Anyone ever rebuild a hydraulic cylinder?

[Bob Warner]

I seem to have a leak in my cylinder. I am getting hydraulic fluid leaking around the rod when pressure is applied and it runs down the rod onto the hot steel and guess what, FIRE!!!!!

I've been on fire before and did not really like it so I need to fix this thing.


I am guessing there is a seal gone bad but I have never disected a cylinder before. Anyone here do it? Any tricks? Any idea where to get parts?

[Mail4Tim]

Bob,

Over the years I?ve dealt with actuators that ranged from ?? bore w/ ?? stroke all the way up to about a 14? bore with several feet of stroke. They are all basically the same, only the parts get larger and heavier. The type of seal you will have is really dependent on who made the cylinder and what it?s intended purpose was. It could be as simple as a nicked O ring or a worn out gland seal. If you have the manufacturer model number then things should be a little easier. The best place to start is with a local hydraulic supply company. They would be your best source for information as well as parts. In fact if necessary most can even handle the rebuild for you. Cost again will depend on the make and model of the cylinder you own.

Tim

[Bob Warner]

Thanks Tim.

I am not one to heve things fixed if there is any way to fix it myself. Do you know if there is such a thng as a rebuildt kit?

My cylinder is a Prince tie rod cylinder, 5" cylinder and 2" ram. Would I have to go to Prince to get the rings or whatever or would any company have them?

Also, when you take these things apart, will they fall apart like my favorite watch did and I won't be able to get it back together or does it come apart in some kind of reasonable way?

Man, I wish I could fix that watch.

[Mail4Tim]

Bob,

If you have a half way decent suply shop they should have everything you need. Possibly pre-packaged as a kit, but if not they shoud be able to put one together.

As long as the cylinder shaft isn't damaged there is no reason to think that the rebuilt unit won't last. Like I said it could be as simple as changing an O ring.

The one thing I would caution. Check with the supply house before you tear the cylinder down. That way you can limit the time the cylinder is out of service. There is no reason to take it apart if they don't have the parts in stock.

Another note. When it comes time to reassemble everything I've found that a mixture of grease and STP oil treatment makes things go together a lot better. The grease by itself is too thick so the idea is to thin it down some with the STP. Think of it as a home made O ring lube. The biggest problem most people have is cutting an O ring when they try to re-assemble things. Having enough lube will help eliminate this problem.

Tim

[rhrocker]

Try the Surplus Center, they might have a kit (might not).

[Ron Claiborne]

Bob prince does have rebuild kits. for most of what they build
just be sure the ram is not bent and has no nicks ===or rust ==most are plated

[Sweany]

My buddy just got a seal kit for his backhoe from DitchWhich. Not a biggie if none of steel is nicked or worn out. Basic premise is to keep all dirt out of the cylinder when rebuilding it. Dirt and hydraluics don't get along. If you can't find one email me. We just started repping rebuild kits. I don't have much info on em yet but I can find out. sweanymd@yahoo.com

[severtecher]

I use Dow Corning DC-4 as a lube but if you just take your time and use the fluid the unit is rated for that is the only lube you need. Make sure to use the right fluid with a compatible "O" ring.

[BrianT]

Hi Bob

I have rebuilt more hydraulic cylinders than I can count. I have worked on hydraulic systems in the mining industry for 15 years.

Tie rod cylinders are the easiest to get apart, but they will fall apart when you take the bolts off.

A rebuild (repair) kit should fix it good as new. You may have to contact Prince or if you have a good hydraulic shop in your area, they should be able to get you the parts.

Some tips:

Hook hoses to the cylinder and put the other ends into a bucket. Pull the cylinder rod all the way out and push all the way in to get most or the oil out.

If the piston packing and/or gland seal are V or U shaped, the V should point away from the pressure of the oil. The oil pressure opens the V and creates a tighter seal between the cylinder wall and the piston.

Lube all O rings and packing with oil that you will use in the system. You can't use too much oil.

Slide the repacked piston into the clyinder carefully and gently wiggle as you go in.

Take the thing apart with the barrel end in a vise and the cylinder standing straight up. (For tie rod cylinders, less likely to fall apart)

Tighten the bolts evenly.

Dont force things. If you have to use a hammer to get things together, you are probably cutting a seal. Things should be tight, but they should go together.

Hope this helps
Brian

[Bob Warner]

I hope to get to this fairly soon but things keep coming up. I am now looking for the rebuild kit. What should I expect to pay?

[BrianT]

Bob

If your rod size is 2" and your piston size (bore)is 5", $25.00.

Try this site, you may find what you need here.
http://www.epm.com/prince.htm

Brian