are there generic parts to fix hydraulic "jacks" valves?

[e9999]

I can get an older hydraulic table cart for free. It's reportedly a Harbor Freight one so not the greatest quality probably.
The problem is that the table doesn't stay up. It lowers itself fairly fast. I called HF and they say they don't sell seal kits for their tables for liability reasons. A new pump system will be about $90 for a current model but the cust service guy thought they may not fit older tables.

So my question is: are these piston and cylinders devices fairly standard and can one get generic parts to fix them, like seals? It's probably the valve seal that's bad I imagine. Or can I make a seal easily? I don't know what these things look like. Maybe an O-ring type seal? If so, maybe easy to find.

It'll be a pain to bring home so I'd rather know if there is a good chance I can fix it easily and cheaply before I do that. If not, probably not worth it. These things go for somewhere between $150 to $250 new at HF and probably would not buy a HF one new any way given likely quality issues and problem with parts. I don't need it badly in fact but thought it might be useful to work on my motorcycle.

Thoughts on likelihood of fixing the valve easily?

 

[Blue77FJ40]

Admittedly, it was a good while ago, I bought a bottle jack repair kit from this fellow. It doesn't look like he sells parts anymore, but maybe he can point you in the right direction.

http://www.hyjacks.net

 

[nuclearlemon]

just keep in mind what you are doing with the table and whether or not you want to risk failure. some of the seals can be very unique. i just rebuilt my floor jack and a couple of the seals i was not going to find in a generic kit.

have you thought of buying a quality cylinder, one that can be rebuilt later on if need be? when researching rebuilding my floor jack, i found people in the industry will say a cheap jack, even rebuilt, is only expected to get 10 cycles before it begins to leak.

 

[e9999]

well, got the table.

It is indeed slowly lowering itself. Still pretty useful but would be better otherwise of course. Finding a good jack that will match the fixtures would be a long shot I'm afraid, the cylinder base is not just flat. I've used a bottle jack to support the table from underneatch and that works, but that's a bit low and a clunky approach. But eh, it'll keep my bike up in the air so that's good.

Will take the valve apart and see what's up, to start with. Might be lucky, some basic cleaning might help or it may be standard o-rings for all I know. I'll practice first on some small bottle jacks I have.

 

[nuclearlemon]

So the jack.supports the table solely? I've got the hf motorcycle lift and its got a lock so the cylinder doesn't have to support everything.

 

[e9999]

So the jack.supports the table solely? I've got the hf motorcycle lift and its got a lock so the cylinder doesn't have to support everything.

yup, no lock that I've seen.
It looks exactly like a current Northern Tool 660lb model. The chromed one IIRC, but it may have been an HF model. But I may be able to score a rebuild kit from NT now since HF does not want to sell those.

 

[nuclearlemon]

yup, no lock that I've seen.
It looks exactly like a current Northern Tool 660lb model. The chromed one IIRC, but it may have been an HF model. But I may be able to score a rebuild kit from NT now since HF does not want to sell those.

this one? could you modify it to put a lock in? maybe drill holes on the rail that the roller slide in where you could put a pin in? without seeing in person, don't know how stout the channels are.

would take a hell of a lot of pressure (literally) off the cylinder

 

[e9999]

this one? could you modify it to put a lock in? maybe drill holes on the rail that the roller slide in where you could put a pin in? without seeing in person, don't know how stout the channels are.

would take a hell of a lot of pressure (literally) off the cylinder

similar table, different release valve system.
good thought on the lock. I could also just put a piece of straight steel tube or rod to hold the bottom rollers in place. easy and no drilling even. have a couple of different lengths and I have different heights. mmm.....

 

[pb4ugo]

I'm in the process of rebuilding my floor jack. I found good info on rebuilding jacks & sourcing parts on the garage jounral web site.

 

[autobon7]

Yes the www.garagejournal.com site is great. Look up a member that goes by hyball as he has been rebuilding jacks for a long time. Can get you parts or point you in the right direction.