The control valve was apparently a known flaw. When I contacted the dealer, they knew instantly what the problem was (i.e. it had happened to many others) They had the part on hand. As the tractor was virtually brand new, they came and got the machine (35 miles one way) repaired and serviced it in less than twenty four hours and returned tractor to me the next day. The new valve is somewhat different in appearance, and nearly a year later (quick find some wood, knock knock) working just fine.Hello Nick - I know this forum is a little dated now - but I just had this exact problem happen to me. That "plug" blew out. Not under any kind of heavy operation, just pushing a small pile of dirt back into a trench...really nothing at all for a tractor. It was the lower one opposite the connections going to the loader cylinders. What was your resolution?
Hope this helps.