Transmission leak in my 129

three4rd · #1 08-10-2020, 08:48 PM

Had a leak for many years, and then after replacing the cork gasket last year - everything seemed dry. Now, however, past few weeks I'm finding that I need to again keep a container underneath and am seeing some fluid. After mowing today, I took off the tunnel cover and saw a good amount of fluid (and dirt) accumulated in the area near the valve assemblies and also immediately in front of them. I tightened the nut that sort of sits right between (and slightly forward of) the two valves. It wasn't by any means loose, but thought it might be worth it. I cleaned everything up real well underneath and all around the trans - as much as I could - so now will keep an eye on where it seems to be coming from.

Any suggestions? I did see evidence of some fluid near those valves again tonight and I know I wiped it pretty clean when I was done mowing earlier today. I left the cover off so as to be able to examine everything easily. Since I'm seeing fluid up near the top, I suspect it's just running down along the rest of the trans. Will try to narrow it down but any ideas would be appreciated. I've checked it often ever since the cork gasket job last year and have not noticed anything until recently.

TheSaturnV · #2 08-10-2020, 08:54 PM

Wipe the valve tops clean and push your tractor across the floor a few feet once the pressure lets off enough. With automatic valves you should see right away if they're leaking out the top weep holes.

I think manual valves will so something similar, you'll just have to hold the buttons down.

three4rd · #3 08-10-2020, 09:06 PM

I moved it only about a foot (other tractor is in the way right now to go farther) and didn't notice anything. Went back and forth. Tomorrow I'll do more with it. How come it moves so easily? Is it because the cover's off? Usually have to pull up on the lever.

ol'George · #4 08-11-2020, 08:01 AM

Spray the valves off with brake cleaner so they are clean and dry,and
blow off with air hose.
Then take it for a short ride and you will prolly see that they are leaking from the top,
if so, time to send them for rebuild.
If there are buttons on top of the valves, they are old style that came on your tractor, if just vent holes they are automatic and have been updated sometime in the past and the tractor will push easily with that style, no lever needed for actuation.
The old style valves with buttons need them to be pushed down so it can be rolled/pushed around.
The "bolt" you tightened between the valves, is the charge pump relief valve access, and they don't normally leak.

three4rd · #5 08-11-2020, 08:50 AM

I have the buttons at the top. I can easily do as you suggest - a short ride with the tunnel cover off and see what happens.

What about the option of just buying new valves? I know absolutely nothing about rebuilding them nor where I'd even take them to have it done.

One other thing...I assume they just unscrew (right threaded?) I briefly tried to turn them (just to see if loose) and they won't budge either way. I didn't apply much force but have a socket that fits on them.

cooperino · #6 08-11-2020, 09:20 AM

Quote:

Originally Posted by three4rd

I have the buttons at the top. I can easily do as you suggest - a short ride with the tunnel cover off and see what happens.

What about the option of just buying new valves? I know absolutely nothing about rebuilding them nor where I'd even take them to have it done.

One other thing...I assume they just unscrew (right threaded?) I briefly tried to turn them (just to see if loose) and they won't budge either way. I didn't apply much force but have a socket that fits on them.

Yes. they are threaded in. Right hand threads... They can be purchased or rebuilt. Neither solution is cheap. Sometimes used ones can be had from ebay or the sponsors at top of page

three4rd · #7 08-11-2020, 09:52 AM

In checking again this morning, there is some evidence of fluid around the bottom of the trans, and yet on top - at the valve area - everything's dry. Hard to know - could still be what has run down along the sides from areas that aren't readily accessible (to dry off with a rag). I did as much as I could. Will have to drive it and see if any fluid comes out of either valve.

ol'George · #8 08-11-2020, 01:33 PM

If the valves are leaking it is about $37 each to rebuild yours and is not expensive compared to cub at near 4 times that new, and this fellow is well respected on ebay and here, on the forum.
If you buy used you do not have any idea what condition they are in.

http://www.machtechdirect.com/ OR
Here is his ebay listing number:
320670405175
I would strongly suggest you wash the hydro down with say mineral spirits or quick evaporating fluid such as brake cleaner so you know where the leak is coming from.
wiping with rags will give a false positive because of residual oil in cracks/crevices.
Some have good luck dusting the suspected area with baby powder after it is clean and dried of all oil/solvent, then the leak will reveal itself,
otherwise yer just pissing in the wind.

three4rd · #9 08-11-2020, 05:31 PM

Quote:

Originally Posted by ol'George

yer just pissing in the wind.

One of my former bosses - an elementary principal - once told me that....guess it's true LOL

Seriously, thanks for the advice. I've heard about using baby powder already - probably here.

AndrewNoyes · #10 08-13-2020, 07:59 PM

I think someone painted over my tranny vent at one point. After I replaced my cork gasket, was dry for a long time. Once after plowing in the cold, i parked it as usual in the warmer garage. It leaked, that once. Not sure it's your issue, but if pressure can build up it can leak a little.