JD 650 Compact 3 pt hydraulics not lifting weight

[Edensgardenertx]

We need more information. The FEL and 3pt only share hydraulic fluid & pressure. All the components that use that pressure are discrete. Including cylinders and controls.
What position did it stop i?. Will it move without any weight? How much? Does the relief valve make noise when you try to lift it with weight?
I suppose you checked the normal thing like the trans/hydraulic fluid and it is full and not milky.
BTW, power steering was rare on the 650. JD offered an aftermarket kit. Does yours have PS?

control on side of seat for 3pt, will raise w/o weight, fluid is full and clear. No ps. relief valve? do you mean the lever that raises? it will lift when I take off the mower/disk - it's slow though. Thanks!

 

[rScotty]

control on side of seat for 3pt, will raise w/o weight, fluid is full and clear. No ps. relief valve? do you mean the lever that raises? it will lift when I take off the mower/disk - it's slow though. Thanks!

There is a drop speed regulator under the front of the seat. It is a needle valve that will control drop speed of an implement ...but not raising speed. Have you worked with that? If you raise up the 3pt arms and put weight on the arms, turning in that valve clockwise should slow and then completely prevent the arms from dropping . Does it?

So far I believe what you have is simply fixed. Sounds like the O ring seal on the 3pt lift piston is shot. WHere a piston in a motor would have a ring set, the 3pt piston has a rubber O ring. But check the valve above first.

 

[Edensgardenertx]

There is a drop speed regulator under the front of the seat. It is a needle valve that will control drop speed of an implement ...but not raising speed. Have you worked with that? If you raise up the 3pt arms and put weight on the arms, turning in that valve clockwise should slow and then completely prevent the arms from dropping . Does it?

So far I believe what you have is simply fixed. Sounds like the O ring seal on the 3pt lift piston is shot. WHere a piston in a motor would have a ring set, the 3pt piston has a rubber O ring. But check the valve above first.

are you referring to the round dial under the seat that says open/close? If so, it's pretty much frozen. I've been able to move it to the opener stage once, but it's STIFF. I've never closed it though.

o ring seal on lift piston.... where is that? I have a pdf manual, but didn't see it.

 

[WinterDeere]

are you referring to the round dial under the seat that says open/close? If so, it's pretty much frozen. I've been able to move it to the opener stage once, but it's STIFF. I've never closed it though.

o ring seal on lift piston.... where is that? I have a pdf manual, but didn't see it.

Lower the quadrant (3-pt control lever), and then see if the knob turns more easily. Or do it with the 3-point lowered and tractor off. They can be real tough to turn when there's a load on the 3-point.

 

[rScotty]

Lower the quadrant (3-pt control lever), and then see if the knob turns more easily. Or do it with the 3-point lowered and tractor off. They can be real tough to turn when there's a load on the 3-point.

Do what he says and also look again in the manual. Do you have parts or workshop manual?

That 3pt lowering speed valve can be removed entire and it has O rings too. They get old and need replacemet. Easy job, but look at the exploded diagram first.
The O ring on the lift cylinder piston requires taking the top off of the 3 pt. on most tractors. I'd have to check about the JD650. It sounds terrible but is actually an easy job.

If you want, I have some Yanmar parts and workshop manuals that are close enough & can post some images if you want. As you probably know, the JD650 is a re-badged Yanmar, and so the old Yanmar group - which has an active vintage site - is a better source for technical and mechanical info.
However, even though Yanmar made the JDx50 series - not many parts cross over.

 

[2manyrocks]

When I had similar trouble with my yanmar ym226d 3 pt, it was the o rings which were actually easy to replace like rscotty said.

 

[Edensgardenertx]

Do what he says and also look again in the manual. Do you have parts or workshop manual?

That 3pt lowering speed valve can be removed entire and it has O rings too. They get old and need replacemet. Easy job, but look at the exploded diagram first.
The O ring on the lift cylinder piston requires taking the top off of the 3 pt. on most tractors. I'd have to check about the JD650. It sounds terrible but is actually an easy job.

If you want, I have some Yanmar parts and workshop manuals that are close enough & can post some images if you want. As you probably know, the JD650 is a re-badged Yanmar, and so the old Yanmar group - which has an active vintage site - is a better source for technical and mechanical info.
However, even though Yanmar made the JDx50 series - not many parts cross over.

I have a pdf file from the net - I'm sure it's just a parts manual.

I have someone coming by tomorrow - I'm going to show all of this to him and see if he can help - I can not turn that thing, no matter what. I'll spray some wd40 on it today and see if that helps loosen it.

He's got a walk behind he's having to tear down himself, but this doesn't sound quite as complicated so maybe he'll welcome the challenge.

Thank you!

 

[Edensgardenertx]

Do what he says and also look again in the manual. Do you have parts or workshop manual?

That 3pt lowering speed valve can be removed entire and it has O rings too. They get old and need replacemet. Easy job, but look at the exploded diagram first.
The O ring on the lift cylinder piston requires taking the top off of the 3 pt. on most tractors. I'd have to check about the JD650. It sounds terrible but is actually an easy job.

If you want, I have some Yanmar parts and workshop manuals that are close enough & can post some images if you want. As you probably know, the JD650 is a re-badged Yanmar, and so the old Yanmar group - which has an active vintage site - is a better source for technical and mechanical info.
However, even though Yanmar made the JDx50 series - not many parts cross over.

post away. Please. I have a farmer coming out tomorrow and he's probably more capable than me on something like this - so I'll share it all with him and see if we can figure it all out. Thank you!

 

[beenthere]

Schematic from JD parts of 650 lowering valve.

https://partscatalog.deere.com/jdrc/sidebyside/equipment/21841/referrer/navigation/pgId/1293348

Page back a couple for the lift cylinder schematics.

 

[rScotty]

post away. Please. I have a farmer coming out tomorrow and he's probably more capable than me on something like this - so I'll share it all with him and see if we can figure it all out. Thank you!

I don't have a JD650 book, but here are some from a possibly similar Yanmar model.
They are what I would be looking for if I was doing this job.

The parts #23 to 29 in the dotted inset 11 show the lowering valve. That could be your problem if yours is stuck. It's a valve very much like any needle valve.
Parts 17 thru 22 are the relief (safety) valve. Clean it up too. sometimes the valve parts are so stuck you have to take off the head #12 and push the parts out from inside.

But the needle valve only controls speed DOWN. If yours is slow going up or has no power then my guess is that you need to take off the 3pt head part #12, and replace the O ring #38 on the piston #37. . Hone the cylinder.

All the O rings are standard if JD doesn't have them an o ring shop will. Be sure to get an O ring #14 too.
luck,
rScotty