Need advice on how to disassemble hydraulic cylinder

[timsch]

I've removed one of the L275DT tractor's FEL lift cylinders to replace the seals.

I thought that the cap with the flats holding the rod in would thread off, but it just spins in place. There appears to be a retainer piece, similar to the bent wire types that press into grooves, but I can't tell for sure. Can anyone tell me how this comes apart? The cap rotates freely within the cylinder.

I thought maybe the wire(?) down in the cylinder groove was some kind of spring retainer that should be depressed for rod cap removal, but it doesn't budge when I press down on it through the groove with a screwdriver.

 

[#40Fan]

You need to spin that wire until you see an opening. Then spread it apart.

 

[timsch]

You need to spin that wire until you see an opening. Then spread it apart.

OK, I got the wire to move. The gap is shown now in this picture.

I wasn't able to get any spread at all with my small circlip pliers, which were the only ones that fit. I'll have to grind my large circlip pliers to be able to fit if this is the way it's supposed to be done.

When it is spread enough, are the cap and rod supposed to just slide out? Does the clip stay captured in the cylinder?

 

[North Idaho Wolfman]

You have to pull the retainer out of the slot.
One side should be sort of a hook end.

 

[Magicman]

Keep turning the end toward you and the spring/keeper will emerge from the slot. Keep turning until you can remove it and the end will now tap off. The seal kit should have a new spring/keeper. If not, reuse the old one.

 

[timsch]

Keep turning the end toward you and the spring/keeper will emerge from the slot. Keep turning until you can remove it and the end will now tap off. The seal kit should have a new spring/keeper. If not, reuse the old one.

Thanks everyone for the advice.

I've pushed the opposite end of the keeper as far around in the slot as possible. I've turning the end cap, but this does not move the keeper any further. I also bent up the exposed end slightly and tried to tap it out by clamping a vice-grip on the end and tapping the VG with a hammer. Didn't move.

 

[Magicman]

You are not going to tap the keeper spring out because of the secured other end. You must turn the end cap on the cylinder which will cause the keeper to extrude from the cylinder. After you go all of the way around, you can twist and disconnect the other end of the keeper. Then the cylinder end cap will come off.

 

[Magicman]

Looking at the above picture, turn the left end upward and away from you which will cause the keeper to be ejected through the hole as the end is rotated. Notice that the bottom of the slot is beveled which helps the keeper to be ejected.

I do not have any pictures of that particular type if cylinder but I have rebuilt several.

 

[timsch]

Thanks for the guidance. It finally came out. I rotated the cap counterclockwise a couple of rotations with no movement from the keeper, but then it caught and rotated partially out. I decided to reverse rotation to see if it would pull back in, but the cap just spun with no keeper movement. I changed direction again and got a couple of full rotations before the keeper caught and proceeded to come the rest of the way out.

Can you tell me from the picture whether this keeper is in the correct condition (other than the bent end that I did)? It doesn't seem right that I was able to freely rotate so many times without it moving.

 

[Magicman]

Congrats on getting it out.

No, your keeper is badly compromised. One end of the keeper should have a 90 degree bend which goes in a small hole and captures that end. Apparently that portion was broken off or at least straightened which allowed the end to turn without ejecting the keeper. My rebuild kits always have a new keeper.

 

[Pau7220]

Here you can see the square wire retainer, and how it is should work.

http://www.princehyd.com/portals/0/techFAQ/CylinderSquareWireRemovalInstallation.pdf

 

[Magicman]

Very good link!!

 

[The Evil Twin]

I only have this to contribute.

 

[timsch]

Congrats on getting it out.

No, your keeper is badly compromised. One end of the keeper should have a 90 degree bend which goes in a small hole and captures that end. Apparently that portion was broken off or at least straightened which allowed the end to turn without ejecting the keeper. My rebuild kits always have a new keeper.

I began this overhaul with the intention of removing the seals and taking them to a local specialty shop to match them, at the advice of a neighbor who is head and shoulders above my level when it comes to mechanical knowledge & experience with tractors. A rebuild kit would be preferable to me, but without knowing the model number of the FEL, I hadn't really considered one. Since you mention rebuild kits either as ones you put together or get somewhere, maybe you can point me to which kit would be right. What info would you need?

 

[timsch]

I only have this to contribute.

Funny, that's almost exactly how I got the keeper out....

 

[Magicman]

I hadn't really considered one. Since you mention rebuild kits either as ones you put together or get somewhere, maybe you can point me to which kit would be right. What info would you need?

Sorry but I can not help you with the rebuild kit source, but any rebuild shop should have everything including the keeper. You should be able to take the worn stuff to be matched.

All of my hydraulic cylinder rebuilds have been on my sawmill and the kits came from Wood-Mizer.

 

[Yooper]

Here are a few pictures of a cylinder I disassembled a few years back that uses the square ring.

 

[timsch]

I pulled the rod out and found an o-ring seal at the cap and what looks to be fiber or graphite packing. After seeing a few videos of cylinder rebuilds, I expected more seals, but I don't see anything else anywhere.

I haven't unscrewed the end piece with the packing, however - haven't even tried. It looks like it might be secured on there by some punches on the end to interfere with the threads. I'd guess that there are seals in there. Regardless, I will need to get it off to replace the packing. That being said, I'm not rebuilding them because they didn't work properly, but because they leaked out the o-ring seal at the cap. What would you do?

 

[PoTreeBoy]

I pulled the rod out and found an o-ring seal at the cap and what looks to be fiber or graphite packing. After seeing a few videos of cylinder rebuilds, I expected more seals, but I don't see anything else anywhere.

I haven't unscrewed the end piece with the packing, however - haven't even tried. It looks like it might be secured on there by some punches on the end to interfere with the threads. I'd guess that there are seals in there. Regardless, I will need to get it off to replace the packing. That being said, I'm not rebuilding them because they didn't work properly, but because they leaked out the o-ring seal at the cap. What would you do?



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Don't forget the rod seal and wiper in the cap. Where was it leaking?

Edit, you'll need to remove the piston to replace the rod seal and wiper.

 

[DustyRusty]

I pulled the rod out and found an o-ring seal at the cap and what looks to be fiber or graphite packing. After seeing a few videos of cylinder rebuilds, I expected more seals, but I don't see anything else anywhere.

I haven't unscrewed the end piece with the packing, however - haven't even tried. It looks like it might be secured on there by some punches on the end to interfere with the threads. I'd guess that there are seals in there. Regardless, I will need to get it off to replace the packing. That being said, I'm not rebuilding them because they didn't work properly, but because they leaked out the o-ring seal at the cap. What would you do?



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At this point, I would admit that I am over my head and don't have enough experience and then take it to a cylinder rebuilder and have them install the new parts and reassemble it. Keep in mind that if you don't get it correct the first time, all your time and money for parts will have been wasted. This is the type of job you are only going to do once and possibly never again. You gave it a good try, but now you are at a crossroads, and it is up to you to decide if you want to continue down the road with the repair or give it to the person that does this for a living and will get it correct the first time.