Hydro Gasket
 

I am having a problem with the cork gasket that fits between the hydro pump and the rear end. The tractor is a 149. I have split the tractor five times trying to stop the Hytran leak.

My latest attempt included the addition of Ultra black gasket sealer applied to the cork. It leaks worse.

Has anyone had this problem? A leaking hydro gasket, despite every effort to fix it?

A few notes:
-It is definitely the gasket leaking. I can see the fluid trail.
-I am using brand new OEM gaskets purchased from Partstree
-I replaced this same gasket on my other 149, and it does not leak at all

I have replaced about 5 of these and NEVER had a problem.

I use or place a small film of gasket sealer on the opposite side of the "sticky backing" and whala......it's fixed.

I would suggest that looking at the "mating surfaces" to see if there is any gouges where the cork gasket mounts.

There are no obvious cracks or gouges on either mating surface. I have cleaned and prepared both mating surfaces with rubbing alcohol. I attach the sticky side of the gasket to the pump, then carefully slide it into place before bolting it back into position.

Like I said before, my other tractor does not leak at all after I replaced the gasket. This one is giving me fits.

I am thinking about putting two gaskets on it, back to back. Has anyone tried this?

I am also thinking about replacing the entire rear end. I don't know...

I know you said your sure it's the cork gasket but take a second look at the trunion shaft seals. Had one leaking on my 2182 and it looked like it was the cork gasket. Make sure every thing is spotless when you put it back together. Some pics of the pump and adapter that the pump bolts up to may show a problem.

Like Sam said, I would also look at the Input Shaft Seal and the Relief Valves. Where ever the leak is, is seems it is dripping down into the cork gasket area.

I actually replaced every seal on the pump last year. I am 100% sure the seals are good.

When the tractor was assembled, I stuffed some paper towel where the pump and the rear end meet. I let it sit. I did not start or run the machine. I checked it after two days, and the paper was soaked with hytran.

I took it apart again yesterday. Did the gasket replacement with ultra black. I decided to let it setup overnight. I checked it this AM. There was a puddle of Hytran on the floor. Upon inspection, the hytran in running from where the gasket meets the rear end.

When you take it apart are the gaskets torn? Do they look like they are compressing as the should? I'm just wondering if maybe Cub has a bad batch of gaskets, maybe they are too thin. It sounds like your doing it the way it should be done.

The gasket was torn this last time because it was stuck with the Ultra Black. Before that, no. The last gasket I removed was in good shape.

Here are some photos of the mating surfaces:

I don't see anything that should be preventing you from getting a good seal. That little nick is not the problem. I'd go get a small chunk of modeling clay, make a small ball about the size of a marble, put it on the tranny housing, then put the pump on and snug up the bolts. Then remove the pump and see what the compressed thickness of the clay is and compare it to the cork gasket. The gasket should be thicker.

Something you could try is Prusian Blue, I think Form A Gasket makes it. If the mating surfaces touch together with out a gasket, put a light coating on one surface and look to see if the surface you didn't coat is coated all around with no gaps. If any part of the surface doesn't have the Blue on it you may have found a problem of the surfaces not being flat.

You are not the only one with the problem. My son Eric and I spent most of today Working on the same problem with a 2072. Close inspection of the tranny and Hydro surfaces does not indicate any problem but we took the hydro out and replaced the cork gasket and after all the work it still leaked. This hydro is not the original so we took it back out and replaced it with the original hydro and used the grey gasket sealer and just a few minutes ago got it back in the tractor. This hydro did not leak before we took it out so we are hopeful that this will fix our problem. We like you are perplexed as to why we are getting the leak.

If you're like me, you refuse to tolerate any leak. I will replace the entire rear end if I have to. If that doesn't work, I will replace the tractor.

I've split this tractor five times over the past two years. Working alone, I am tired and starting to lose my patience with it.

With our 2072 we do not have to split the tractor to get the hydro out but it is a labor intensive job. We did it twice yesterday!!!. We do not tolerate leaks either. If the original hydro that we installed last evening also leaks with a new gasket then we may decide the gaskets are not thick enough. The new gasket on the hydro we took off did appear to be compressed but we are sure that is where the leak is comming from. We can see the hydro fluid seeping down around the gasket and other than the oil seal at the top rear of our hydro there is no other place for oil to leak from. We had a leak from that rear seal and it was spread over the top of the tranny more than down around the cork gasket area and now the top is dry. We hate leaks, possibly forgivable in a dog but not our tractors.

I actually found an old cork gasket without the adhesive that I bought a while back from one of the parts suppliers on this website. I installed it yesterday with Ultra Black on the pump side and bare cork on the rear end side. I have decided to let it sit for a week before re-assembling the tractor. I checked it this AM and again when I got home from work. No leak so far.

From reading this thread I'm almost convinced the MTD sent out a bad batch of gaskets. Think if I have to do another one I'm going to machine the trans adapter housing to take an O-ring along the lines of the newer Cyclops stuff like the 1641's use.

The local Cub Cadet dealer in my area installs 2 gaskets when he removes the pump from the rear end. I haven't tried it yet.....my 149 is leaking and needs the gasket change.

