JD 650 Compact 3 pt hydraulics not lifting weight

[Edensgardenertx]

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

View attachment 2907552View attachment 2907553

awesome, thanks!

 

[rScotty]

awesome, thanks!

I think the best link for yours was in post #19 by "beenthere". Real nice diagrams for the JD650. BTW, that link wouldn't work on Safari, but linked up fine on Google.

Interesting to compare the same mechanism from Yanmar and JD. The similarities are a lesson all in themselves.
rScotty