Hello i have a 66 580ck witha 207D in it and the unit been sitting out side all winter and i have noticed the when I checked the oil the oil level had raised so i drained the oil and clean water came out. I check the Rad and it has green prestone in it so its not comming from the cooling system. I have a plastic pipe with a top covering the muffler so no water should be getting in there. Any other ideas where it might be comming in or to check. Thumpalong
Possible condensation Just meet an old timer who has been helping me out a bit. The dude is 78 years old and still working on heavy machines. Amazing. Any how I had some clear water in my oil when I checked for a coolant leaks after hearing engine noise. He said it is quite normal in the old case to get some water in the oil because they don't breath well enough to dry out the condensation caused by normal engine cooling. There is a tube on the exhaust side of the engine that goes up to the check valve in the valve cover. Make sure they are cleaned out so the engine can breath. (as per the old guy - that helps reduce the amount of water in the oil) However it sounds like you might have more than just that as an issue.
Another area you could check is the valve cover gasket(s). Despite adequate oil control, a cover gasket might let water in from melting snow. There are 2 seals on the top of the cover too. Phil