Overseas Jack Rebuild Help Tutorial.

[zequ]

Hey Hiball, thank you so much for all this info and for your reply. I ordered this from oringsandmore on ebay :

Hydraulic U Cup Seals Metric Rod Piston 24mm ID x 40mm OD x 8mm

We'll see how that fits.

 

[zequ]

It's fixed. Weighs a ton itself. nice 17 inch lift height.

 

[Ribbon]

Dave,
I'm a new member and just disassembled my old floor jack. I found out that the piston U-cup seal(p/n TKU40x22x12) and the top nut seal(size as measured: 44mm x 22mm x 10mm) were worn out.
Please let me know where I can get the replacements.

Thank you

 

[RonRock]

Well I got through the whole thread. Now it's time for my questions.

I have an old jack (dah) that I need to rebuild. I took it apart and there was no Ucup! Just a lot of tiny pieces of shredded material. So I would like to order a kit and fix it. Trouble is that the jack has lived outside most of it's life and I am unable to read the only tag left on it. I'd guess that someone more familiar with jacks might be able to make sense of the tag. It looks similar to some that I found in the thread, but of course different.




One thing I am unsure of is that there is no grove for a Cclip on the end of the shaft. There is a small "lip" on the bottom that I assume is meant to hold the Ucup. That seems pretty weak to me. I think that I read in the thread that some people suggest putting a grove in the shaft for the Cclip. I have a lathe and that would be easy enough, but thought I'd check before I do that. Maybe not necessary, also might change Ucup dimensions. IDK.



Here is a photo of the MVP cast in the unit, so I'm sure that that will help identify.



I have more photos if needed. I hope the attached photos are not too large, they look like they are from my screen.

 

[Hiball]

That’s plenty of lip to hold a Ucup, I would try and utilize the thickest Ucup available that would fit between the heel and lip.

 

[RonRock]

Thank You Hiball. I was hoping that you might see my post. Any thoughts on what kit I should order?



Here is a very crude drawing of the shaft.

 

[Hiball]

I’m not sure who is putting kits together for this jack, Most people just buy individual components to save some $$$. The MVP line if memory serves was manufactured by Shinn fu.

If I’m reading you measurements right, it looks like it has a 40mm bore x 24mm ID and a thickness of 10mm should do the trick.

 

[RonRock]

Thanks again Hiball. I'll take a bucket of parts to a local hydraulic shop and see what we can find.

On a side note. I have an Oring cone for SAE Orings. I can not find anything other than a caliper to measure Metric Orings. Pretty hard to get an accurate measurement of the diameter of a flexible ring. I wish I could find an affordable way to measure Metric Orings. From what I have found the Japanese standard is the most likely one that I would need.

 

[Shopguy007]

Hey guys. I'm new here with a Michelin G735 jack I just rebuilt. The speedy lift didn't work before the rebuild and still doesn't. Rebuilt it because it was leaking externally (O Ring on Ram was bad) and the U Cup was bad. Replaced all the rest of the Orings while I was there since I bought the O Ring kit for the jack. Back to the Speedy lift. With the adjustment screw all the way out the ram still moves, but not fast. No matter how far the adjustment is screwed in the ram still moves slow. Never changes speed. Took jack back apart and checked Speedy lift, oring, backup washer on the bottom of the tube, speedy lift tube looks ok, and oring and washers in the ram look ok. Put it back together same problem. No matter where the speedy lift adjustment is set the ram moves slowly, all the way out or in. Any advice would be appreciated. Thanks.

 

[Hiball]

If the seals are good, and there No change with adjustment. I Would double check that both balls are in place below the adjustment screw.

It should have a small ball, bigger ball/seat, spring and then the adjusting screw.

 

[Shopguy007]

Thanks Hiball, you are taking about the speedy lift adjustment having 2 balls? If so I'll double
check.

 

[nadogail]

thanks to this thread, i now feel confident that i just might be able to repair a jack.

 

[Hiball]

Thanks Hiball, you are taking about the speedy lift adjustment having 2 balls? If so I'll double
check.

I’m fairly certain it should have two balls/two seats. If your missing the lower ball, there is nothing to redirect the flow of oil upwards to lift the upper ball and feed the quick lift tube. The overload also has a adjustment, but it only uses 1 ball/seat.

 

[Shopguy007]

Makes sense Hiball, I'll ck for the lower ball... Overlaod is set 1 3/4 turns from seat. Thanks for your help!

 

[mark#3]

Could there be air still in the system?Ok I am not a jack mechanic I don't know what the previous comments mean, but I made my comment?