It is possible the gasket is not as thick as it use to be.

We also assembled our original hydro back on the tractor using ultra grey sealant and I filled the tranny today which is a real pain also. the 2072 has the battery in the fender pan but I hooked it up temp and ran the engine to pressurize the system and no leaks and have all systems operating. After an hour no leaks or puddles on the floor. I think we got ours fixed. After I get it back together completely I'll take it out and give it some exercise and we will see. I am wondering about the bearing that sticks out and seems to fit in a recess when assembled and wondered if that might have been our problem It would seem if one hydro bearing stuck out a fraction further one might not be able to get it tight enough. The hydro that leaks also came out of a 2072.

They definitely sent out a bad batch of mule drive belts a few years back. I know because I bought three of them after they kept breaking. That was the mule drive belt for the 149. The belts were the wrong diameter--too thin.

I'm just saying, it does happen. There might be a batch of bad gaskets out there. It can be very frustrating.

Are both you guys (sharky and Paul) sure that it isn't the output shaft seal leaking and dripping/running down? It's directly above it, and if the oil is warm you would never know unless you ran it with the fenders off where you could see the trail. I'd be either changing or checking that seal. I bet that's the leak. There is no way that it is the cork gasket. They can't be "bad". It's a round cork gasket. Only way it can leak is if there is a tear, or if the hydro wasn't close enough to the rear end. Only way the hydro couldn't be close enough is if the housing is made wrong, or the bearing on the rear was sticking out too far. That would present a different set of problems altogether. Change that seal, and try it again. You can get a seal at Napa. I have the number somewhere if you need it.

I cannot speak for Sharkey, but I am convinced that our leak is coming from the cork gasket area. The area above the gasket is dry, and we can see a line of fluid coming down around the gasket that dribbles down to the bottom of the tranny and then hits the floor. When we had a leak at the rear shaft the fluid was blown all over the top of the tranny. The hydro that is in our tractor now has had that seal recently replaced too. Oh well I have not gone to the garage this morning to look for leaks but had none last night.

I have already replaced all of the seals on my hydro pump.

Exactly! You bet that is the very first 4 seals you check, and make triple sure, before you even think about the cork gasket being bad.

I'm in the same boat. Just bought a Cub Cadet cork gasket, and before I could start the tractor, I noticed that pretty colored Hy-Tran leak. I must agree with Sam, on the notion that MTD passed gaskets that were not with in tolerance. Or who ever made them for MTD.

Same here, I don't care for leaks crapping up my tractor,..............

:beatdeadhorse:

I wish you success, and good luck this time around!

Have either of you replaced the bolts? I'm just wondering if you are using longer bolts and they are bottoming out in the tapped holes and not pulling things up tight. What about buying some sheet cork gasket material and cutting your own gasket?

Later Non IH Cadets eliminated the drain hole in the hydro unit, the oil drains back thru the bearing hydro's output bearing. The old IH units with the drain hole has a tiny area to seal...just below the drain hole.

On my next cork gasket replacement job, I'm considering to plug the drain hole in the hydro unit and maybe the rear end. This would increase the area to seal with RTV.

Thoughts?

On our 2072 we suspected the hydro unit was not performing properly and replaced with another identical hydro unit and a new gasket. The replacement hydro leaked around the cork gasket. We ordered two new cork gaskets and used one on the replacement hydro but it still leaked. We then put the original hydro back in and used the remaining cork gasket and finally our leak stopped using a new gasket but stuck it on one side and used ultra grey gasket sealer. That was a lot of work with as many changes we made but no more puddles make me smile.

Hope the repair is going smoothly. As mentioned earlier, I have the exact problem with the new composite cork gasket from Cub Cadet/MTD. Well, after rereading this thread, I know with out doubt, that I installed my gasket with the sticky side on the trans axel, and not the pump.

Something made me ask myself, before I placed it where I did,..... because the mating surface area of the trans axel is rather grooved and not perfectly smooth as that of the mating surface area of the pump. So, why would I want the sticky side on the grooved area of the trans axel? Shucks. I don't see how the sticky side can seal the course area of the trans axel.

For about a week now, I have been pondering at the many reasons why I still had a leak before I turn a wrench again. Though my discovery might not be the answer, but it sure does pay to go back and reread any related material.

Here's what I'm going to try:

1. install "sticky" side to the pump, as suggested.
2. I think I'll use a layer of the Ultra Black silicone between the gasket and trans axel. I did not use any silicone the first time, it was dry installed.

Some folks swear by using neoprene gasket material for a gasket. If the second time is a failure, I will try the neoprene.

John that's what I did the last time, (sticky side to the pump and a little sealer to the rear side) and not a drop of fluid since and we have been using it hard so I'm very happy happy happy lol.

When we replaced our 2072 gasket the last time we cleaned, I mean really cleaned both of the surfaces. We used a single edge razor blade to carefully clean any possible residue from both surfaces. This could have helped with the leaking problem too. We then sneaked the blade back into the wife's leg razor. Do you think she will notice.