Rotary swing cylinder repair?

[Arc weld]

I have a Cat backhoe on my 931B that has a leaking rotary swing cylinder. I know someone on here has repaired one off an MF backhoe in the past. I think they're at least a little bit similar. I've read the top o-ring leaking is common. Is it OK to just fix the o-ring or is it best to go through the whole thing? Other than the leak, it seems to work fine.

 

[Indygunworks]

Seals are cheap. If you are going to go through the hassle of pulling it apart, why NOT replace them all and have peace of mind?

 

[Recoveryhill]

Check your piston for any scoring which will eat new seals. I agree that if you're going to do "a" seal, do them all. If the piston is scored there are numerous machine shops that can polish and if it's too far gone for that, machine a new piston out of chrome bar stock for far less than the OEM price.