Posted by Randy On Long Island [108.162.219.114] on Saturday, November 19, 2016 at 16:18:14 :
In Reply to: Re: Hydraulic jacks posted by Terry [199.27.133.57] on Saturday, November 19, 2016 at 14:18:18 :
I once bought a Chinese floor jack at auction; new..never used. Being relatively light and compact I figured it might come in handy. First time out it failed. Rapid leak-down. Upon inspection I noticed a score down the side if the plunger/cup. It matched up to about a 1/8" diameter hole drilled in wall of the cylinder. Possibly a relief or return port, don't really know. However, there was a burr there that scored the plunger first time it went past it. Went to a repair shop to get a new one and the guy showed me 6 or 8 similar defective plungers lined up on the window sill. Said they were metric sized and not available. Figuring I had nothing to lose; I cleaned up the old plunger with lacquer thinner, filled in the score with silicone gasket sealer, removed the cylinder burr, and reassembled. Now, many years later, it leaks down very slowly and can be used in a pinch. Just can't work under it without jack stands...which one shouldn't be doing in the first place.
Note: I also have an old Sears floor jack of about the same vintage.