Hello,
I just read the problem you have and my tractor did exactley the same thing way back in November 2010. I was away for almost 4 months and have not posted a reply to my old post way back. Well here it is....I just brought it to the dealer 2 weks ago and just got it back. My tractor is a 2005 model with about 250hrs on it. The problem is there is a shaft that goes from the hydraulic pump that has splines in it. It goes to another part and slips in. The problem is the shaft does not go far enough in so what happens is the splines wear off and presto all hydrolics stop working. My tractor did drive slow for a bit but then stopped working too. It cost me about 2000.00 to get it fixed. The newer tractors all have longer shafts. The dealer tried to get Masey to pay part of it because it is a problem they are aware of...they paid nothing I was really upset and will be calling them next week. I will get my bill and see if there are part numbers that I can post. This will give you a better idea of what I am talking about. Sorry I am not very knowledgable about the hydralic system.