I pulled the center cylinder to rebuild (3 stage Cascade mast). It was leaking pretty bad through the end cap. When I disassembled, the oil that came out was brown and rusty looking. This machine sits quite often, it lives at an off site building. There was lots of fine rust behind the cap seals. I need to look for a hydraulic filter, as it should be replaced as well as the hydraulic oil.

I have three questions that I was hoping someone could help with.

1. Is it normal for there to be this much rust in these cylinders?

2. What grade hydraulic oil do these require? I have lots of 30weight on hand.

3. What filters should be cleaned or replaced in the hydraulic system?