Check out Otto Service,
http://www.hyjacks.com/ has a lot of basic jack info. on his web site and sells repair kits as well. You might consider a seal repair kit for your jack. Either the Otto site or another one I read last year when I was repairing mine says these Chinese jacks are only good for an average of 10 uses before the seal starts to leak. I have an old Walker 4-ton that I paid $25.00 for in the late '60s and it looked worn out then. Last year I paid more for a seal kit for it than a new Jack cost at Sears. But it lifts 24 inches and I don't expect to ever have to buy another jack.
