Well today as I began my work day, I was going over (checking oil, cleaning air filter, etc.) my Bob-Cat mower and found that one of the hydro pumps is leaking a pretty good amount of fluid. The fluid has leaked all around the pump and on to the ground. I've never had to have a pump replaced/serviced before. The mower has 1300 hours on it and never had a pump replaced, so it wouldn't shock me if it had to be replaced. Since I'm no expert with the hydro pumps, I don't know if it needs to be replaced or if a gasket just came loose and leaking now. I know a hydro pump will probably cost me $600+/- if that is the problem. So with that description of the problem, what would be the possible diagnosis for the pump?