Needing direction for my To-20

Greetings to all, I'm J.R. and a newbie to the tractor world. I bought a TO- 20 for a small farm-ett as my wife calls it however the HF had hydraulic issue's of not holding its setting. I tore it down and replaced sleeve, piston and rings, only to have it still leaking down. After inspection I see the fluid leaking from the sleeve. I assume it is getting by the rings on the pistons. I purched parts through yt and am wondering if I should have had it all checked by machinist for a correct fit.
Any suggestions on next path to take will be welcomed.
I'm going to pull it apart again and am looking for specs on sleeve ID, piston OD and ring numbers. Thanks in advance.

Do you mean while in operation? Or after the tractor is turned off? How fast does it leak down?

When the hydraulics are turned off, the lift on a TO20 will fall. If everything is tight--as your's probably is now--it may take several minutes or longer depending on how much weight is on the lift. A well used one (like my TO30, currently) can fall much quicker.

It's similar while in operation. When the quadrant lever is raised the lift should rise nicely even when well loaded (even on a worn one like mine). When the quadrant lever is down the lift will fall--probably somewhat rapidly. If the lever is in the sweet spot in the middle, the lift will drift down slowly just like when the engine is off.

From my understanding, due to their design for their originally intended uses, you aren't likely to get them to be as tight as modern hydraulic cylinders.

As you may already know, your lift has draft control rather than position control. Meaning where the lever is on the quadrant won't control the height of the lift, but the draft of a tillage implement (plow, etc). This is very nice for plowing, not so nice for mowing.

There are workarounds to give them position control (ask or search the archives) if that is something useful to you.

A TO20 is a great tractor. Welcome to the Ferguson world.

Leak down after the tractor is shut off is not factory but is normal. If it takes more then 1 min. to leak down it's probably not worth bothering with. The
TO-20 does not have position control so if your talking about setting the lift part way up and it drifts, that is normal. There are aftermarket position
controllers you can make and attach.

I suppose the first 'direction' for you is to not fix anything that ain't broke. Get the operator and repair manuals, and ask here before tearing into something.
If you want the lift to act like a Ford one, you can replace one steel ring with an o-ring, that is what stops the drop on the competition- but to leak down at a slow rate was a safety feature at that time- kid proof sort of thing??

The hyd piston under that cover is used in some of the Ford applications. The NAA I believe, has
updated seals that should provide a better fit. Now if you tear it all apart you will also notice
the linkage pivot points are worn. With some carbon rods fitted into the slots you can weld the
holes back to being round as they were some 50 years ago. Carbon rod kit should still be available
on flea bay.

Thanks for all the great info, I decided not to go
back into the guts because of the need for what I
want. It does fall much slower and maintains a
setting much better, with a bushhog. For the acreage
I have to cut, I thought I could "set it and forget
it" to the height I needed, live and learn. With 2
chains and master links I now just move the master
links for the first cut and so on til it bottoms out.
I bought the land last fall and the previous owner
never cut it so I have to make at least 3 cuttings
before I can totally drop it.
May plan is to restore next year and look forward to
the wisdom this forum has to offer, thanks again.