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kohler M18oil leak

1859 Views 6 Replies 2 Participants Last post by  turk
I've got this Kohler M18 with a little over 300 hours on it and I recently discovered oil wetness underneath the engine on the flywheel side. From information I've gathered, some have said the oil breather umbrella valve may be the problem causing high crankcase pressure forcing oil out the front crank seal. They suggested changing the umbrella valve to the reed type. My question is: If I do this, would it possibly stop the seepage of the crank seal. I'm hoping it will, because the engine sets in a 1993 fiberglass Power King tractor and the drive shaft connects to the flywheel side of the engine. I see no way to get to the seal and flywheel removal without unbolting the drive shaft and removing the engine from the machine. Even disconnecting the drive shaft, the engine would need to slid forward several inches to remove the cooling shrouds and a pulley fastened to the flywheel. Should I just go ahead a pull the motor, remove the flywheel and replace both the crank seal and oil breather. Sorry for being so long winded. Any suggestions greatly appreciated.
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I can personally attest to the problem of positive base pressure causing oil seeping at a seal, as the large engines at my job are designed with a vacuum system to avoid this very problem. I have no experience with the breather system upgrade you are asking about, but did you check to see if the stock breather valve was sticking due to oil gunk? A faulty breather valve will cause positive pressure in the base leading to leaks and also cause an oil sludge build up over time due to the exhaust gasses not venting properly...including moisture vapor...which will lead to a very thick gunky build up which can cause things to stick, suck as breather valves. Also as the engine has a few hours on it, it may be experiencing high blow by, which will also add to the contaminants getting past the crankcase breather. I would run some marvel mystery before an oil change and use carburetor cleaner to thoroughly clean the crankcase breather valve before I would go any further.
Just pour in a cup or so of it in the oil and run it with full load. You can put a little in the gas if you wish, but it doesnt take much. Seafoam is another similar product like marvel mystery, but it is less oily. I would take apart the breaker valve and hose it down with carburetor cleaner and then run the marvel oil through the engine for a while at full load...then drain the oil. If the problem continues, then consider changing parts.
Also when changing the oil, you might want to switch to a "high mileage" oil since they contain seal conditioners which will make the seal swell and hopefully stop the leak you are experiencing.
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