Overseas Jack Rebuild Help Tutorial.
- Thread starter Hiball
- Start date
I can see them now.. Well, here's the deal it might never fracture all the way thru, then again it might separate next time its under load. Its definitely a odd break.. 
If you can give me some measurements I can check my used box for a replacement. If I have one, you can have it for the price of shipping. Lemme know..
If you can give me some measurements I can check my used box for a replacement. If I have one, you can have it for the price of shipping. Lemme know..I can see them now.. Well, here's the deal it might never fracture all the way thru, then again it might separate next time its under load. Its definitely a odd break..
Thanks Hiball. I really appreciate that. I've only had it about 4 days since bringing it over from my grandfather's house and have already grown to preference it over my Costco Alcan jack. It really is smooth. For sentimental reasons and its really impressive quality, definitely hope it can maintain use for another 30+ years with me.
Looks like the wheel specs are about 1 1/4 inches in width, the diameter of wheel that goes over the wheel shaft looks to be 7/8ths and the overall wheel's diameter looks to be 3 and 7/8ths inches.
roadrunner255
Well-known member
You bet it is! I bought mine new in 1976...
...and it's worked flawlessly for the last 36 years.
These were made in Japan under contract for Sears...
...Green is Good! From the look of the saddle in your picture it's hardly had any use. It is most definitely worth $50. I bet it'll last you the rest of your life, it's worth servicing if needed unlike those cheap Chinese made jacks that are flooding the market. These Green Japanese Sears jacks are high quality.
After restoring a 1942 Walker floor jack I know quality when I feel it!
Thomas from the Restored 1930's Auto Shop
http://www.garagejournal.com/forum/showthread.php?t=51567
Hello,
I also have the Sears "Green" 1.5 ton jack that leaves a small puddle of fluid under the jack. The jack lifts ok but I have to add fluid every now and again. Can I purchase o rings to correct the issue?
Thanks!
My advise.. If the jack is still in good mechanical shape, tear it down and inspect components and if warranted replace All the seals. I believe seal kits can be found for your specific model or if your handy with a caliper you can probably save some cash by piecing it together.
Old Hawaiian
Active member
Can those wheels be ground out and welded?
GoNative_TN
Well-known member
I know this is an old thread...but thanks again hiball!!!! It just helped me out. I know you said it took longer to document than to do an actual repair for you...but when something can still help others after all this time, that was time well spent.
Many Projects
New member
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- Oct 17, 2014
- Messages
- 2
Thanks for the thread, Hiball. Referring to your picture of the valve assembly, http://i904.photobucket.com/albums/ac242/hiball76/DSC00965.jpg
On my Larin (LY-2?)2.5 ton, the threads of the male part (plunger?) with the square end got stripped. Seeing the jack slowly dropping down, I turned the handle tighter only to have it go "past" the fully closed position, and the jack dropped rapidly. I attempted to clean up the threads on the plunger, which appeared to be 9mm x 1.0, but now it does not engage the threads in the female part. Perhaps it was a tapered thread or something. Anyway, Larin says they do not stock parts for this jack. Do you know of any sources where I might find a replacement?
On my Larin (LY-2?)2.5 ton, the threads of the male part (plunger?) with the square end got stripped. Seeing the jack slowly dropping down, I turned the handle tighter only to have it go "past" the fully closed position, and the jack dropped rapidly. I attempted to clean up the threads on the plunger, which appeared to be 9mm x 1.0, but now it does not engage the threads in the female part. Perhaps it was a tapered thread or something. Anyway, Larin says they do not stock parts for this jack. Do you know of any sources where I might find a replacement?
I have some Laying Around, but there was a few variations so I would need some Measurements and Picture at Min. If I have some they will be Used, But you more that welcome to them for the cost of shipping.
Many Projects
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Very kind of you. PM sent. (I think!)
Hi guys! I'm facing this too; I've seen where Hiball has explained the problem.
