Cylinder Seals

[tuffytractor]

Been having trouble with leaking Cylinders, so I took them off to bring them home to re-work the cylinders.



Probably could have done it on site, but I wasn't sure what I would run into and I had the cylinder cap removal tool at home. ( Pin Spanner?) Schematic of Simple Hydraulic Circuit.


I was a little intimidated at first, but I thought how bad could it be?


So I tore them down, expecting to find a more sophisticated wiper or seal system.


But this is all there was. Split washers and O rings.



My work is close to an airport, so they support a big Hydraulic Industry, I'll see if I can replace the split washers as well, but my guess is the O-Ring rubber is what is causing the leaks. We'll see... I'll have to wait till Monday to find out.

[3RRL]

Tim,
It's getting scary how good you're getting at all that mechanical and hydraulic DIY stuff in all your recent posts. I know how good you are on your construction projects from past posts too.
Looks like you got a handle on the hydraulic repair ... no sweat for you.
Larry G. Better watch out for this guy!
Rob-

[GuglioLS]

Tim,

You have a good work area to tear down and rebuild those cylinders. I could not help notice that nice HUGE vice you have there to hold the cylinders while you take them apart.

Did you unscrew the piston from the rod? You will have to do that in order to slide the rod completely out so as to replace the internal o-rings and wiper seals that seal against the moving part of the rod:



Larry

[tuffytractor]

Larry,

Actually I think I must have had a lapse there, It hadn't occurred to me to replace those wipers and O Rings. I looked at the end of the rod expecting to see an Allen screw or something to allow the end of the rod to come off, but there was nothing I could ascertain to remove to get the end of the piston off. I hesitate to take a pipe wrench to it for fear of scoring the interior of the cylinder under operation. Is there a secret method to getting the end off. No Allen key that I can ascertain.


Maybe @ the step down for applying the pipe wrench?

[tuffytractor]

Finally pulled my head out, realized using the pipe wrench wouldn't be a good idea, because the piston could work its way out, during normal function. I must have missed it, figured I overlooked something crucial. So, pulled off the split ring and found the set screw that was there the whole time . Was able to unscrew it by hand, no need for the pipe wrench at all.



Now I can get to all the seals to totally rebuild the cylinder and hopefully do away with the leaks.

[3RRL]

I take it the groove in the threads on the rod is where the set screw resides when holding th cylinder piston in position then? It's a good thing you took those "O" rings and split rings off. You would think they could have put it where you considered putting the pipe wrench ... in open view. However, I'm sure they put it under the split ring to retain the set screw to keep it form unscrewing and scoring anything.
Rob-

[GuglioLS]

Tim,

Good going finding the hidden set screw, decided to thoroughly analyze the situation before taking a pipe wrench to it sure paid off.
Last year, I rebuilt two very large cylinders for my dozer. After taking them apart, I took them to a hydraulic shop where they honed the ID of the cylinder before replacing all the wipers o-rings and seals. What is the condition of the inside walls of the cylinder? maybe it's OK and all the leaks are due to lousy Chinese rubber o-rings? Either way you'll be saving a bundle doing most all that work yourself.


Larry

[tuffytractor]

I ended up getting the seal kits on my way out of town, which in turn made it so I had to do the rebuilds on the back of my trailer using lights.



Got them back on.... and what do you know, no leaks. Yahoooooo!

[3RRL]

Good job Tim.
I'll bet your happy about that.

[GuglioLS]

Great going Tim.

Amazing you found all the seals for that oddball Chinese metric cylinder at a local shop. That says allot about what they stock. Maybe post their name and number in the hydraulic section under the CHARTS & LINKS thread that you started?

Larry

[tuffytractor]

I'll go ahead an place this information in the CHARTS & LINKS section as well.

The Seal Connection
Isaac Cano (knows his stuff, he is the only one to talk with)
14308 Wicks Blvd.
San Leandro, CA 94577
877.301.7325
[e-mail]

Took him a couple of days to get the stuff together. Was about $120 for six complete sets (2 spares). I had to leave him the Gland (the part that screws into the top of the Cylinder) and the Piston. So plan on doing without for a while if you are going to order.

[red]

Tim with that new "non-chinese" O rings you may not be needing the rebuild/spare kit for a while. Thanks for sharing you took the mystery out of the hydraulic cylinders -Ed

Edit Tim I forgot to ask you how many hours did you have on your tractor?

[tuffytractor]

I was doing the 100 Hour service, thought I would do the cylinders instead of watching em leak. I just couldn't bear to see em leaking when I really started working. Maybe for the last 20 hours I noticed a little leak, but recently they had really started to be too serious to ignore.

[red]

Thanks Tim, I was hoping that you had many more hours on your machine before the loader started to leak on you. Just about got most of my leaks (tractor hydraulics) fixed at the 74hr mark. Now if I can only get the freaking LG-6 back hoe to stop leaking I be a happy camper. -Ed