 

[Hiball]

Could there be air still in the system?Ok I am not a jack mechanic I don't know what the previous comments mean, but I made my comment?

Not likely considering the Speed side is a complete dead stick, and Based off the OP’s posts it appears it been a issue previous to the most recent rebuild. Generally Air issues will cause poor performance, Lift/fall short cycles etc. It’s not a bad idea to add a bleeding cycle to any jack that’s been low on oil, rebuilt etc.. but unlikely the cause based off what details I’ve been given.

 

[Shopguy007]

Hiball, I checked the speedy lift adjustment, there is a 5/32 ball, a 15/64 ball, ball seat that goes in spring, spring, and adjustment srew that goes in spring. The bore and seat where the balls go looks clean and smooth. I had taken the jack back apart, the orings, backup washer, speedy lift tube, and orings and backup washer in the ram looked good. They were all new with the kit I just put in. With the speedy lift adjustment just started in the threads the ram still moves and it does with speedy lift adjust screwed in at 4 rds. The overload is set 1 3/4 turns from seat, could that be an problem? Thanks for your help!

 

[Shopguy007]

Forgot the pic.

 

[Hiball]

Components look good, So nothing from the speed side regardless of how far you crank down the adjusting plug? The middle valve is what let’s the jack operate like a normal single speed jack. Try completely compressing the speed side by tightening it down all the way. Don’t put it under load, just operate the jack light.

 

[Shopguy007]

Nothing from the speed side regardless of setting, I haven't seated it completely..
The middle is seated all the way down.
I'll completely seat the speed side and see what happens.

 

[Shopguy007]

Hiball, Seated the speedy adjustment and it works! I was hesitant to seat it initially, read that it would rupture orings or the speedy lift tube. Maybe thats with a load? I backed it off til it didn't work and tightened it about 1/2 round and it works good... That fixed it.

Thanks to this thread you started I rebuilt 2 jacks, a Craftsman 4 ton, and Michelin 3.5 ton which look the same and used the same kits.
I would think the kits we are getting are of better quality than the originals. They should last a long time. Thanks so much for all you help!

 

[Hiball]

Glad everything is working, 1/2 turn down from nothing should be sufficient and prevent damage. If you crank it down to much, the upper ball won’t lift and it will send pressurized oil up tube and then you have problems.

 

[RickP330]

Hi Guys,
Apology up front - this thread is 31 pages long, didn't get to read through it all, but it looks like I am in the right place. Import jack that won't hold pressure, seems like the piston seal might be suspect.

I took it apart as per this thread - but I cannot remove the cylinder from the block. I put a 4' breaker bar on a 2 1/8" 1' drive socket and all of my weight and it won't disassemble. I didn't try it, but is this by any chance a left hand thread? If not I am ready to give up on it and just buy a new one.

I'll stand by to hear from you all before I give up for good. I've made it this far so I might as well wait.
RickP

 

[Hiball]

It will be standard thread, If the hydraulic unit secured in a vise/press a 4’ bar should do the trick.

 

[RickP330]

It will be standard thread, If the hydraulic unit secured in a vise/press a 4’ bar should do the trick.

Hi, a four foot breaker bar and all my weight is all it gets, not willing to hurt myself over this. If that's the final answer, I'll throw it out. and having to buy a new tool isn't all that bad is it?

Do you have a good link to a new jack purchase thread so I don't start a new one? Searching now...
Rick

 

[Hiball]

Hi, a four foot breaker bar and all my weight is all it gets, not willing to hurt myself over this. If that's the final answer, I'll throw it out. and having to buy a new tool isn't all that bad is it?

Do you have a good link to a new jack purchase thread so I don't start a new one? Searching now...
Rick

There definitely isn’t a lack of “Best Hydraulic jack to Buy” threads around here. The Majority are going to scream HF Daytona Super duty, The super duty utilizes Ucups on the Pump pistons and cheaps out on the main ram with a Oring/retainer versus the favorable Ucup and also Carries a 3 year warranty. The cheaper Daytona models use orings on the pump pistons and drop down to a 90 day warranty. If you are in Menards land, you can get essentially the same jack with Ucups all around for about the same price as the HF. I am a big fan of the HW 93642 or 93652 but they are now assemble with global component, are Single speed similar to what you have, but also carry quality seals and a bullet proof pump. The AC hydraulic line generally gets high reviews here at GJ also, IMO Buy your next floor jack based off the following, Company History, Seal components, Local Availability and finally Warranty.