I think I found a way to deal with this for now, I put a vise grip around the handle so that I can have better control of the release valve. What if I weld a socket into the end of the handle so I can use a breaker bar for opening the valve only?
I would really like to limit the rate of fluid flow through the release valve.
TractorJeff
Well-known member
I have an old 50's garage jack? It was left at my Dads house, after seeing there are 35 pages of "I did it!" I'm thinking maybe I haul it home, read this thread again and give it a go!
Thanks!
Thanks!
Bricksforhands
New member
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- Nov 22, 2014
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- 3
I couldn't break the tank nut free from the body on my Sam's Club Michelin 3000# quick rise floor jack. So I had to heat up the nut w/ my mapp gas torch and then use a 24" l. pipe wrench and hit it w/ a 5lb. sledge to break it free. I was this close to just chunking the whole mess in the scrap pile because I couldn't break that tank nut free.
Bricksforhands
New member
- Joined
- Nov 22, 2014
- Messages
- 3
Here's a link to an on-line source for the ram and tank seals for the Michelin Speedy Lift 7000# floor jack mfd by MVP Industries(China). I'm not 100% positive this is the correct kit but it looks awful close. A call to them would be in order.
http://www.hcrcnow.com/shop/seal-kits/mvp/5216
http://www.hcrcnow.com/shop/seal-kits/mvp/5216
guy48065
Well-known member
My hat is off to Hiball for an epic and truly helpful thread. I read every post through page 9 and then skimmed the rest hoping to see my jack. I have a 2-ton Harbor Freight aluminum "racing" jack--the 2-pump speed lift kind. I could only find a mention many pages back that there isn't much interest in repairing these. ALso found a bit of back n forth about how the 2 pumps operate. Clear as mud ;-)
IS there a thread specific to this newer type or is that all there is?
Mine performed fine for several years then one day would no longer lift a load. I've added oil and purged the air in accordance with the mfr directions I received after discovering who made it. The ram does go to full extension but still will only lift a few hundred pounds, at best.
With the lack of pictures and specific guidance I'm reluctant to dive in. Any tips?
IS there a thread specific to this newer type or is that all there is?
Mine performed fine for several years then one day would no longer lift a load. I've added oil and purged the air in accordance with the mfr directions I received after discovering who made it. The ram does go to full extension but still will only lift a few hundred pounds, at best.
With the lack of pictures and specific guidance I'm reluctant to dive in. Any tips?
I'm not 100% familiar with the model, If you haven't been inside the valve system, there is a good chance that the problem is related to a seal failure, whether it's the power side pump piston (would more than likely see signs of leakage) or the main ram piston seal. My advice.. Simply stay away from the valves for now, and tear into the hydraulic unit and verify seal conditions, being able to only lift a couple hundred pounds is a fairly significant problem. The steps for this are very similar to any floor Jack, you must first remove the hydraulic unit from the frame, Drain the oil and either unscrew the tank nut/remove snap ring collar to gain access to the ram/piston seal. I can further assist with some pictures of unit in question.
guy48065
Well-known member
Something I wanted to ask is how can a jack be tested? In older posts there has been mention of gauges and test stands. I have access to just about any kind of test gear & hydraulic equipment--but I don't see anywhere to plumb a gauge to read the piston pressure. I could dead-head the saddle against a load cell and read the actual lift force but this would be a bit of work.
keitho64
Member
Thank you for writing this up!!
I have the same 1 1/2 ton green sears jack that is in Roadrunner's picture. It will work to about 80% lift height then you pump and pump with no more lift.
Thanks to this thread I am going to dig into the jack and see what I can find.
Even better is I inherited a second 2 1/2 ton jack the leaks down. Now I am armed with the skills to repair it as well!
I have the same 1 1/2 ton green sears jack that is in Roadrunner's picture. It will work to about 80% lift height then you pump and pump with no more lift.
