My 3 ton mvp jack will pump up but wont hold

I would check the release valve is not leaking but screwing it in tighter.

Videos and text based instructions.

https://www.google.com/search?q=MVP+Super+Lift++F-395+WM+add+oil

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https://www.harborfreight.com/15-ton-aluminum-racing-floor-jack-with-rapid-pump-62160.html


https://manuals.harborfreight.com/manuals/62000-62999/62160.pdf



1 5 Ton Aluminum Racing Floor Jack with Rapid Pump

with this little bit of information i suggest you do a web search using your question. " help repairing my MVP F765WM hydraulic jack " and look at the youtube videos to see if anyone there has the same issue as you do and found a fix. because this is a safety thing be extra careful as if it fails after you fix it bad things can happen. if your not a mechanical person then i would go get a new one. it is not worth having this fail if your under what is is holding up. as most people forget they need to use some type of support when working under a machine that is help up with a hydraulic jack. but it's you life.

It's a cheap Chinese made lift, if you don't have the paperwork to it then it's doubtful you'll be able to find who actually made it. If it's pumping up and falling, then it's either low on fluid or you have an internal seal leak. I'd focus on just replacing the the Jack as a unit or just go buy a new lift.

First you need to check and see that it is full of fluid. It could be the release valve is leaking. It is the valve you unscrew to let the jack down. You need to unscrew the whole assembly and inspect it to determine condition, fix as required.

hydraulic jack oil. or like me use regular transmission fluid

a good grade hydraulic oil, a lot of part stores sell it if your in a bind and only if you can use ATF

If it won't stay lifted when you twist the handle as tight as you can, then the lock valve may be leaking, Barbara. Examine the hydraulic cylinder - you may be able to spot a crack or something.

For now, though, just twist the handle clockwise as hard as you can. That valve is steel - it's VERY difficult to damage.

dont know about that model but if its in the tank, pretty much the same for all, if it driveable, get it low on fuel so it wont be so heavy, put a jack under the tank may nee some wood or a couple of layers of cardboard on it so you dont puncture the tank, check the fillup tube to see where to disconnect it at and do so if you can, rais e the tank with the jack just a bit to support it while you loosen the 2 straps that hold the tank up slowly and watch to see if any thing else restricts the lowering. do not smoke when doing this. after tank is on the ground discconect everything from tank to slide out from under car, there should be a l 4-5 in circle lid that ti where the fuel pump is, i always wash the tank off first so i dont get dirt in the tank, if you have a rubber hammet knock the circle lock ring counter clockwise, if no rubber hammer use a hammer and a block of wood,NO SPARKS ALLOWED. be careful and if your not sure you can do it take it to a garage