I have a friend that is a heavy mechanic instructor, and he tells me that it is well within most anyone's ability to do it yourself. You remove all the nonmetallic bits, put them in a sandwich bag, and take it to any one of the hydraulic places in town. Reinstall is just as easy. A huge number of 'rebuild hydraulic cylinder' vids on the 'tube. -- Sorry I'm not ready do do mine or I could give you a personal account and recommendation.
- I have 3 engine hoist cylinder/pumps to rebuild and a 10,000 PSI portapac/reservoir to rebuild - when I get better again, and I have gotten some of the A list things done that went on hold. Then I could name a supplier and give a review.