My floor jack recently crapped out on me when I was fixin the rear brakes. Truck was on jack stands. Needless to say when I got done the rear end was stuck in the air with no way to get down. I did get the truck down after I borrowed a neighbors. My jack was working great when I raised the truck. Two hours later the jack won't go up. It's a Powerbuilt 2 1/2 ton floor jack. I think a seal is blown somewhere. It did not leak at all. Anyone have expeience rebuilding their floor jack. Any information would be appreciated.

 

Having had a jack suddenly fail on me before (dropping a truck on top of me!) my suggestion is to ONLY use a high quality (albeit expensive) jack in the first place or have a professional rebuild your jack.

It is just one of those imporant safety precautions that can not be understated.

 

One of the check valves in your pump probably has a piece of crud in it left over from the manufacturing process. It could be anything from a piece of lint, or paint chip, to a metal shaving. You will need to have a qualified service person clean the pump mechanism and flush the jack.

Gene- What were you doing under a vehicle supported by a jack? That is a major NONO. Were you just reaching under to place a jack stand?

 

Probably same thing happened to him as happened to me....

I jacked the truck up and put it on the stands to do the work. When I went to jack it up to take it off the stands the jack started to work then quit in mid pump. This caused the truck to drop back onto the jack stand (about 1"- 2" drop). Scared the crap out of me!

I've been real suspicious of jacks ever since.

On a side note, I'm real glad I went with the 12 ton jack stands instead of the 6 ton stands (although I think the 6 ton stands would have held up just fine). The 12 ton stands are taller (don't have to extend them as far) and are bigger with a broader base (more stable).

Back to getting the jack repaired/serviced.....

Where does a person take a floor jack to get it serviced/repaired and what would be a ballpark figure on the $$$ involved?

 

To reiterate what Torque1st said: Never, ever go under a vehicle supported solely by a jack. There was an older, family man brought into our ER who was a lifelong pro mechanic that violated this rule. Lying on his back under the car, a frame member caught him right across the forehead and crushed his skull. He will still lucid when brought in but two days later his head was the size and shape of a watermelon. He died. It only takes one time, friends, be careful out there.

 

On the subject of these hydraulic jacks, how are you supposed to change the fluid in these. I have heard that you are supposed to change the oil on occasion.

 

In a jack there are two check valves that are nothing more than a ball bearing with a light spring behind them. The pump rod sucks fluid thru one check ball from the reservoir when it is withdrawn from the pump chamber. When the pomp rod is forced back into the chamber the fluid is forced out past another check ball into the area under the ram. The fluid from under the ram can not flow back into the pump chamber because of the check valve ball. Fluid is released from under the ram by another ball bearing valve held in place by the release screw that you turn to open and close.

When a jack fails under load the fluid under the ram is released thru a ruptured seal ring around the ram. A failure during the pumping process usually means that one or more of the pump check valve ***** have not seated properly. Dirty, contaminated fluid can cause this failure.

When fluid is changed in a jack you must keep everthing absolutely clean. Any grit, lint, paint chips, or metal flakes will cause the jack to fail. If you can't be absolutely clean it is best to leave it alone...

Any hydraulic service shop can service a jack. Some jacks are of course easier to get parts for than others. About the only wear parts in the jack are the seal rings around the ram and the pump plunger. I service my own due to the fact that I have had years of hydraulic experience.

Many people will abuse a jack by tightening the release valve too tight. This causes small slivers of metal to crack away from the ball seat which will ruin the seals and destroy the valves by scratching the ball seats or deforming them under operating pressures. The metal particles can also keep the ***** from sealing like I mentioned above in jack failure.

 

Thanks for the info guys, I'm going to take it to a hydraulic shop.