580k hydraulic cylinder rebuild, getting rod back in the cylinder...

case310350 · Apr 2, 2021

I normally have the shop rebuild cylinders, but now they want 500-850 to rebuild, doe not include the kit.
So doing myself.

Now I repacked the cylinder, but ripped the seal on the piston while putting back in the cylinder. The seal is not split, its one piece and sticks out beyond the piston profile. .

Looking for advice, or tricks to get it back in. right now I have a hose clamp on it, will leave over night.

398370 · Apr 2, 2021

Send pictures. Will tell if screwed or not

BigWrench55 · Apr 2, 2021

On cylinders that I am having trouble getting back together. I use a ring squeezer to compress the seal. You can pick up a cheap one from any auto parts store.

alrman · Apr 2, 2021

Yes, also known as a piston ring compressor.

Jonas302 · Apr 2, 2021

Of course replace the ripped seal if its mission critical I like to have two of everything on hand

Find a way to put even controllable light pressure on the rod like a ratchet strap so you can wiggle and work it in lots of times with that kind of seal you have to work the lip with a butter knife type tool

willie59 · Apr 2, 2021

It also helps to have things warm, cold seals aren't very flexible or elastic. In cold weather I hold components, such as piston seals once I've fitted it on the piston, in front of an oil fired space heater for a few moments to heat them up, then put the ring compressor on them to make them compress back after being stretched onto the piston during fitment. Once that's done, heat the piston assembly for a few moments, plenty of assembly grease inside the cylinder can and on the piston, then slip the piston inside the cylinder.

Coy Lancaster · Apr 3, 2021

I always put a screw type hose clamp around the piston seal and let it sit for a bit before installing, and then I grease the crap out of it and the threads on the gland.

melben · Apr 3, 2021

Coy Lancaster said:
I always put a screw type hose clamp around the piston seal and let it sit for a bit before installing, and then I grease the crap out of it and the threads on the gland.

I do as Coy does but wrap a few wraps of electrical tape on the seal before putting the clamp on, i do not want the metal parts of the clamp imprinting the seal. Leaving the clamp on for a few minutes, after removing it and the tape the piston will slide right in.

case310350 · Apr 3, 2021

what type of grease do you use so it does not contaminate the oil? The ring clamp tool won;t let the rod go in far enough for it to work.

Tinkerer · Apr 3, 2021

I sometimes cut a section out of a 1 gallon milk jug and lay it in the barrel threads to protect the piston seals until they are in.
I always slather hyd oil on the piston.

Swetz · Apr 3, 2021

We always used Vaseline (petroleum jell), and as you can imagine there were plenty of jokes to be had, but it is supposedly compatible with the fluid once warmed during operation.

Make sure the lead in the cylinder barrel is shiny clean. A little rust make it grab. The come a long strap and wiggle is often productive.

Tinkerers milk jug method may also be helpful...we used to use shim stock when necessary on some designs.

John C. · Apr 3, 2021

case310350 said:
what type of grease do you use so it does not contaminate the oil? The ring clamp tool won;t let the rod go in far enough for it to work.

You take the clamp off before trying to insert the piston in the barrel. The key to assembling it is to make sure the rod is straight to the barrel. I've stood the barrel up on end and used an overhead crane to drop the rod into the barrel if I had the room and lift. If I had to do one on the floor, I tied the barrel down and blocked the rod to the level of the barrel and had to use a hammer or fork lift to put them together. The packing glands have always been the biggest problems for me. When they went to high pressure systems and multiple pieces of packing in the gland, it got hard to push the gland onto the rod. A few times I've been dismayed to see a sliver of packing show up on the rod as the gland was pushed up.

Coy Lancaster · Apr 3, 2021

I always used whatever grease you use to lube your pins n bushings. The type clamp I use is for silicone hoses, they won’t leave marks on seal.
Put clamp on seal after installing let set for a few minutes then remove clamp grease piston and install.

melben · Apr 3, 2021

I have done hundreds of Case cylinders in my 52 yrs and the tape and clamp method is by far the best , the idea of the clamp is to reform the seal to it's original size after stretching it on the piston. A little HY Tran on the packing and they slide in easily, I do that method on power brake pistons in brake valves that use a square ring expanded by an oring as small as 5/8 boost pistons in Case ag tractor valves using the real small fuel hose size clamps.

Swetz · Apr 3, 2021

Coy,
Is this the one you are referring to in your post? Called a T-Bolt clamp.

melben · Apr 3, 2021

Swetz said:
Coy,
Is this the one you are referring to in your post? Called a T-Bolt clamp.

I use standard radiator hose clamps but that is ideal, much nicer than what I use, I probably would use electrical tape anyway but it may not be necessary.

Swetz · Apr 3, 2021

I have typically used either a piston ring compressor or appropriately sized gland bearing/guide ring with a worm clamp around that. The t-bolt clamp seems like a good idea.

case310350 · Apr 3, 2021

after using a hose clamp overnight, the piston slipped right in, almost too easy.... Now need to do the boom cylinder. I do have the adjustable gland nut wrench which so far has proven useless. Had to make a tool for the lift cylinders. Thought I would ask is there a technique to using this? slips off easily. I wedged a block of wood to hold the tool in place, Looks like I have to make another tool for the boom gland nut... Thanks for the help, I did use vasoline for the lubricant, they use it for automatic transmission assemble so figure it was the best option.

case310350 · Apr 3, 2021

the boom cylinder piston cap screw is 1300 to 1600 ft/lbs. Don't think I can get that off so looks like I will be spending some big bucks to get this one done. Unless there is a trick I do not know about. I do not have a torque multiplier anymore.

Coy Lancaster · Apr 3, 2021

Swetz said:
Coy,
Is this the one you are referring to in your post? Called a T-Bolt clamp.
Remember all you’re doing is compressing the seal down where it will fit in the tube.

Those will work if you can find one big enough. The ones I used were screw clamps.

580k hydraulic cylinder rebuild, getting rod back in the cylinder...

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