we were levelling some dirt backwards & lost all loader functions, I'm not sure if the pump failed or? I topped off fluid, little low & bucket barely tilts back/forth but zero lift/lower. How to troubleshoot? Thanks
Hydraulic filter?
Check your hydraulic oil level first, but my money is on an almost stripped pump coupler. It will hold just enough to rock the bucket, but not more load than that? If the backhoe still works, I am wrong.
I'm assuming that the backhoe does not function as well. So if that's the case then like mitch504 said you probably have a stripped coupler. Good luck in getting it off with the loader down.
hoe isn't being used. i thought it might be control valve but that doesnt make sense. I can hoist the bucket out of the way to change the pump. I replaced the original pump a few yrs ago. I don't know why it would fail again. Thanks
well, the bucket tilt forward & back seems to work o.k.,& tge levelling cyl., seems to be working. i think it must be tge very worn & beginning to leak control spool valve. Can it be rebuilt or just replaced?
I don't think a worn spool valve would do this. Is the spool itself actually moving? does the control handle feel the same as it did before? I'd do some pressure tests before taking apart any valves that aren't obviously broken, but might try a few other tests first.
it acts like there is equal pressure holding the up/down cyl's in place, as if fluid is bypassing somewhere? tge control feels the same but is very worn.
Does the engine load up when you operate the bucket tilt to the end of the cylinder stroke? - as it normally would have? If not, It's possible the main relief valve has something stuck in it - holding it open. I still wouldn't overlook the possibility of the pump coupling slipping on the pump spline either.
i'll run it again tomorrow & check
tilting the bucket all the way down causes the engine to 'strain' (at the end of the stroke)the cylinders are retracted. With the bucket tilted up (the cyld's extended) no change in engine whatsoever.
I would check your hoses and hose routing. Has any of the hoses been replaced for bucket operation? Does the loader lift function as it should? You might have a piece of the hose on the inside of the one hose blocking the flow of oil in one direction.
hoses all need replacing [museum pieces for sure] Lift does not function at all, only the bucket works. Hoe is not being used & not attached. I replaced the pump in 2011& its just a helper on the farm, nothing very difficult
Check your main relief valve sounds like something is holding it open.
You said the hoe wasn't being used, is it hydraulically hooked up so you can check its functions? If the hoe functions and puts a load on the engine when cylinders are bottomed then the problem is probably not in the drive coupler or the main relief even though it is contained in the loader valve. If you take the main relief apart do not disturb the acorn nut settings, just remove the whole body and retrieve the spring and plunger internal to the loader valve. inspect the screen and clean it thoroughly the plunger has a very tiny orfice that if plugged will kill the whole hydraulic system, only once in all of them that I have worked on have I seen one that the screen came off and jammed the plunger open. As far as the cylinders I would do a simple heat test on them, have someone run the machine at high idle and hold the hoses with the loader valve in raise mode and after a few minutes if you have a cylinder problem the hoses to the leaky cylinder will start to warm up. Sometimes your senses will tell you as much as a fancy test instrument which most do not have access to, also test your loader bucket cylinders the same way, also the hydra leveling cylinder.
yeah, it just seems like the lift cyl's are 'stuck' & one side 'droops' lower than the other but the bucket will push off tge ground & raise the lift cyl's up a few inches. The hoe is not attached to tractor. A hose may have deteriorated into the system & clogged something, they are falling apart. Main relief is on loader controls? Thanks
1st i'm going to change hyd filter & maybe fluid. The gauge may not work & its been years, prolly need change every year.
Not against changing oil and filter but that is not a magic wand, make sure the oil you buy is the best quality as cheap brands can cause cylinder packing failure. All oils are not equal. Do the test that I described on the loader lifts, if the engine will dog down a bit rolling the bucket out till you release the lever it sounds like the pump is running. Let me know how the heat test goes on the loader lifts, once the system builds a little heat in the hydraulic oil if the valve is held whichever cylinder feed hoses warm up has an internal leak. In my time I have seen piston rod bolts break or completely back out.
o.k. will do the test today & let you know. Thanks
ok, I tested the hydraulics as per melbens directions & the 'port' lift cylinder lines do heat up significantly after less than 5min. No other lines exhibit this phenomenon.
What does "port" lift cylinder lines mean? Does that mean the lines on the left loader boom lift cylinder get warm? but not the right one? that would pretty much mean you'll be taking apart that cylinder to fix the issue, and that jives with the piston coming off from a shock while backdragging. maybe not even a shock, just worked the bolt loose?
yeah, operator's left side lift cylinder. port/starboard. Where is a good parts source?
If the left cylinder lines are getting hot find out whats wrong with it, it is probably a simple fix, possible broken bolt or screwed out.
o.k., i'll get it apart & let you know. Thanks!
I tested Exactly as you said & removed the affected cylinder, the bolt inside had come loose & fell off
Take to any reputable Hydraulics shop they will repair your cylinder or go to a equipment scrap yard and buy a used one. Doubtful the other side will be any better, would recommend pulling it for inspect too or may be back doing this shortly.
i had them worked on by a guy advertising on craigslist about 6yrs ago so maybe he didnt tighten it well? He did them right here & i 'helped'. I'm taking it to be serviced next week, i think it is rebuildable but the bolt was damaged slightly(threads need chased) & washer needs replacing. Thanks
If he had that piston off then, then I'd sure blame him for it coming off. I can't see anything from that cylinder, but I wouldn't hesitate to put it back together if you've looked it over and don't see any damage. It's not like you're using this over people working, or making your living with it.
yes, he had it all apart. i'll post some pics. i need some new lines made so i have to go to the service shop anyway, maybe i can get all the new O-rings & seals there plus a new washer & do it myself
I always clean and dry the threads on the bolt and clean and dry the rod threaded area, after installing the piston I put Red Loctite on the threaded areas and assemble, I never put them together without it.