever being too far in the "up" position due to a bent cover for the lever.. I've adjusted the upper limit to try & prevent it from happening again...

at least it was a no-parts fix...but had to take the rear fenders, etc off to access the part.. /forums/images/graemlins/crazy.gif

Thanks for the attempts to diagnose (impossible without seeing the tractor)

 

[Bird]

Glad you got it fixed. I've never had a pressure relief valve stick open.

 

[Lunyfringe]

Thanks, I'm rather known around my friends to come up with the "doozeys" that stump the experts... /forums/images/graemlins/grin.gif /forums/images/graemlins/tongue.gif