when do you toss a cylinder?

[daugen]

I have little experience with hydraulic cylinders, other than what I read in the Northern Tools catalog. Never had one break before.
And now on my new bucket/grapple, one of the two small upper cylinders is leaking nicely. Could well be operator abuse so I'm keeping an open mind.
Though the implement is seriously heavy duty otherwise.

What breaks on cylinders? Bending the rod? Pushing out an end seal?
Easily could have been some side pressures applied.
Just curious; headed in for warranty repair next week.
It's a small cylinder but hard to see in there due to the covers on top.

Are these things normally repairable, or if say the rod is bent, they head to get recycled?
thanks
Drew

 

[DT86]

Thats a bummer!

I've never messed one up so bad that it couldn't be fixed with the proper parts... Yet at least.

 

[BIG DOOLEY]

I have little experience with hydraulic cylinders, other than what I read in the Northern Tools catalog. Never had one break before.
And now on my new bucket/grapple, one of the two small upper cylinders is leaking nicely. Could well be operator abuse so I'm keeping an open mind.
Though the implement is seriously heavy duty otherwise.

What breaks on cylinders? Bending the rod? Pushing out an end seal?
Easily could have been some side pressures applied.
Just curious; headed in for warranty repair next week.
It's a small cylinder but hard to see in there due to the covers on top.

Are these things normally repairable, or if say the rod is bent, they head to get recycled?
thanks
Drew

should be able to get a seal kit.
disassemble and inspect the shaft for scratches, gouges and straightness.
you may find a bad seal when you inspect
if you have acces to a lathe you could have it spun and look for runout.
no lathe
find an extremely flat surface and have someone hold a light behind it. roll on the flat surface and look for light on the bottom where it meets the flat surface as you roll it.
use small feeler gauges and try to pass between the flat surface and the shaft at different locations as you roll into different positions .
Maybe you have a pressure relief/bypass too high for the cylinder rating?

 

[wdchyd]

A machine is only as good as it's weakest part.....guess you found it

Before you send it in for warranty repairs, do yourself a favor.......with the cyl off the equipment, pull the rod all the way out, then rotate the rod (to see if it's bent), then see if the rod is wiggling in the gland (to see if the gland is sloppy or egged out)

If the rod is bent or gland is not snug then the seals will blow out, guaranteed.......then time for a new one

While you have it out, check for cyl stroke travel......the cyl shouldn't be pushing around corners (if a stick gets in there and the cyl binds when extending the rod will bend)

 

[texasjohn]

Can't see how picking up those wood pieces would abuse the grapple. Yep, it leaks. At least it is a discrete part that can be dealt with without too much disassembly.

To answer your question, there are people who repair all sorts of hydraulic cylinders. Everything can be replaced, rods, glands, etc...it is just a matter of material cost, labor cost and time to accomplish. Sometimes, for a standard size, it's just more cost effective to replace. All depends. This should be covered by warranty, I would anticipate.

 

[daugen]

I kind of suspect either repair/replacement to the cylinder will be covered this time. But when closing the grapple fingers, the distance between the individual fingers is sometimes the size of the log round, and things get stuck.
Trying to "rub" them off on other wood is likely the cause of this damage, or possible just getting pushed on from the wrong direction. I've picked up some logs that taxed the capacity of the FEL and the grapple could barely hang on to the log. Am also thinking that those "stressful moments" might have contributed, but this is all speculation.

The cylinder is fairly short. There is only so much room under that cover. So going larger isn't likely an option. Are tie rod style cylinders stronger? Are US made cylinders better? (no HF cylinder is going on my Kubota...)
Also wondered if it wouldn't be a good idea to change out those hydraulic lines to armored ones, or at least put a protective cover over the oem lines. Lots of sticks and other sharp things, multiflora rose, getting in that area.
Would the electronics style plastic covers, the "twirly" ones that spread apart, would they be useful here?

Since 4shorts only plays in snow with his Kubota, he's probably the wrong person to ask, but if anyone has replaced those lines to "improve them", he likely has.
Visions of hydraulic oil spraying over the windshield have me wondering...
At the moment I have a slow leak that doesn't seem to be getting worse.

 

[Gary Fowler]

Those small cylinders are rather cheap to replace. I would just buy a new one, or take the old one off myself and get a new one from the dealer if it is warranty. Doesnt look like enough of a job to have to haul the tractor in for repair.

 

[daugen]

Those small cylinders are rather cheap to replace. I would just buy a new one, or take the old one off myself and get a new one from the dealer if it is warranty. Doesnt look like enough of a job to have to haul the tractor in for repair.

Agreed. Since the tractor had to go back for another hydraulic pressure test, we are combining a few issues. Dealer isn't far away which is good and their rollback operator is a nice guy, plus this one is likely on the house.
They are also installing a "tilt" cylinder on my three point, so now I have top and tilt. While it's under warranty, I'll let them do most of the wrenching. But my time will come.

 

[texasjohn]

When you take a hydraulic line apart, you discover that it is numerous layers of tough stuff, including metal braiding. Sure, something COULD always catch stuff just wrong and mess a line up. However, I expect that thorns on bushes, etc. will not be a real problem. I'd wait and fix a problem when it actually occurs rather than fix something that isn't yet broke. That said, I don't have a grapple thus haven't faced the problem personally. Any extra armor, other than a metal cover, doesn't sound to me like it would be particularly effective in preventing problems...you are dealing with extremely powerful forces, hydraulic and diesel, so, best solution is to watch for things catching the lines while you are using the grapple.

 

[Willl]

Sure it's leaking at the seal ?

Maybe it's a leak at a hose fitting or the hose itself.