Very weak bucket curl

[ssrider]

I have a 1964 MF 150 with aftermarket Allied loader. Loader is run off the tractors internal hydraulic pump. I bought the tractor last year and it's always had a very weak bucket curl. The loader arms have plenty of lifting power and will lift the tractor no problem. The odd thing is the bucket will support any weight I put in it no problem if lifted with loader arms only. If I try to curl even a half bucket of dirt it won't, the bucket will just remain in the same position. I changed the control valve to a joystick style a few months after I bought it, so the valve cant be the problem. Any ideas on what the problem could be?

 

[JoelD]

How many and how large are bucket rams?

What is the geometry like? Although unlikely the problem

Did you test pressure to rams?

Joel

 

[LD1]

Sounds like bucket seals are in need of replacing. If bucket seals are worn, fluid can bypass the piston seals and return to tank. More noticeable on lower flow (GPM) hydraulics. Do you notice a difference in "power" from idle vs WOT?

 

[J_J]

Extend the bucket fully, and then remove the rod end hose and then extend the cyl more and see if fluid is pushing past the piston seals.


Do the same with retract and remove the base end hose and see if the seals are leaking both ways.

You can also tee a hyd gauge in the work port and see if the cyl can build up relief pressure.

 

[ssrider]

There's 2 bucket rams, I believe 2" diameter. I haven't checked pressure how would I do that?

If the cylinder seals are warn and leaking would the bucket still support weight without slowly dropping? I don't really notice a difference in curling power at wot, Just quicker cycle.

J.J. That's not a bad idea. I will probably try that.

One thing I forgot to mention is the bucket cylinders also feel "spongy". If I jump on the bucket it bounces slightly.

 

[Soundguy]

You were just told how to check pressure.

does your joystick control have a separate relief? do you know what it is set at?

 

[ssrider]

Yes I know I was told how to check pressure. I replied to comments in the order I read them. Should have deleted that question after reading the answer in JJ post.

Yes the joystick has its own relief. I believe it came set at 2000 psi. I'm also pretty sure the relief valve on tractor trips and the joystick doesn't. Maybe the relief valve on tractor is the problem? I suppose the pressure test would answer this question

 

[LD1]

If the cylinder seals are warn and leaking would the bucket still support weight without slowly dropping? I don't really notice a difference in curling power at wot, Just quicker cycle.

100% possible.

When trying to curl, the valve is pumpong fluid in the rod side port and opening the based end port to tank to allow fluid to return. If the seals are shot, some of the fluid you are pumping in the front can return to tank after leaking past the seals. Thats why I said it would be worse at a lower flow rate (slower RPM) vs a high RPM.

When just holding a load, there is no way for the fluid to return to tank. Even if the seals are shot. And for fluid to leak past the piston means drawing a vacuum and sucking in into the cylinder or out of the fluid for the bucket to drift.

 

[Soundguy]

Yes I know I was told how to check pressure. I replied to comments in the order I read them. Should have deleted that question after reading the answer in JJ post.

Yes the joystick has its own relief. I believe it came set at 2000 psi. I'm also pretty sure the relief valve on tractor trips and the joystick doesn't. Maybe the relief valve on tractor is the problem? I suppose the pressure test would answer this question

you need to see what pressure the system is tripping at, then go from there. As LD1 mentioned, you could be bypassing on the curl cyld's. if they are parallel, only takes one to leak..

 

[ssrider]

Thanks for the replies. I will check the trip pressure as mentioned. I could see it being a bad cylinder seal. They are cheap cylinders and look like they've had some abuse.