Did I bust something on the loader hydraulics?
- Thread starter JCoastie
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JWR
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bdhsfz6 is on the right track. You do not catch a long pole/log against a tree on one side and create extra air in cylinders, valve body issues, pumps, tire pressure changes or any of the other wild ideas being posted.
Very simple. Exactly as bdhsfz6 said -- the OP "twisted the frame a bit." I have done the same thing using a MF2660 and DL250 loader (but a whole lot worse than an inch or two difference right and left) by abusing my machine trying to pry out a locust stump with one corner of the bucket. I've posted this several times. A wise shop man at my dealer said "you never heard this from me, but if you sprung it one way you can spring it the other way." I did and untwisted the loader frame. People should be aware that there are no specs of any kind on loader torque or twisting. The National Tractor Testing lab in Nebraska has no data on the topic and does not test for it. The mfrs position is "Don't do things that twist it. And if you do it is your problem." bdhsfz6's 2x8 solution is about as good as any. That really won't "untwist" it but it will take advantage of all the slop you can gain by loosening and retightening the loader frame mounting bolts. Since you have a relatively small amount of "spindling" or "twist" that'll probably take care of most of it. Then there is the Thousand dollar solution: take it to an automotive frame straightening shop (harder to find now than ever before) and they will straighten it at least as good or better than it came from the factory measurement-wise. Might be good to get an estimate if you have a bog body shop nearby.
The way you accomplished your twist, you have no realistic way to "untwist it" or cause directly opposite force in the opposite direction. If it is low on one side, you could try catching the far other side tip edge of the bucket under something solid and then put all the force you can on it in the opposite direction of the twist. I doubt you have a strong enough tractor to do that. It took momentum to create the problem and there is no reasonable way to suggest you try momentum in the other direction.
Caution: FIRST check every weld everywhere on the entire loader frame. Twice. Make sure none are broken or paint crinkled. Also use a long straight edge like a 4 foot metal ruler and check along the arms and flat surfaces and see if there is any detectable bend. That won't fix it but it will be entertaining.
RancherGuy
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Hmm. I'm not convinced the problem is what is commonly called a "tweaked loader". I did that to one one my loaders, and the only symptom was the bucket left side was lower than the right when placed on the ground. Mine was very visibly obvious. There was no change in cylinder behavior.
The OP's video shows that all four cylinders change length with just the pressure/weight of his footstep. To me, cylinder movement is a hydraulic system issue. If all cylinders are fully extended and retracted to purge possible air (wish he would respond with a confirmation), I would then consider that the joystick valve block has damage. That damage would be internal check valve(s) not doing their job.
JWR
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Good point. I had glossed over the issue of the cylinders moving. I thought someone else said that was normal ??
Unless you have a crossover relief valve on your FEL, I would guess you damaged the internal parts of the cylinders. When the valve was in the neutral position and you hit the tree, it created a large pressure spike in the closed part of the hydraulic system that consists of the cylinders and hoses up to the point where they connect to the valve. Since the valve was in the neutral position, there is no relief on the cylinder and hoses. That's why for things like snow blades where there is likely to be a large differential force on one side of the blade that gets transmitted to that cylinder, they always install a crossover relief. I personally think there should be a crossover relief on all FELs just to address the issue you just had.
I'm not sure I can explain that excessive rod movement in your video. I could imagine the hydraulics on one side of the bucket being damaged by hitting the tree, but not the other side. Unless the long trunk you were carrying acted like a lever arm that tried to force one cylinder into retraction and the other cylinder into extension. That would damage both cylinders and could result in the excessive play you see. It's also possible the force was so large that both rods are slightly bent, maybe not enough for you to easily see it, but more than enough to allow oil to pass by. It is still puzzling that the rods move freely in the retract position. This should not be possible even if the seals are completely destroyed, so maybe there's something going on internally that I haven't' thought of.
I'm not sure I can explain that excessive rod movement in your video. I could imagine the hydraulics on one side of the bucket being damaged by hitting the tree, but not the other side. Unless the long trunk you were carrying acted like a lever arm that tried to force one cylinder into retraction and the other cylinder into extension. That would damage both cylinders and could result in the excessive play you see. It's also possible the force was so large that both rods are slightly bent, maybe not enough for you to easily see it, but more than enough to allow oil to pass by. It is still puzzling that the rods move freely in the retract position. This should not be possible even if the seals are completely destroyed, so maybe there's something going on internally that I haven't' thought of.
npalen
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This has to be one of the most frustrating and ill informed threads I've ever read on TBN! Anyone else feel the same? 
Edit: Not directed at anyone in particular.
Edit: Not directed at anyone in particular.
JWR
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Didn't the OP say that everything about the loader works normally except that it sits low on one side ??
Tx Jim
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This has to be one of the most frustrating and ill informed threads I've ever read on TBN! Anyone else feel the same?
Edit: Not directed at anyone in particular.
Unless JCoastie decides to reply again nobody will know the correct answer.joea99
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Well, I'm late to this party and certainly no hydraulics expert. But.
The video seems to show the bucket being rocked, just by foot pressure, with the bucket and the entire FEL frame raising and lowering in sync. Did not see anything indicating this was while running, shutdown, or what position the FEL control might be in.
While I am not the heaviest guy around, I cannot do that with my little B21 and I doubt that machine is any lighter. Pushing or extending ONE cylinder takes more effort than that, let alone FOUR. Along with the weight of the frame itself? Am I missing something? A few marbles here and there not counting?
