I'm posting this in the NorCal forum because I'm not shipping it to anyone - it's not worth it.
I have an AC Delco "3 ton" SUV jack like this one:
Except the piston or seal seems to have failed and it will no longer reliably lift a load. You either need to order a replacement hydraulic piston from AC Delco or rebuild it yourself. High end jacks can be rebuilt. Not sure about cheapies like this one.
I'll give it to the first person who can take it off my hands, basically you have to pick it up from me in person in San Jose or at work in Mountain View, or possibly at Jerry's mod day in May.