It may be a head gasket, but if so, it isn't a big problem. It is an easy job to pull the head and replace the gasket. Of course check for cracks, but the 3-cylinder Yanmars do not seem as prone to cracking as some of the older 2-cylinder models.
"When i remove the radiator cap after the tractor has cooled down, there is still pressure built up in the radiator."
I could be wrong, but I don't believe that is possible. That has to be vacuum caused by drawing neither water nor air back into the radiator as the coolant cools to normal temterature and contracts. Is it emptying the radiator or only dropping 1"-2"?
It could be vaccum, but if it was vaccum, would it not draw water back in. If I don't refill the radiator, it will almost empty the radiator. The overflow bottle will fill and overflow. The coolant comes out the overflow tube foamy like. I guess I will be taking it back from the dealer I bought it from this weekend, since it is under warranty, but it is a 4 hour trip one way.
Those are classic head gasket symptoms. It will take longer to drive to your dealer then to fix it, yet it is probably the best thing to do in case it is more serious than just a gasket.
Just an update, I solve my problem. I got a replacement radiator from my dealer, and that has solve my problem. I guess the other radiator was partially stop up. My Dealer has been great. If your are in North Alabama, be sure check out Fredricks Equipment. /forums/images/graemlins/laugh.gif
