That dang Hydro gasket!

[squatch]

Looking for pointers or suggestions on that cork gasket between the hydro and diff. I replaced it once with a new factory gasket and it leaked worse than before. So I did it again with some high quality cork/rubber gasket material I had in stock that was aproximately twice as thick. I cleaned everything until spotless with solvent. Inspected all the surfaces. No scratches or cracks. And I used #2 form-a-gasket(one of my favorite sealers for this kind of application) to seal both sides. I also did not punch in the 3 blind holes that factory gasket has. Thought these might make a weak spot. And it still leaks bad when it sits after running. This is a hard spot to inpect. Even with a stalk mirror it's hard to see exactly where it's leaking from in there with out disassembly. I haven't located any non-cork gasket material in the right thickness. I had some but not enough left and can't seem to locate any more locally. I've replaced alot of gaskets over the years. Even have some cutters and gasket punches to make them. But this one is beating me up.

[67hydro]

try neoprene

jason

[Matt G.]

Several things.

One, those aren't blind holes. Depending on the tractor model, the pump drains back into the transaxle via those holes. Some drain through the bearing. Without knowing what model tractor you're working on, I can't tell you if that's your problem or not. Two, "twice as thick" = not good. Use the thickness of material that it was originally designed for. I assume you're torquing the mounting bolts properly after installing the new gasket?

Depending on the model of tractor, the leak might be from something else. A bad input shaft or trunion seal will leak a lot of Hytran fast. If the tractor has internal brakes, a bad o-ring on the puck will dribble, but not leak fast. If it's got an aluminum rear and the front set of mounting bolts worked loose, you could have a cracked transmission housing.

[squatch]

Originally Posted by Matt G.

Several things.

One, those aren't blind holes. Depending on the tractor model, the pump drains back into the transaxle via those holes. Some drain through the bearing. Without knowing what model tractor you're working on, I can't tell you if that's your problem or not. Two, "twice as thick" = not good. Use the thickness of material that it was originally designed for. I assume you're torquing the mounting bolts properly after installing the new gasket?

Depending on the model of tractor, the leak might be from something else. A bad input shaft or trunion seal will leak a lot of Hytran fast. If the tractor has internal brakes, a bad o-ring on the puck will dribble, but not leak fast. If it's got an aluminum rear and the front set of mounting bolts worked loose, you could have a cracked transmission housing.

It's an 1872. Aluminum rear. Those holes are where it was leaking when I started this. One side(outer edge) had mashed out of 2 holes aloowing it to leak. In my case they are blind holes. One side has 3 holes the other nothing but flat machined aluminum. It is leaking from this joint every time I've disassembled it. No sign of leakage elsewhere. I used the extra thick gasket because I had it and the material I used is VERY compressable. Torqued with a torque wrench. and I cleaned the exterior of both cases well before disassembly so I could inspect for cracks ect.