Craftsman floor jack rebuild

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May 4, 2008
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Surely enough as I'm nearing the end of my rod bearing replacement, my floor jack decides to start leaking down.

This is the jack, has anyone rebuilt these and/or replaced any seals?

I can crank the handle down as hard as I can but it will slowly drop with weight on the cup.

I don't think its low on oil, but possibly.

All input appreciated.

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Check out the jack repair threads on The Garage Journal. Import jacks seem to be fairly generic, so you can probably rebuild it. Old imports might be worth it (1970s-1980s), but new ones probably aren't unless you are looking for a project. You might need a pin spanner to get the tank nut off, but this one might not require that tool.
 
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That looks exactly like my (leaky) Craftsman jack. I got mine around 2003? I happened across a video that explained how to replace the o-rings, but I could never get the nut off the cylinder. I believe these jacks are examples of how far Craftsman had fallen - just Chinese jacks painted and labeled for Sears. As I recall the jack only had a 90-day warranty.


https://m.youtube.com/watch?v=vIp8GO5PIFA
 
^ How far they've fallen? I consider it reasonable service life to get 16 years out of a *budget* jack before it needs repaired.

I have an older version of that C-Man, back when they made them just as sturdy but were rated for only 2.(something) tons and were light silver with a black handle.

I do recall that once I had my C-Man on its side or upside down or something (I was cleaning it, IIRC) and had to bleed air out and top off the fluid to get it to stay up, and it has worked fine since then.

Definitely try to bleed it and top off the oil before planning a rebuild. It also looks like it could use some cleaning and lubing from the second pic.
 
Hydraulic fluid is not leaking. Maybe it's all leaked out.

First, purge air from the system. Then top off fluid. Now clean off exterior and lubricate all moving parts. If all is well, it will work. If not, you will see the leak. If there's a leak, you will need new seals, gaskets, and o-rings.
 
I agree it's not the cleanest, I had just finished R&R my oil pan to replace rod bearings, and the jack has seen its share of fluids from the vehicle during the whole process.

It will lift all the way up, just won't hold a reasonably heavy load...over maybe 100 lbs. It will very, very slowly leak down, holding up a crossmember under the trans, it leaks down about maybe 1/4" per second.

It has a rubber plug on the cylinder and if I try to pry it up I can hear air either escaping to trying to enter.
 
You can find rebuild kits on the internet. I have a Craftsman 2 ton floor jack purchased in the 1980. Have changed fluid regularly. One thing I have noticed is the jack will puke oil out the fill plug if filled with too much oil. Search for repair kits by entering your jack's model number.
 
Originally Posted by Touring5
That looks exactly like my (leaky) Craftsman jack. I got mine around 2003? I happened across a video that explained how to replace the o-rings, but I could never get the nut off the cylinder. I believe these jacks are examples of how far Craftsman had fallen - just Chinese jacks painted and labeled for Sears. As I recall the jack only had a 90-day warranty.


https://m.youtube.com/watch?v=vIp8GO5PIFA
They were rebranding Japanese jacks as early as the late 1960s IIRC. 1970s for sure.
 
Start with cleaning and lubricating. Get fresh fluid. Be sure to buy hydraulic fluid sold as jack oil. Do not substitute with transmission fluid, motor oil, brake fluid, or anything else you think will work. Drain the jack. Add fresh fluid. Purge air. Then top off the jack. You may not need to rebuild at all. Plenty of videos online showing you how to purge the air and refill the jack.
 
In rebuilt my 3-ton, 1990's, Japan built floor jack over the New Year's holiday. Half the battle is identifying the right parts kit. It will come with extra parts, for similar jacks, which always makes it interesting. For my jack, the main problem was the large seal at the end of the ram had shrunk over time. I replaced everything soft, and the ball bearings. Should be good for another 30 years.

I got my kit from Lazzar's Floor Jack aka HCRCnow.com. If you can't identify the jack from their website and your jack markings, give them a call.

When my jack started bleeding down, everything in my garage ground to a halt. I almost purchased a HF jack, glad I didn't. I spent $60 for a rebuild kit, would have spent $90 for a HF jack, but it wouldn't be the rebuildable plate steel 85 pound beast that this thing is.

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At the heart of almost every piece of hydraulic lift equipment - pallet jack, floor jack, et cetera - there is a simple bottle jack or similar operating system. Fluid in one reservoir, gets pumped into another reservoir, whereby pushing a piston. Almost every one I've seen is the same. Those pieces all have gaskets, seals, and o-rings. These wear items eventually give out, and fluid leaks. Even if you can't find your jack model - and you should be able to since that Craftsman jack is so common that hundreds of thousands were probably sold - you can always take any jack apart, then order the seals, gaskets, and o-rings by diameter size. Parts sellers will have a whatever diameter gasket, if you ask for it. A gasket, seal, or whatever, will work in any and every jack, as long as you are using the correct size.
 
oh I'm sure if you had changed the oil on a regular basis you wouldn't be having these issues.....but don't go and have a flush now....much too risky...
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No real answer to that. Different circumstances vary, and there's no guide. Ask an elevator tech, since it's the same hydraulic principal in action. Ask a forklift shop, since it's the same hydraulic system. Ask any auto shop with a lift, how often they change it out.
 
Originally Posted by philipp10
oh I'm sure if you had changed the oil on a regular basis you wouldn't be having these issues.....but don't go and have a flush now....much too risky...
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Nonsense.

Jack hydraulic fluid never needs changed, unless you're talking about every 20 years.

I have to wonder if you are posting into the wrong topic and thought we were talking about transmissions instead of jacks.
 
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I have a Craftsman 3 ton jack that I've had for probably 15 years. The all black one. It's been good until recently. It doesn't leak externally but it leaks down.
I also just bought the yellow 3 ton Daytona jack from HF and I love it. I was going to put the Craftsman jack on the curb and go buy another HF jack this past weekend with the 25% off coupon they sent me but when I got to the counter with the jack and presented my coupon, I was told it did not apply to jacks. I left without a jack.
SO... Now I have a newfound interest in fixing my Craftsman jack. Anyone done this? Probably just a seal kit. I've rebuilt forklift rams so this probably isn't a big deal.
 
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If you re-read this thread, you'll see I have done it.

Before rebuilding, check fluid level and do the air bleed procedure, especially if the jack was stored on its side. Jack oil is cheap, and if you do rebuild, you will need it anyway.
 
Originally Posted by HangFire
If you re-read this thread, you'll see I have done it.

Before rebuilding, check fluid level and do the air bleed procedure, especially if the jack was stored on its side. Jack oil is cheap, and if you do rebuild, you will need it anyway.



Yep. Fluid is full and no air. Jack's also never been on it's side. I'm just going to fix it. Looks like a kit is under thirty bucks.
 
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