I had a Deere last year the same. Replace the o ring and ended up putting a new cooler on it.

"Replace the o ring and ended up putting a new cooler on it."

Just don't buy a hardware store o'ring they are NOT compatible with oil and will swell and crack, get the OEM o'ring.

Actually, I took the O ring out of my faucet and had to replace that too. . .
I think the thing that happens with these is the composite adapter distorts sometimes.

Well o'rings are made of all sorts of compounds, some are good for water, some resistant to alcohol, some petrolium products. Choose or use the wrong one in any application and it will fail.

Might check http://www.conoverseals.com/aboutus.html for some history and tech info @ http://www.conoverseals.com/Fluid.asp

Depending on the fluid and temp some are just downright bound to fail, most Hardware store o'rings are just meant for use with water and faucets at very low pressures.

YMMV but I would look for the factory recomended o'ring and correct compound rather than risk a expensive repair for a 50 cent hw store quick fix.

The replacement 'O' ring was a Kohler OEM part, not something you would want to substitute. Now I'm curious to see if the cooler base is leaking by eliminating it as Tom suggested.

I removed the cooler and installed a nipple and filter to the filter base, ran it up, leak is sump gasket.

Oh joy! Couldn't be a simpler deal...

This Kohler model (CV-740) actually has an oil pan gasket, I'll change the c/s seal while I'm there.

This is probably one of Kohler's gaskets that comes w/ parts and papers- true to Kohler form. And don't just use any plumbing gasket. (had to nudge the other poster in some good spirited fun ;) Personally, I think they should have stuck w/ RTV...

There was a design flaw in the dowel pin adjacent to the oil pump, the OEM style was an open loop design, which placed pressure on the sump gasket and producing the leak. The replacement gasket from Kohler came furnished with the closed loop design, as seen on any other Kohler. "Do not use RTV" read the instruction, not even that little dollup I always place around that dowel pin. Additionally for tolerance issues if the engine came gasketed, replace the gasket.

Good for another 10,000 miles. Thanks for sharing.

I read some where that the oil runs through one of the alignment guides that have a split in them and the only way to keep it from happening again is to replace the guide with one with a tighter split in it and a new O-ring.Now I have to search and find the guy that's selling them and install with the split towards the inside of the case. Gasket and new dowel part #24 041 54-S. double check this it was taken from another site.