I got an old hydraulic jack. It is 10" high, 4.5" diameter, with a 2"
piston. It is obvious that it has sat for a long time. It had some mud on
the outside. Jack oil runs out the fill plug, and when I remove the turn
screw, jack oil comes out the bottom. The pump pumps out the piston, but
only a short way, then the pump becomes easy, leading me to believe it is
low on oil. BTW, how much oil do I put in there? Up to the fill hole?

Should I just put some jack oil in there, or is there a process to flush,
which may take out any water in there? Would some Marvel Mystery Oil harm
the seals? Would there be another fluid to flush it with? Or should I just
fill it with oil and call it good?

This appears to be an older one, not Chinese. Are these rebuildable? Out
scrounging for cribbing for a new container, and found a volume tank for a
compressor, too. Think I'll make a portable air tank out of that.

I love to go scrounging. Took my 86 yr. FIL, and he's just a big kid when
it comes to puttering and scrounging.

Steve