Repacking/rebuilding a cylinder

[chanceu]

I seem to keep trying to use my 12LA loader beyond its capability. After a few months use I apparently did something that made the bucket cylinders start to leak down. There was no fluid visible so it wasn't an external leak and when I finally took it to the dealer, they eventually repacked the cylinders. At first, they couldn't find anything, but after asking New Holland, they were told to check the cylinders and found the leak. It was fixed under warranty.

I have now done it again and I doubt they'll fix it under warranty again. I'm curious to know what's involved in repacking a cylinder? Is it simply replacing the seals? In my case, New Holland sells a kit (part #86643080) and I guess my real question is, is replacing the seals that come in this kit all that's involved in repacking the cylinder?

 

[kennyd]

Rebuilding cylinders is usually not a big deal. That said I do not think you are at fault, sounds like a manufacturing problem to me. There is no way lifting to much should damage your seals, the relief valve on the tractor should prevent that from happening from a safety standpoint. I would try to make a case at the dealer for them to fix this, or at the very least give you the seal kits free.

 

[texasjohn]

I agree with KennyD. Replace under warranty.

 

[Ranch_Hand_Supp]

Rebuilding cylinders is usually not a big deal. That said I do not think you are at fault, sounds like a manufacturing problem to me. There is no way lifting to much should damage your seals, the relief valve on the tractor should prevent that from happening from a safety standpoint. I would try to make a case at the dealer for them to fix this, or at the very least give you the seal kits free.

I agree ......... or either the pressure relief is INOP or set to high.??

Has any one checked pressure?

Something don't seam right to me.

Ronald
Ranch Hand Supply

 

[KJM]

No external leakage means the seal that runs along the rod is fine, internal means the seal against the cylinder wall is no longer sealing. Since operating the thing shouldn't cause a leak (modulo normal wear and tear) this probably means there is some scoring of the cylinders. Or a ridge/lip that is damaging the seals.

Sounds like the manufacturer is at fault, unless you have dirty fluid.

$0.02
/Kevin

 

[chanceu]

I agree that it shouldn't break as easily as it has, but both times it has, I had done the same thing. I used the edge of the bucket to scrape a couple inches of semi hard GA red clay forward and backward. I can't remember exactly what I did the first time, but this time I had the edge of the bucket tilted down and was pushing forward. The edge lost its "grip" then caught it again which let the bucket spring forward then get popped back. Sort of a crow hop. I knew when it happened it was broken again and sure enough the bucket started leaking down.

The leak is very slow so it wouldn't have to be much more than a small crack. I doubt there's any dirt in the fluid. The tractor has just under 100 hours. The first time this happened was around 40 hours and I had no problems before that. I did the 50 hour service which included changing the hydraulic fluid and the fluid was changed at least once that I saw when it was repaired a couple months ago. I can't say for sure, but I would like to believe if there was any damage or other problems with the cylinder the dealer would have taken care of it when it was repaired.

As for pressure relief, I don't know if there is one. The joystick doesn't have one and I haven't seen anything else that resembles a relief valve. Which means nothing except I haven't seen it.

 

[chanceu]

One other thing I tried just to verify it is one of both of the cylinders is to raise the loader then disconnect the quick connects. After doing this, the lift arms stayed in place and the bucket rolled forward. There were no visible leaks from the cylinders, fittings, hoses, or the quick connects.

 

[kennyd]

I still do not believe you should have been able to damage both cylinders by doing what you described. The relief valve should be on the tranny case or on the hydro pump, you DO have a relief valve somewhere in the system.

 

[chanceu]

Can't be a relief valve that is on the tractor side of the quick connects. The bucket leaks down with the quick connects disconnected and no fluid leaking. The fluid has to go somewhere and it isn't going on the ground.

 

[chanceu]

Even with the loader connected to the tractor, there is no fluid visible anywhere. I would think a relief valve popping would dump fluid somewhere under the tractor. I don't know that much about it, but I'm imagining something like a PT valve on a water heater where water is dumped until the pressure goes down.