Snapon YA642 Rebuild Issues

[asdanzig106]

Hi. this is my 4th rebuild, and the first one to give me trouble. I completely rebuilt it. New washer, heal plate and c-cup. New ball bearings, etc. Everything new. the problem i'm having is, when i loaded it, it sucked in all 7oz of fluid, so i know the pump is good. But when i got to lift it, it goes up a small amount and immediately falls.

its completely loaded with fluid, and bled out. I can manually pull up the cradle, and i can see movement of the fluid in the fill hole when i do that. but it falls immediately. Now, i didn't pull it up manually and then close the handle. i'm wondering if that will us something.

When i adjusted the relief valve, i set it to one full turn open from dead bottom, which is what it was set at when i removed it.

I'm wondering 2 things. I never replace the plastic piece in the U joint/handle. I also rarely rebuild the pumps. But it sucked in all the fluid, and i can see the bubbles being expelled from the fluid container, so i assume the pump is good. if the pump was bad, it wouldn't raise at all, and no air bubbles would come out. I think its somewhere other than the pump.

Anyone have any thoughts?

Thanks.

Alan

 

[swsman]

Honestly, disassemble and see if you missed something. The only way to know for sure.

 

[Hiball]

I would double check the valve components, paying close attention to the Valve order.

Top to Bottom

Big Weight, Big Ball, small weight and small ball.

 

[asdanzig106]

After an hour of trying everything i could think of on the outside of the jack, i had one last brain storm. i thought maybe i didn't put enough fluid in it. so i filled it with as much fluid as i could, and i got it to finally rise. but that was with my fill tank still full of fluid. And once it rose, it slowly drifted down. So i knew the C cut was bad (brand new). So i tore it completely apart and sure enough, the brand new C cup was damaged. I knew when i put it on, the rubber felt very stiff. not like the other ones i had done. there were little cuts in it, and small groove cut in it. So, off to buy more parts and try again. I'm just happy i found it. Such fun.

Alan

 

[Hiball]

I would put eyes on that cylinder bore if your brand new Ucup has damage/grooves.

 

[asdanzig106]

I did hone out the cylinder before i put the new cup in. but i'll take a deeper look. i'm not sure what brand was included in the kit i bought. i just ordered the OEM hein-werner c-cup yesterday. i'm hoping thats a bit softer. I'll keep you posted.

 

[luvtheheat]

I'm afraid to ask how much Snap-On charges for a new floor jack? First-born son?

 

[Hiball]

I did hone out the cylinder before i put the new cup in. but i'll take a deeper look. i'm not sure what brand was included in the kit i bought. i just ordered the OEM hein-werner c-cup yesterday. i'm hoping thats a bit softer. I'll keep you posted.

A couple things, I’m not sure what a C-cup is, secondly that YA-642 was produced during the Lincoln era, regardless Lincoln nor HW is Manufacturing Hydraulic seals. I will add, the Ya-642 depending on series, used two different sized Ucups. I don’t recall off the top of my head what the series cut off was,as I simply kept both in stock.

I can’t help but wonder based off your picture if you tried to install the larger of the two, which is why it is damaged.

 

[asdanzig106]

you are right, its called U-cup. Not sure why i thought it was called a c-cup. I have both sizes. the larger one absolutely won't fit into the bore.

I had bought a kit from Hydraulic Parts Supply in KS for the YA642, and that kit only had the U-cup for the smaller one 227919. I have the series C i believe (older style).

I found another supplier, https://www.hcrcnow.com/

They, sell seals that say the manufacturer is Hein-Werner. Now, whether HW actually makes them or not, who knows.

In the previous rebuilds i had done, the U-cups were not this hard. i sort of knew when i installed this onto the shaft, something didn't feel right. the rubber was very hard, possibly because it may have just been laying around and it was old. who knows.

I ordered 3 of each size from HCRC now, as well as some other stuff. when i get it, i'll see.

I did check out the bore as you recommended, and it looks really smooth, no grooves.

So, i'll put the new seal in next week when i get it and try again.

i'll keep you posted.

thanks.

Alan

 

[asdanzig106]

I'm happy to say, the jack has been successfully repaired and is working as it should. I purchased the seals from Lazzar's HCRCnow company. they sell seals that are actually branded "hein-werner". these seals are far superior to what i purchased previously. This time it went together as it should, and i even pulled the shaft out of the bore to make sure the seal didn't get damaged. then sent it back in for the final "can" and nut install. Thanks for your input. This is my fourth rebuild, and the first one i had issues with. I learned a lot, so it wasn't a bad thing. I wasn't in any rush because i have other jacks to use while i was repairing this one.

It just surprises me how people are just discarding these jack as they fail without any thought about what they are replacing them with.

I'm searching for another long body one. A lot of the newer SUVs require that additional 3" of lift to get the larger jack stands under them. I see another rebuild in my future..........coming soon.

Take care.

Alan

 

[larry_g]

Good to hear that it all worked out.