The biggest issue with the Import jacks that are flooding todays markets are poor QC, If you get a good one with quality seals it will give the average joe good service. If you get a dud, you don’t want to be shipping that thing back and forth so a local retailer and warranty do come into play, as most of the time issues take some time to rest there ugly head.

Hope this helps.

 

[RickP330]

Thanks,
I'm tired of buying garbage. I don't want to ever have to go through this again and this is looking really good to me....

https://www.amazon.com/gp/product/B074QSCV5Q/?tag=atomicindus08-20

RP

 

[Hiball]

Thanks,
I'm tired of buying garbage. I don't want to ever have to go through this again and this is looking really good to me....

https://www.amazon.com/gp/product/B074QSCV5Q/?tag=atomicindus08-20

RP

Just know that model only Carry’s a lift capacity of 2900lbs. I know they have higher tonnage models and I’ve seen them much cheaper than $600. It might pay dividends to start a new thread concerning AC jacks as I know there are some other online retailers that carry AC models.

 

[angrysmileyface]

I am having a hard time finding a rebuild kit for my red hf 3ton jack. I want to say I purchased it 15 years ago with a bad lift unit and replaced it then. It no longer even attempts to lift now and is full of oil. And it appears to have lost all of its labels identifying the model and I cannot find the paper work indicating what power unit I purchased back then other it was the same power unit as spe ified in the owners manual.

 

[Hiball]

Who knows? My advice is if you are wanting to bring it back to life, tear it down and seek the individual seals if everything looks good inside.

 

[TimberWolfCanada]

I have a Canadian Tire MotoMaster SpeedyLift jack that doesn't lift a load any more. I replaced the oil, bled the air out of the system. It will cycle up and down without any load but it leaks oil from the left most screw/valve.

I haven't tried replacing any of the seals yet.

Any suggestions are appreciated as I'd hate to just junk it. It was a great jack when it was working.

 

[Hiball]

Obviously that valve cap shouldn’t leak, Did you venture into it? Or did it just start leaking one day? Outside of that, I could speculate, but if you truly want to save it, Tear it down and put eyes on the internals.

 

[TimberWolfCanada]

Previously I removed all the check valves and inspected them, I saw no distortion or corrosion of those components. I also removed the main piston and it looked ok. I didn't replace the U cup. I didn't have one as I couldn't find a rebuild kit for the jack.

Is it likely to be a leaking U cup? I could try to find a replacement at one of the repair shops in town.

 

[Hiball]

Was it working previous to you disassembling it?

 

[TimberWolfCanada]

It wouldn't lift a load before I disassembled it. The SpeedyLift worked and still works. The leaking from the check valve is a new problem. The jack has been sitting in storage for a couple of years and I finally decided to have one more go at trying to save it before I send it off to be melted down.

 

[Hiball]

It wouldn't lift a load before I disassembled it. The SpeedyLift worked and still works. The leaking from the check valve is a new problem. The jack has been sitting in storage for a couple of years and I finally decided to have one more go at trying to save it before I send it off to be melted down.

Well obviously a bad Ucup will prevent the jack from lifting a load, When you say you removed the “Main Piston” are you referencing the Main ram where you could have looked at the Ucup? Or are you talking about the pump piston? I think the leaking valve plug is the Overload, so I’m not sure if the plug just isnt seated or the adjustment below is too light and preventing it from lifting a load. Since it wasn’t working previous to disassembly, I’d say it’s not valve related.

 

[TimberWolfCanada]

Yes, the main ram is what I was referring to.

The leaking valve has a small check ball, larger check ball, ball stem/seat, spring, adjustment screw and a cap screw with an O ring. I can provide a picture if that would be helpful.

 

[Hiball]

Yes, the main ram is what I was referring to.

The leaking valve has a small check ball, larger check ball, ball stem/seat, spring, adjustment screw and a cap screw with an O ring. I can provide a picture if that would be helpful.

Ok, so that is NOT the overload, That is the High side bypass. Did you inspect the Ucup carefully? Sometimes they will split and it’s hard to see, it becomes noticeable once you try and remove it.

 

[TimberWolfCanada]

I'm going to remove the main ram tomorrow and check the Ucup and I'll see if I can get a new one on Monday.

 

[oreo9]

Hi Hiball,

I have one of these older jacks and I am having difficulty lowering my jack. The release gear attached to the handle is not sitting flush inside the gear attached to the jack and is just spinning freely without engaging the other gear. Is there anyway to reposition one of the gears so they are sitting flush inside one another?