Craftsman Floor Jack Rebuild?

[1973Guppie]

I have a 3.5 ton craftsman floor jack that is almost 16 years old. About six months ago, it started not working and I put some more oil in it and it worked alright again. Lately it only will lift a load up to about 1/3 height it used to. I am wondering if this thing is even worth rebuilding? When I pump it up with no load it pumps up nice and high, but with a car under it, it will only lift up so high, which is getting very annoying as I use it frequently. Has anyone rebuilt these and do they reccomend doing so? I am thinking that there is a seal going bad as it just seems to not hold any weight anymore.

thx, Noah

 

[pb4ugo]

Has it leaked any oil?

I had a old floor jack that slowly leaked down and didn't go up all the way too, but never leaked fluid.
I was considering rebuilding it, until I found a web site that mentioned w/these charachteristics
that the valve was probably clogged. The fix as I recall is. W/the jack down close the valve and lift up the arm all the way up. It should stay up most of the way. Put weight on the jack/arm(I just stood on it,240lbs) and release the valve quickly. I did this a couple of times and now it works well. I still leaks down ever so slowly, but way better than it was b4 and goes up to full height. Good Luck!

 

[1973Guppie]

weird thing is that it never has leaked oil before, but I went to fill it up with oil and it took a bunch to fill it up so ? works fine now, just used gear oil, which I know is not right, but the jack is so old whatever, I was out of hydraulic oil, I will use it till it finally craps out on me, 16 years and going.......

 

[Blue77FJ40]

The Otto Service Company, Hydraulic Jacks Home Page has a great site with a lot of info on all types of jacks. Years ago, I bought a rebuild kit from them for a small Walker bottle jack and rebuilt it per their instructions, so far, so good. I don't think that they sell parts anymore, only jacks.

 

[1973Guppie]

I looked for parts on sears website and they are no longer available, it still works but I just bought a harbor freight one for like 60 bucks on sale, we live in a throwaway society now, don't agree with it but it is what it is......

 

[FJ40Jim]

I searched for info on repairing the common Craftsman (China) floor jack, didn't find much in the How-To department.

Mine was leaking fluid when parked, so bad that in a day or two it would only be able to lift a few inches, which is worthless for picking up a Cruiser. I got tired of filling it with oil (and mopping up under it the next day) every time it was needed. Before I went down to Horrible Freight to buy another china junk jack, I decided to dismantle and see what I could see.

The hydraulic ram assembly was easily removed from the bottom of the frame. Then it was clamped upright in the vise. A 54mm hub socket and inpact gun removed the big hexnut from the top of the cylinder. Inside the hex is the o-ring that seals the piston. The o-ring had been improperly installed by the goatherder who built it, so it was twisted in it's groove. The jack has worked fine for several years, but the twisted o-ring finally decided to tear where it was wrinkled in the groove.

A trip to the parts store with seal nut & ram piston in hand turned up a perfect replacement o-ring- 1-5/8 OD x 1/8 section. The scratches and rust spots were polished off the piston, then everything was cleaned & slicked up w/ vaseline. Assembly was reverse of removal, except I did not use the impact, just a long 1/2"ratchet.

The first few uses of the jack had really bad lifting performance, but now it seems to have bled out the air pockets and is working good as new. No leaking out the ram o-ring, and lift performance is strong from top to bottom.