[AT] Deere 4020 oil leak

[John Hall]

You'd think an oil leak would be obvious regarding its source. Well I 
have one that isn't.  I'm trying to trace it down but so far no luck. 
Figured I would toss it out to the list to see if anyone here has ever 
ran across such. The worst part is you need to be familiar with this 
machine, maybe 4010, 3020's etc are built the same way. I'm getting 
hydraulic oil dripping off the bottom of the air filter. The oil appears 
to be getting on the clamp that holds the dust bowl on, running down and 
dripping off the bowl on to the area between the radiator and fuel tank, 
then running and dripping on a front tire (tricycle front end). I 
figured it was a line or something going to the oil cooler which is 
mounted right beside the air filter. Pulled the hood off and everything 
looks dry. Can't find a leak anywhere. Nothing appears to be spraying 
oil either. Its too clean to be engine oil, and does not appear to be 
diesel or anti-freeze. It leaked enough when I parked it last night that 
it ran all the way down the face of the tire. I left it in the shop 
tonight to see what is going on. Anyone ever heard of such a problem?

John Hall