Good morning, Still have trouble with lift arm not lowering all the way. After rest, it will operate normally (full range of motion, smooth) for awhile. Then the right side hydraulics create a hard stop a foot above fully lowered. You can see that right side binds, and if you mashed the peddle you may be able to twist the boom. Not good. Should I be looking at a cylinder rebuild or valve problems? It first started when I left arm fully raised for a couple days and the stop occurred at approx 6 foot above ground. Thanks!!!!
Possible air bubble? Is there any play in the boom arms maybe it is loose at the bins and getting caught?
Don't think it's pins. It stopped at different positions. If I go out this morning, it will have perfect range of motion after it leaks down. Could be wrong, but stop does not compress like air. Think it's hitting oil that is bypassing a seal someplace. Has something to do with right side lift cylinder. Appreciate your inputs and thoughts. Would be nice to take out correct part first ;-) If cylinder, do you typically rebuild one or assume both will wear out at same time?
HeavyEquipmentForums THat's the original thread with background. I can't make sense of it. I'd chain up the boom and take the upper pin out of both cylinders, strap them up so they're mostly vertical but can extend all the way without hitting anything, then start it up and see if they operate smoothly for the whole stroke. They won't go at the same rate all the time, one might close all the way, before the other starts etc. that's fine. You just want to see that they operate. If the cylinders operate disconnected from the boom, then examine the boom a little more to see what kind of force is being put on that cylinder to make it bind?
Thanks Delmer. It really helps thinking this thru. Will let you know what I find. If it's not a binding problem, I'm expecting the right cylinder to not fully return after about 10 minutes of operation. Troubleshooting section of manual seems to mention everything but my problem. Schematics are not clear but I see references to Loader Arm Cylinders. Can I assume that same hydraulic circuit serves both sides? That seems to indicate cylinder is problem, and not Main Control Valve. Again, thanks for helping me think! New territory and it's easy to get squished...
You can follow the hoses from the cylinders, they should tee together and go back to the control valve. I've never seen anything like this where these two cylinders aren't connected to the same plumbing circuit.
Just spitballing here....could the right cylinder have a nut back off and loose laying in the barrel allowing the piston in make contact? Wouldn't account for binding 10-12" from bottom but heck empty one side would lift, piston could be wedged in sideways even if it came apart. To me linkage issues would be fairly easy to spot, perhaps there's an issue in the cylinder. Just a thought. Could be right, could be wrong. It's happened before! Good luck! Junkyard
OK. I Unhooked rod end. Left one slides in and out fine. Right one sits there like a lump. Can I safely assume that seals failed and binding caused by fluid passing to other side and creating a block for good cylinder? Plan is to remove offending part and bring to shop for new seal kit. So far I have not smashed anything and have all my fingers. Thanks for all the help!
Is that under power, or by hand?
You made my day. Wish I could push those cylinders by hand. Then I could do my digging without a machine ;-) Raised arms a couple feet and blocked. Then removed pin from front end and let cylinder hang in a sling (hoses still connected). Started machine and was able to observe full range of motion on good side. The bad side retracted and not much happened after that. Will try to find a shop tomorrow that should be able to tell pretty quick if seals or line blocked. Stay tuned. Will post exciting conclusion to the story ASAP...
If the piston was bad, I'd expect it to extend with the valve moved either way, but not retract. I guess you'll find out, when they test the cylinder, and I'd ask that they test it before tearing apart. The real odd part is that it first stuck extended, and now it sticks retracted. I suppose anything is possible with junk floating around in there, or the piston loose and jamming?