Michelin 3.5 ton floor jack help

[dwf2008]

Hello, is this thread still active? I have the same Michelin 3 1/2 ton jack. It is about 10 years old but hasonly been used about six times. Worked fine a couple of years ago. Now the quick lift works well but when the lift plate reaches the vehicle it will not go any further. My question is there anything I should do before buying a kit and tearing it apart? Thereare no leaks and it stilllooks like new. Does a repair kit have full instructions on how to put itback together?
Thanks

 

[Boudin]

I rebuilt a 10 year old Michelin 3.5 T this past winter. There was a puddle on the floor under the jack from a leaking seal.

I drained the oil, which was super gross (and should probably be changed every year or two). I took the jack apart without issue, however the nut on the cylinder needed a huge socket from a 3/4 drive set I had, plus a 4 or 5 foot cheater bar. Special care should be taken when removing the guts from the valve ports. Work on one port at a time. Start by carefully tightening the adjusting screws and counting the turns to seat the valve. Back off and remove adjusting screw. Than use a magnet and remove one part at a time from the port. I lined them up on a piece of paper and marked down the turns to close and any relevant dimensions. The check balls were taped to the paper.

I pulled out the owners manual and phoned customer service. A gentleman answered after 3 rings. They do not offer any kit, and had very little advise, but gave me contact info for a couple authorized service centers. I phoned the closest one, and after a few back and forths, ordered a kit. It took almost a month to arrive, but better late than never. The kit came with O rings, U cup, and nylon washers. It did not contain any springs or small steel balls. It had several extra O rings and nylon washers and lacked one crucial O ring which I sourced separately from a local hydraulic supply depot. As they say, installation was the opposite of removal, the leak is gone, the jack lifts fine but I still need to set up the quick lift function.

I have included some photo's. The dimensions for the O rings should not be considered exact, they are my best guesses with the calipers I had.



First photo is the kit, left column is surplus bits, middle column were needed bits, and 3rd column are the bits I purchased separately.

Second photo are the guts from the three ports

Third photo are the release and pump plungers, valve ports and cylinder.

Fourth photo is the cylinder housing, ram, U cup and various bits.

On the quick lift port, the piece that goes along with the spring, does it sit on top or bottom of the spring and which way does the pointed end face? Mine blew out when I was trying to bleed it and not 100% sure how that piece works. I currently have it on the bottom of the spring with the pointed end fa ING up in the spring. Jack works but quick lift does not. I'm thinking maybe it should point down towards the ball bearing?

Sent from my SM-G965U using Tapatalk

 

[Hiball]

On the quick lift port, the piece that goes along with the spring, does it sit on top or bottom of the spring and which way does the pointed end face? Mine blew out when I was trying to bleed it and not 100% sure how that piece works. I currently have it on the bottom of the spring with the pointed end fa ING up in the spring. Jack works but quick lift does not. I'm thinking maybe it should point down towards the ball bearing?

Sent from my SM-G965U using Tapatalk

Definitely point “up”, The spring sits around the point and the flat side should show where it rides against the Ball. When I first read your question I was thinking about the Needle valve type of quick lift, versus the ball/seat you have. The stem aids in keeping the spring centered when installed, if it’s not working try tightening down the adjustment a bit to create enough pressure to overcome the lift arm/spring on the quick lift side. If you over tighten it, you will obliterate the quick lift seal. Of course this is assuming your quick lift seals are in good shape and it was working previously.

 

[Boudin]

Definitely point “up”, The spring sits around the point and the flat side should show where it rides against the Ball. When I first read your question I was thinking about the Needle valve type of quick lift, versus the ball/seat you have. The stem aids in keeping the spring centered when installed, if it’s not working try tightening down the adjustment a bit to create enough pressure to overcome the lift arm/spring on the quick lift side. If you over tighten it, you will obliterate the quick lift seal. Of course this is assuming your quick lift seals are in good shape and it was working previously.

Thanks, it has been sitting up for a few years and I don't recall if it was working or not. So that is the way I have it oriented currently. I need to take it back apart, the ball bearings may of blown out when the spring shot out.

Sent from my SM-G965U using Tapatalk

 

[dewsky1961]

I'd like to have a copy of that manual.......

 

[17sierra]

Hi, I have the same jack at home, it just recently developed a problem. It lifts fine about halfway up and then drops fairly quickly. I have checked fluid level and bleed the system multiple times. Aswell as adjusted the valves to the recommended settings from Hiball.
Was wondering if anyone has any insight on the problem, thanks in advance.

 

[trs71]

You have to buy a rebuild kit, as most likelyseals are old and leaking-

I found one at http://jackparts.hydraulicparts.com/parts/2726-t250-03000-000.html

It's quite involved to tear the whole thing apart AND reasseble correctly....

 

[Merrill]

Hi all, so on the G-735, I just got this but haven't been able to get the overload threaded top plug out yet- somebody buggered the head by beating on the area next to the plug. So today I got a nice Harbor Freight vise if I need to test it down, but the guy I got it from says he put in a rebuild kit. Anyway, with the fill hole open and pumping the the plunger I see the reservoir oil level rising with pressure pump and level lowering as plunger is released. The arm doesn't move with lift valve tight or loose. So I'm going to work on the overload screw to get it out and see what the adjustments and components are.
Is there a way to diagnose if the quick lift tube is ruptured; symptoms? Thanks in advance

 

[Merrill]

 

[Merrill]

Is there any way to upload a photo on my hard drive or on my Samsung galaxy

 

[Merrill]

This video is one of the best to rebuild this jack.

