press jack leakage - normal?

T

TRX

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I have one of the popular Harbor Freight 12-ton shop presses. It's a simple tool, but every few years the hydraulic jack begins to seep oil and eventually fails.

I release the valve, let the springs pull the jack closed, up against the crossbar, then close the valve. The springs put continuous pressure on the jack, but it's probably in the 20-30 pound range. Is this the likely problem, or are the seals on the Chinese jacks just bad?
 
When you say "seep oil", from where is this oil exiting? Most of these Chinese jacks use O rings for seals and I would imagine they are not of the highest quality simply to keep cost cheap. If the jack is fully collapsed I doubt the spring pressure has much, if any, affect on this condition.
 
I've found with the "S.E. Asian" hydraulic jacks and auto jacks I've opened for leak repairs, the barrels are comparatively rough as to the honed barrel one would expect to find in a quality product. O.E.M. seal quality is unknown, but certainly the barrel roughness contributes to seal wear. The seals [metric from what I've seen] aren't expensive, and you'll get a few years out of new ones. Talk to a local hydraulic shop about replacements. If possible, a honing to smooth up the barrel would help. The rods on the jacks I've seen aren't chromed and polished as one would find on better stuff, hard on the rod seals. This isn't all bad, I have some too; have to weigh out the cost vs. benefit difference.
 
In my view, if it's for a shop press or something non-life-critical, live with it and don't use for anything else or buy a different one. They are cheap enough.

If it's for critical applications that could cost someone life/death. Strip it for parts, make ornaments out of the rest -what little remains ends-up at the recycling dump.



TRX said:
I have one of the popular Harbor Freight 12-ton shop presses. It's a simple tool, but every few years the hydraulic jack begins to seep oil and eventually fails.

I release the valve, let the springs pull the jack closed, up against the crossbar, then close the valve. The springs put continuous pressure on the jack, but it's probably in the 20-30 pound range. Is this the likely problem, or are the seals on the Chinese jacks just bad?
Click to expand...
 
I don't know where the oil is coming from. I might use the press once every six months. When I move the stuff aside to get to it, eventually I'll find an oily mess and a dead jack.
 
I kind of think its normal. Mine started around six months old. We press a lot= things come in
bunches, last week was transaxle week. My solution, we stuck a air over hydraulic 20 ton
with a foot control. Works slick as ice.
 
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