Thanks to this thread I am going to dig into the jack and see what I can find.
Even better is I inherited a second 2 1/2 ton jack the leaks down. Now I am armed with the skills to repair it as well!
Glad I found this thread! I came across a free (non working) HF 2.5ton jack a couple years ago. Figured I'd take it for a project or parts since it was free. I'm gonna dig it out and have a go at getting it working again and use as my backup jack!!
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I pulled my jack apart today. It's a Central Hydraulics (HF I assume) 2 1/4 ton, I have no idea of age.
Looks like the Ucup (if this is correct) has turned to sludge.
I used a screwdriver (gently) to poke and chip away at whats left of it down inside the tube. It's coming out, but may be hard to get it all without letting some gas or deisel sit in it over night or something. Unfortunately, now I have no idea what it looked like before to know what kind goes back in it.
This jack was a freebie, so if I can't get it working it's no real loss, but it'd be nice to get it going.
Hiball, any idea on the Ucup?
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Looks like the Ucup (if this is correct) has turned to sludge.
I used a screwdriver (gently) to poke and chip away at whats left of it down inside the tube. It's coming out, but may be hard to get it all without letting some gas or deisel sit in it over night or something. Unfortunately, now I have no idea what it looked like before to know what kind goes back in it.
This jack was a freebie, so if I can't get it working it's no real loss, but it'd be nice to get it going.
Hiball, any idea on the Ucup?
...
I pulled my jack apart today. It's a Central Hydraulics (HF I assume) 2 1/4 ton, I have no idea of age.
Looks like the Ucup (if this is correct) has turned to sludge.
I used a screwdriver (gently) to poke and chip away at whats left of it down inside the tube. It's coming out, but may be hard to get it all without letting some gas or deisel sit in it over night or something. Unfortunately, now I have no idea what it looked like before to know what kind goes back in it.
This jack was a freebie, so if I can't get it working it's no real loss, but it'd be nice to get it going.
Hiball, any idea on the Ucup?
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Definitely a UCUP, Just Measure the Cylinder Bore to retrieve the OD, Measure the Actual Ram where the Ucup sat to get the ID and then measure the distance between the White Washer to the Inside ridge to get the Overall Height. I would Definitely flush the Valve system to remove any and all remnants of that deteriorated Ucup, Probably wouldn't hurt to address the Pump Orings and Tank rod seal while you have it apart.
OK, so here's what I got.....couldn't get the jaws of the calipers into the bore because it sits back inside the reservoir. So, I measured the OD of the Main Ram and the nylon washer that was on it to get close - should be fairly close, right?
Measurements for Ucup
Main Ram / washer OD = 1.572" (40mm)
Shaft OD = .864" (22mm)
Shaft L = .515" (13mm)
My jack has an outer seal both on the Pump Shaft and on the Tank Nut. I haven't bothered the Tank Nut seal but I did booger up the Pump Shaft seal, so it will for sure need replaced. I haven't removed it yet, but got a good "close" measurements of it with the calipers - removing it may mangle it and not allow good measurements.
Measurements for Pump Shaft Seal
Pump Shaft OD = .707" (18mm)
Seal OD = ~ .946" (24mm)
Seal H = ~ .189" (5mm)
I will measure the Tank Nut seal too in a bit.
Do these measurements match common replacement parts?
...
Measurements for Ucup
Main Ram / washer OD = 1.572" (40mm)
Shaft OD = .864" (22mm)
Shaft L = .515" (13mm)
My jack has an outer seal both on the Pump Shaft and on the Tank Nut. I haven't bothered the Tank Nut seal but I did booger up the Pump Shaft seal, so it will for sure need replaced. I haven't removed it yet, but got a good "close" measurements of it with the calipers - removing it may mangle it and not allow good measurements.
Measurements for Pump Shaft Seal
Pump Shaft OD = .707" (18mm)
Seal OD = ~ .946" (24mm)
Seal H = ~ .189" (5mm)
I will measure the Tank Nut seal too in a bit.
