Hoping to get some pointers from those of you that have changed the seals on your cylinders. I have an earlier model 580C that has the 2 piece pistons. Unfortunately I found this out the hard way- I initially bought a one piece piston kit for the loader lift cylinder, and realized after it was apart that I needed a 2 piece kit. So I changed the seals in the gland nut and put it back together. But there are a few other leaking cylinders that need to be fixed. Here are my questions: 1- Is it easy to figure out which seal goes where? I can't seem to find any diagrams or instructions anywhere. There seem to be a ton of seals that all stack up. I want to make sure I put them on the right way. The only thing I've found that helps a little is the photo below. 2- I think I might have put the gland nut wiper seal on backwards. Does the flat/metal part rest against the gland nut or does it face away from it. I'm thinking that the side of the wiper seal with the recessed area is supposed to face away from the gland nut. 3- putting the piston back in the cylinder was way harder than I would have expected. Is there any sort of lube that might make this easier? I just put hydraulic fluid over it but maybe there's something better? I've heard some people say to use vaseline but I'm not sure if that's a good idea. I appreciate the help!
Parts books are your friend ! Here is an example of a 580C swing cylinder with a two piece piston. You should look up the particular one you are working on.
Thanks for the photo! I bought an owners manual and repair manual on eBay in PDF form but it's not the clearest. I'm guessing it was a scan of an original manual. It seems like there are multiple seals that go on either side of the split piston. My main concern is that some might be beveled and I won't know which direction to put them in. Of course I can just be careful not to mix them up when I remove them but they'll probably be very worn.
The details on how to stack the piston seals is on page 4090-8. Take photos of the old seals as you separate the cylinder assembly. Unless you but an OEM paper service manual you are only going to find scanned copies of an original. Some are better than others.
Speaking in general terms, most seals will have a "flare" to them on their OD or ID. It usually flares out on the side with the groove. As you push directly on the flare, it gets pressed tighter and seals tighter. So on the seal that you can see outside on the gland nut when it's all put together, the flare should point out. This is because this seal is there to keep dirt and water out of the cylinder. So when the cylinder retracts, and water and dirt try to get in, the seal is pushed tighter and seals against the dirt and water. But in this same gland, you have another seal on the inside of the gland you cannot see when it's together. This is the high pressure oil side of the gland. The flare on this seal should point in toward the center of the cylinder. You want to keep the oil in the cylinder, so when the oil pressure rises, it presses harder on the flare of the seal and makes it seal even better.
Thanks for the replies. I had the wiper seal on correctly but I might have put the hard rubber seal on backwards. I found the following photo which shows the correct orientation of each. The wider/flared part of the seal should be facing the piston. Not sure I installed it that way. And thanks Tinkerer for the page in the repair manual. I'll check it out.
I just wanted to update this thread in case anyone else came along that needed help. Attached is 4090-8 from the service manual (Thanks Tinkerer!). This is exactly what I was looking for. The page does an excellent job of showing the orientation of all the seals on the 2 piece piston.