96 JD-425 Question?

[leftybob]

What would be causing oil to be present on the carb, where the air filter rest's. I guess it's coming fron the crank case breather. The filter was wet with oil. whats causing this? The tractor has about 2000 hrs. Starts good & runs good.

 

[zlock24]

My 445 had same problem, it ended up being bad valve gaskets

 

[Gittyup]

Can you replace these by removing the valve covers and pressurizing one cylinder at a time with a compressor through the spark plug opening with the crank at T.D.C. Would this let you disassemble the lifter arms to insert new seals (keeping the push rods in place) without having to remove engine and open of the crank case? And if so, how much pressure is enough? Anyone know?

 

[zlock24]

Not sure, my dealer did it along with a full service for $375. They also did some other odds and ends

 

[leftybob]

I'm not sure what you mean by a valve gasket. or do you mean valve guide's. The oil is coming from the crank case breather

 

[beenthere]

Might mean the valve cover gasket.
Or first move might be to remove the valve cover and inspect for sludge that may be plugging the drain-back into the breather chamber. A visual inspection should satisfy that this is or isn't a problem.

 

[Gittyup]

Valve cover seal failures wouldn't lead to oil in breather filter. In that case you'd just have a mess on your engine block. Those seals are a pain to get back in place without gasket adhesive.

A Clogged return might cause a problem. Valve seals are little rubber cups that go on the push rods. Or at least that's what the sold me as valve seals I bought for replacement. Just haven't done yet. I would think that if these failed, you'd simply burn more oil (which I'm starting to see signs of on my tractor). But, I'm no expert.

 

[Yellowfever440]

Well your problem is that the crankcase prolly has too much pressure or too much of a vacuum.so bad valve cover gasket could be a problem. It could also be the breather vent, which I believe the motor has to come out to fix that. It is under a plate on the backside of the motor, if I remember correctly it is a 4 bolt plate. The last time I saw this the engine was just flat wore out and needed rings and rebuilt. A 425 with a 60 inch deck wears the motor out faster that a smaller deck. Small deck 425 usually run about 2500 to 3000 hrs and 60 inch deck 425 usually only run 1750 to maybe 2500 hrs. Just the experience I have had, I am not saying yours it wore out at all. Just a possibility. I have a service manual for that series I will look at it and see what deere offers for troubleshooting that problem.

 

[Gittyup]

Easy enough to change the valve cover gaskets. About $12 each and ten minutes each to change (use gasket dressing/adhesive). Can inspect the return ports while in there.

 

[rgs03833]

One of my MTD had too much OIL, it did the same thing... I Drained it all, replace with good LEVEL / CLEAN OILl... There were no more Oil coming up to the Air Filter or Smokes and Engine runs Smoother now too...

The guy who sold me the MTD didn't change the Oil or Rain got in and when I drain the Oil, it was Dirty / Black / Scummy... My guess was since the Oil was Dirty / Scummy... It Clogged the Piston / Compression Pump harder... And then it SPIT upward toward the Air Filter...

If you haven't Changed the Oil recently. Try that first

good Luck !!!