 

[paulsomlo]

Is there any way to upload a photo on my hard drive or on my Samsung galaxy

https://www.garagejournal.com/forum/showthread.php?t=162883

 

[Andrewsh]

so I just finished rebuilding mine.
I did not tear it down as far as the others did.
I figured out the 4 bolts holding in the jack, the bar under it and the pin that holds it to the lever, and the pin that holds it to the arm were enough to drop out the jack itself. Plus loosening the pivot arm so it would spread enough for the jack to come out.

I could not get the top of the ******** by hand. I tried a pipe wrench like the guy shows putting it back together in a youtube video.

but it didn't work for me. even took a 5 pound sledge to the pipe wrench.
found a 2 and 1/8 socket and used an impact gun to get it apart.

Like others I found the reservoir seal in the kids don't work. I reused the old ones.

The closing valve uses a ball bearing to seal, and I missed it falling out so didn't know I needed it. the video linked above showed me what I was missing when I couldn't get it to pump up.

I didn't touch any of the don't adjust screws. I only took apart the main body, pulled out the pump and the closing valve.
I replaced all the seals I found there. 3 internal o-rings as I recall.
one of the flat washer seals in the center under the slotted cap was a metal washer instead of the plastic the original was.
The washer that goes inside the pump hole was cut already so it would fit in. Getting the oring in there was a pain.

But 50 bucks later it works again and doesn't bleed down.
took me about 6 hours counting the run out for tools.
lot of the video's skip parts or go way farther to take it apart.

 

[trs71]

You don't live near the Milwaukee area and want to do it again. do ya???

I bought a low pro-big *** jack from HFT- BUT ever since it puked the oil, it's been working fine- I won't trust it, but I'll use it.

 

[pegabby]

Everything looks correct, Assemble the parts as shown making sure all the parts are seated in the spring upon reassembly. I use a dab of bearing grease to hold them together when dropping them in the hole.

Left valve ---> overload tighten the inner screw down all the way and back it off roughly 1 1/2- 2 turns. The outer cover just needs to be tight.

Middle valve, just tighten it down all the way, it is sealed by the oring.

Right valve ----> quick lift adjustment, start out loose and slowly tighten the plug (which compresses the spring against the upper ball) and pump the handle till you get some feedback on the quick lift side. When the system is operating correctly you should get a full lift with 1 stroke (off of load). Be careful not to overtighten this adjustment otherwise it will force pressurized oil into the quick lift tube and rupture the seal and/or tube, versus bypass.

Glad to find this thread, I did blow the seals and cupped the washer, thanks for the direction of repair!

 

[Chuck44]

I to just finished going through the process of rebuilding a Sam's purchased (in 2003) Michelin 3.5T Floor Jack that would not longer lift and was leaking oil. I found this thread and other YouTube videos invaluable in that process. I ordered the repair kit from Century Tool and Equipment and experienced what some of the others did in that some of the O-rings did not fit. I was able to repair the "not lifting" issues with the kit but unfortunately the jack still leaked from the Reservoir. I tried to used the "flat" O-rings that came in the kit for the top and bottom seals on the reservoir, but I could not make them fit in the O-ring grooves. I endued up measuring the original O-rings and from some research determined that they were most likely size-146. I then went to Ace Hardware where I was able to purchase two size-146 O-rings and they did solve the leaking issues. I hope some others find the Reservoir O-ring size information helpful.

 

[The Cobbler]

@Chuck44 post some pictures!

 

[searnhardt]

so I just finished rebuilding mine.
I did not tear it down as far as the others did.
I figured out the 4 bolts holding in the jack, the bar under it and the pin that holds it to the lever, and the pin that holds it to the arm were enough to drop out the jack itself. Plus loosening the pivot arm so it would spread enough for the jack to come out.

I could not get the top of the ******** by hand. I tried a pipe wrench like the guy shows putting it back together in a youtube video.

but it didn't work for me. even took a 5 pound sledge to the pipe wrench.
found a 2 and 1/8 socket and used an impact gun to get it apart.

Like others I found the reservoir seal in the kids don't work. I reused the old ones.

The closing valve uses a ball bearing to seal, and I missed it falling out so didn't know I needed it. the video linked above showed me what I was missing when I couldn't get it to pump up.

I didn't touch any of the don't adjust screws. I only took apart the main body, pulled out the pump and the closing valve.
I replaced all the seals I found there. 3 internal o-rings as I recall.
one of the flat washer seals in the center under the slotted cap was a metal washer instead of the plastic the original was.
The washer that goes inside the pump hole was cut already so it would fit in. Getting the oring in there was a pain.

But 50 bucks later it works again and doesn't bleed down.
took me about 6 hours counting the run out for tools.
lot of the video's skip parts or go way farther to take it apart.

The single ball bearing in the closing valve hole fell out of my jack. Can it literally just be "dropped" back into the hole or do I need to take things apart and "place" it in in a certain way?

 

[Hiball]

The single ball bearing in the closing valve hole fell out of my jack. Can it literally just be "dropped" back into the hole or do I need to take things apart and "place" it in in a certain way?

If the jack uses a ball on the release, Yes it can be dropped in.

 

[searnhardt]

If the jack uses a ball on the release, Yes it can be dropped in.

Thanks a ton! I re-read through the thread and realized that there is a larger ball and, somehow, that one stayed in there. However, the smaller goes on the bottom so I had to take the big one out and put the small one in. I'm at least getting movement now. I'll update once I get everything back together but, again, thanks a ton. This thread worked where YouTube failed me!

Edit / Update: Got the jack back together and it's working as good as new. Special thanks to HiBall and the folks that posted the pictures and details of the set screws, what is under them, and the settings of the screw backoffs.

 

[ajchien]

Try putting the smaller ball in first, and the larger ball on top. I think you probably took out the screw for the “working valve”.