Do these measurements match common replacement parts?
...
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OK, so here's what I got.....couldn't get the jaws of the calipers into the bore because it sits back inside the reservoir. So, I measured the OD of the Main Ram and the nylon washer that was on it to get close - should be fairly close, right?
Measurements for Ucup
Main Ram / washer OD = 1.572"
Shaft OD = .864"
Shaft L = .515"
My jack has an outer seal both on the Pump Shaft and on the Tank Nut. I haven't bothered the Tank Nut seal but I did booger up the Pump Shaft seal, so it will for sure need replaced. I haven't removed it yet, but got a good "close" measurements of it with the calipers - removing it may mangle it and not allow good measurements.
Measurements for Pump Shaft Seal
Pump Shaft OD = .707"
Seal OD = ~ .946"
Seal H = ~ .189"
I will measure the Tank Nut seal too in a bit.
Do these measurements match common replacement parts?
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UCUP is a 40 x 22 x12 obviously Metric, Fairly Common. The Actual part you are calling a "Pump Shaft Seal" is a Wiper on these Jacks, They do make multiple lip configurations of Wipers which do act as seals also though, but your standard Metal clad wiper will suffice. Don't forget the Oring in the Bore of the Pump Cylinder, that is vital piece of the Pie. In regards to the Wiper replacement on the Pump and Tank Nut, swap everything over to MM and you will be find. If you can find a Local shop it will be much easier to find suitable replacements. IF you Need to order parts check with the Online resources I gave earlier, If that doesn't suit, a lot of Members have had good luck buying from "The Oring Store". IF doing Mail Order by the Piece, Make sure you double check your measurements prior to placing the order.
Long time reader but this my first post on this forum. I read all 36 pages and some other threads but didn't come across the same issue that I have.
I have the same Craftsman 2 ton aluminum jack that has been pictured here a few times. Although it has a slow leak from the ram, it isn't at all annoying and the jack works fine except the pump periodically sticks down. It has done this more or less since I got it. I was usually able to jiggle it with the handle and get it to pop back up but a couple of weeks ago, it stayed down. I removed the piston spring and the pump retainer with my impact wrench and then was able to hammer out the piston. The piston and cylinder look great. There are two o-ring grooves in the cylinder and this appears to be where the problem is.
The problem is that the o-rings look like Teflon rings. These could be backers but I dont see any rubber under them. Should there be?
Also, the piston looks llike it has a groove for a wide seal. None of the pistons tat I've seen on this or other threads have one. Since here wasn't one on there can I assume that there shouldn't be?
Last, how do you compress the spring when putting this back together? I thought about using a cylinder head valve spring compressor but can't think about where to attach it. Other ideas?
Thanks for your help. Looks like you have a great comunity here.
I have the same Craftsman 2 ton aluminum jack that has been pictured here a few times. Although it has a slow leak from the ram, it isn't at all annoying and the jack works fine except the pump periodically sticks down. It has done this more or less since I got it. I was usually able to jiggle it with the handle and get it to pop back up but a couple of weeks ago, it stayed down. I removed the piston spring and the pump retainer with my impact wrench and then was able to hammer out the piston. The piston and cylinder look great. There are two o-ring grooves in the cylinder and this appears to be where the problem is.
The problem is that the o-rings look like Teflon rings. These could be backers but I dont see any rubber under them. Should there be?
Also, the piston looks llike it has a groove for a wide seal. None of the pistons tat I've seen on this or other threads have one. Since here wasn't one on there can I assume that there shouldn't be?
Last, how do you compress the spring when putting this back together? I thought about using a cylinder head valve spring compressor but can't think about where to attach it. Other ideas?
Thanks for your help. Looks like you have a great comunity here.
Maybe some pictures of the piston/seals and grooves in question? Generally when you have a pump piston that sticks it's because something in the caging is binding up.
