Hi guys, have an issue with my JD 510b, the loader bucket will not rotate up. When I fired the machine up (on a cold day), the lever to curl the bucket wouldn't work either way - curl up or down. It's a single cylinder. After a bit, probably after warming up, the bucket would curl down (to dump) but would not curl up. Ran it for while and still nothing. When I move the lever to curl the bucket up, I can see the hose to the cylinder moving, pumping fluid I guess but the bucket won't curl up. Now I have it curled all the way down (from playing with it so much). I looked today and there's now fluid leaking from the cylinder. Any thoughts on what my issue would be?
So if I'm understanding you, the cylinder is now sucked in all the way? And the rod won't extend at all? That's damn near impossible really. Only thing I can think of is a blocked line from the rod end. Any chance there's water in the system and it's got chunk of ice somewhere? With it shut off and wobble the sticks to relieve as much pressure as possible, you might try reversing the two bucket cylinder hoses where they connect just behind the cylinder, see if the problem reverses itself? If so the cylinder is probably okay, it's a blocked line or a valve issue.
Just a guess but has your piston come loose or off on the cylinder shaft inside the bore sure sounds like it to me............
If that were true the rod should extend but not retract? Except for gravity of course.....
How about the valve? does the tilt spool move as much as the loader boom spool? If there's no return to dig solenoid, then the cap over the bottom of the spool can fill with fluid and keep the spool from moving far enough. Maybe when you move the lever it releases the pressure and that's what you see as the hose moving, but it doesn't move enough to supply pressure to the other side? The downside of closed center hydraulics... with open center you'd be able to tell what the valve was doing in this case.
I misread that as the backhoe bucket cylinder, but after looking at a couple pictures of the loader setup what I said still applies I think.
I wish I could figure out how to post a pic... I haven't had a chance to get back to the machine to investigate anymore. The bucket was able to curl to the position of the piston being fully retracted (bucket is curled to full dump position). Not sure what/where the spool is. Hopefully something just froze up with the weather. I'll have to wait till it warms up to test that theory. I can also try swapping the lines, looks like that would be an easy enough test. Thanks for the replies, wish I was smarter with this stuff!
Normally if piston seals fail or the piston comes off the rod, the oil pressure acting on the rod itself turns the cylinder into a one way displacement cylinder pushing the rod out, albeit at a much reduced force due to the small size of the rod. Still with an empty bucket it should at least try to move. So yeah, either ice or some other blockage in a hydraulic line would be my first guess, followed by an issue in the loader valve itself.
The spool is the round shiny rod about 1" diameter that goes into the valve body and the linkage from the handle is connected to. See if it moves up and down the same distance as the one next to it. They should move in the range of 1/2", have the same spring pressure etc. Unless there's a solenoid attached to the bottom end, there will be a cover held on with a few small bolts or screws, you can take that off if the spool won't go down as far as the other one.
This might help ......... HeavyEquipmentForums
Thanks Delmer for the info. Know exactly what it is now, never knew what it was called. So I fired up the backhoe today, still cold, let it warm up for a bit. And presto, the cylinder/loader works as should. Must have been some ice I there somewhere or something. I believe the ice issue was in the valve control/body, seems to move much further today which allows the bucket to curl. Guess I jumped the gun and shoulda waited. Thanks for everyone's replies and help!
If, in fact, you had water in the spool cap, which froze and prevented movement of the spool temporarily until the machine warmed up and melted the ice, all that means is you still have water inside that cap, you might want to remove the cap and check out the internals, water will rust the centering spring and corrode (oxidize) the cap if it's aluminum, it'll get all sorts of messy inside there.