Hydraulic Cylinder locked up

Ok the new guy has another stupid question. Do hydraulic cylinders lock up? I took one end of each cylinder loose from the machine to try and flush as much oil as I could before changing. One of the cylinders that raises the arms will not move. With a come along and both hoses off it will not move. The arms were going up and down before I started this project.

They should never lock up, but if the rod is bent it can bind. It shouldn't take that much force to move it, they should be tight, but you can generally move them by hand.
You may need to pull it apart and find out what the issue is.

Tazza said:

They should never lock up, but if the rod is bent it can bind. It shouldn't take that much force to move it, they should be tight, but you can generally move them by hand.
You may need to pull it apart and find out what the issue is.

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Tazza, I took it off the machine and could push it back in but it was hard. I put it back on for now because I got bigger problems. I was thinking there might be a check valve in it somewhere.

Hermit said:

Tazza, I took it off the machine and could push it back in but it was hard. I put it back on for now because I got bigger problems. I was thinking there might be a check valve in it somewhere.

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That sounds like how the cylinder should be. The rod should be quite firm, when worn they slide a lot easier, but that allows oil to by-pass internally.