A bit of an update. Now that I have daylight, I was able to see the O-rings below backers. The rings were stiff but not hard. I replaced them both and while better, it still slides stiffly. How smoothly and easily should the piston slide in the bore?
Thanks for the reply! Looks like I was typing at the same time. I'll add some pics momentarily.
Its Hard to try to put into words how much resistance should be felt, It definitely shouldn't free fall into the bore and on the other hand you shouldn't need a hammer to move it.
Hiball, I've looked at several places online for the U-cup and there are many variations of styles / materials but I've not been able to find one at all that matches the size 40x22x12 and ran into same issues with the wiper listed....many variations of style / material but no matching sizes.
Do you have any other recommendations of where to find these as they don't seem to be that common where I am looking (blackhawk, oring store, metric seals, etc).
Also, I understand the U-cup should have an oring inside it, but should it also have another plastic washer behind it?
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Did you call the Number in My Signature? If you do ask for Steve Flora and he should be able to assist you, As far as the Ucup Material, Go with Urethane and you will want a Piston style Ucup or they make some Hybrid Ucups today that can be utilized as either a Rod or Piston style but in that size it should be available in Piston. As far the whether it needs to be a Loaded Ucup? Ehh... Not Necessarily, because while they do prevent start up leakage in the Cylinder, They also increase the lip to Wall pressure and sometimes can cause excess Drag issues. Obviously you can remove the Inner part and utilize it strictly as a UCUP if that's all you can find. In Regards to the Washer, Just reuse the one that still on the Ram.
Thanks for the help.
Why I was asking about a washer on the back, I didn't realize it's hard to notice in the pics, but there is a washer visable against the piston, then the 40mm shaft lenght that has a C-clip at the end. I was assuming (yea) that the metal c-clip wasn't likely to just be in contact with the U-cup (I'd think it would lead to early wear?) but maybe had another nylon washer that went between the end of the U-cup and C-clip? But that's just conjecture on my part obviously as this is my first jack tear down.
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Why I was asking about a washer on the back, I didn't realize it's hard to notice in the pics, but there is a washer visable against the piston, then the 40mm shaft lenght that has a C-clip at the end. I was assuming (yea) that the metal c-clip wasn't likely to just be in contact with the U-cup (I'd think it would lead to early wear?) but maybe had another nylon washer that went between the end of the U-cup and C-clip? But that's just conjecture on my part obviously as this is my first jack tear down.
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Gotcha.. Might want to re measure the overall height including that "Metal" Washer to make sure you don't need a 10mm versus a 12mm. The Metal washer's Job is to prevent the Ucup from slipping off the end of the Ram.
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Hi,
I have an MVP Superlift 3 Ton Floor Jack model G-493LWM - purchased in the mid 1990's. I've been browsing this thread for a couple of hours looking for a solution to an issue with the jack, but don't quite understand all the terminology. The jack would pump up, but not hold a load (3/4 ton truck) for very long. I drained the fluid by pulling the plugs and tipping it for a few hours. I installed new jack oil by filling as much as I could and placing a funnel over the fill hole filled with fluid, fully extending the jack by hand (which drew fluid from the funnel), then turning the handle to release the jack. Air and discolored fluid would fill the funnel. I replaced the fluid in the funnel and repeated until the discoloration stopped and very little air appeared when I released the jack. I put the jack under my truck axle, and it now drops about an inch a minute. No obvious leaks are present.
While draining the fluid, I had removed the fill hole cap and a recessed screw with a pointed seat and a cap requiring an allen wrench. When I reassembled, I tightened the recessed screw snugly until it stopped. I've read some mention of an overload screw, but I am unsure to what they are referring.
Under "Jack will lift load, but will not hold", the owners manual Corrective Action is to "Replace Jack"...lol.
Any suggestions would be greatly appreciated. Any links regarding illustrations of jack components would be helpful.
