New Shop

[adsm08 3,995]

Well, I think I found my leak:

 

 

 

These cylinders are super simple. I actually think the HY-2 lift ram is more complex, as it has two chambers.

 

There is a JIB fitting that goes in this hole, which sits at the bottom of the ram, basically against the floor and fluid is pumped in, up the silver shaft, to a chamber at the top.

 

 

This end seals to the inside of the big black tube and the fluid comes out the top, and pushes the black outer tube upward.

 

 

The whole thing sits inside the post, and lays through a pair of holes in the carriages, the bottom of which sits against that ridge near the open end of the tube, and as it is pushed upward by the fluid pressure is pulls the whole thing along.

 

The worst part of this whole thing so far, aside from the mess it made all over my new floor, was figuring out how to release the locking ring that holds the whole thing together. This video is the only one I found that actually showed it somewhat clearly:

 

 

[Handy Don 15,651]

1 hour ago, adsm08 said:

Well, I think I found my leak:

I'd say yes! Hope the parts and repair time aren’t too much.

 

I lent a hand to a friend who was refurbing the lift cylinder for a heavy forklift. Learned that this one was a single action (i.e. pressure fill, gravity drain!) with only a centering guide at the inner end of the rod and a multi-surface gland seal (which was worn and failing) at the outer end of the casing, i.e. no sealed piston. The fluid inlet was on the side of the casing about halfway up. Pressurize the casing and the rod pushes out; relieve the pressure and the lift carriage pushes the rod back in.

[squonk 45,086]

On 12/6/2025 at 10:05 AM, SylvanLakeWH said:

Excellent idea! Maybe add an air hose while you're at it... make clean up a breeze and just imagine the Mrs's reaction!!! 

Air tools for tearing down an engine in the kitchen! 

[adsm08 3,995]

1 hour ago, Handy Don said:

I'd say yes! Hope the parts and repair time aren’t too much.

 

Shouldn't be. Getting the cylinders out was about an hour, should be less to install them once they are back together. At this point it looks like it will be about 5 minutes per unit to swap out seals. I'm not sure what the local distributor will charge, but it looks like parts should be under $100. The real money in lift cylinders is the cylinders themselves, which most shops opt to just change the whole thing out, because the cost of having the lift down an extra day to have them rebuilt is more than the price of an exchange cylinder.

Edited January 3 by adsm08

[adsm08 3,995]

Update:

 

$250 for seal kits and fluid (might still need a little more fluid) and a week (8 days from order to receipt of parts) of twiddling my thumbs, but I think it's fixed:

 

 

This is actually the second trip up, I put it up last night too, so far no leaks found.

[Handy Don 15,651]

If one cylinder leaked, both would descend to the safety stop, right?

 

[adsm08 3,995]

1 hour ago, Handy Don said:

If one cylinder leaked, both would descend to the safety stop, right?

 

 

It depends on exactly what happens and when.

 

On paper each cylinder should be able to lift 4500 lbs, and so should be capable of lifting anything I will ever put on this lift (that Explorer is literally the heaviest thing I own that isn't a building, at about 4300 lbs curb weight), so one cylinder should also be able to hold it up by itself. However a leak in any part of the hydraulic system compromises the whole system since there is only one power head. If it is a slow leak that started while I was working on something but didn't have it on the locks it should do as you said, safely and slowly leak down until it rests on the lock, or the ground if you are below the first lock ( vehicle approx 2 ft off the ground). The leak I had, if it had started while something was already in the air it may have not been so slow, but the locks should still have stopped it.

 

On the other hand I saw a video recently where a guy was in the process of lowering a Mustang when a cylinder failed, so he had the locks released. The car was on the ground before he could react.

 

Let's just say, there is a reason I chose to reseal both cylinders at the same time.

 

Also, when I took the "good" one apart, I inspected the pressure seal carefully before disturbing it at all. These are a mildly pliable plastic material, not a teflon or rubber seal. The pressure seal on the "good" cylinder was intact, no breaks, no chewing wear like on the failed one. As soon as I tried to stick a pick under it to work it out of its groove it shattered.

Edited 4 hours ago by adsm08