Thanks....
I have an MVP Superlift 3 Ton Floor Jack model G-493LWM - purchased in the mid 1990's. I've been browsing this thread for a couple of hours looking for a solution to an issue with the jack, but don't quite understand all the terminology. The jack would pump up, but not hold a load (3/4 ton truck) for very long. I drained the fluid by pulling the plugs and tipping it for a few hours. I installed new jack oil by filling as much as I could and placing a funnel over the fill hole filled with fluid, fully extending the jack by hand (which drew fluid from the funnel), then turning the handle to release the jack. Air and discolored fluid would fill the funnel. I replaced the fluid in the funnel and repeated until the discoloration stopped and very little air appeared when I released the jack. I put the jack under my truck axle, and it now drops about an inch a minute. No obvious leaks are present.
While draining the fluid, I had removed the fill hole cap and a recessed screw with a pointed seat and a cap requiring an allen wrench. When I reassembled, I tightened the recessed screw snugly until it stopped. I've read some mention of an overload screw, but I am unsure to what they are referring.
Under "Jack will lift load, but will not hold", the owners manual Corrective Action is to "Replace Jack"...lol.
Any suggestions would be greatly appreciated. Any links regarding illustrations of jack components would be helpful.
Thanks....
My advice? Quit wasting money on New Hydraulic oil and tear into then Jack knowing that it's 20 years old and more than likely you have a piston seal that has failed. The overload shouldnt be cranked completely down, it's job is to prevent cylinder pressure from exceeding the seals capabilities, thus it opens when it reaches the jacks rated tonnage.
There are a Handful of companies who sell "kits" for those Green Sears Jacks, lazzar Hydraulics, HPS who's contact info can be found in my Signature and probably a a couple more who can be found by simply googling the Sears model number. Don't be shocked at the price, if memory serves the kits run north of $50, if a person wants to put the leg work in they can probably source the individual soft parts for a little less than half, but it will obviously be less convenient.
I did need a hammer to get it out the first time. Now it's just stiff.
Here are the pics just to confirm that there should not be a seal on the piston:
Also, I needed my impact gun to get it off but am loath to use it to put it back on. Is there a torque spec for the pump assembly to the body?
I did need a hammer to get it out the first time. Now it's just stiff.
Here are the pics just to confirm that there should not be a seal on the piston:
Also, I needed my impact gun to get it off but am loath to use it to put it back on. Is there a torque spec for the pump assembly to the body?
I don't believe anything would be in that Groove, Its not deep enough to really support any Seal. I'm not real familiar with the Newer Craftsman line outside that the majority of it came from Shinn fu. I did quickly glance at the current 2 ton aluminum jack that Omega offers and while its has dual pumps, both pump pistons appear to have the same groove with No indication of Seal or wear ring etc. In regards to the Pump piston being "Stiff", Again its hard to say but if you have to big of Oring in the Groove it can cause excess gland pressure which would translate to the pump piston being difficult to move. The Pump cylinder that screws into the block needs to be tight, Not sure if yours uses a Oring under the end or is strictly Metal to Metal but obviously the Metal to Metal will require more torque to prevent leaks, Just use some common sense.
OK , first post . Have read all 36 pages and decided to do some jack repair . This is for an AC Delco model 34700 , 3.5 ton service jack . It has 2 pumps . Trouble was it would lift to full height but not lift a load . It worked one day and the next it didn't . It is all apart now except for the pumps , didn't want to have too many parts opened up all at once . I am waiting for the seal kit from Delco . This is what I found when I pulled the piston .
The jack was bought new and never opened up , not even for oil . I suspect it is a fragment of the casting . Do you think it is salvageable if cleaned up or is it just trash . Thanks for any help .
The jack was bought new and never opened up , not even for oil . I suspect it is a fragment of the casting . Do you think it is salvageable if cleaned up or is it just trash . Thanks for any help .
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