I recently purchased a 314 with the Kohler K321AQS engine. When I picked up the tractor the battery was dead, it didn't turn over, it didn't do anything. Installed a new battery cleaned up the carb and she fired right up. When I engage the hydro to move forward or reverse the tractor doesn't move it just makes a high pitch squelling sound and nothing happens. I changed the hydraulic filter and fluid and still the same thing. Is there anything else that I can check that may be causing this or is my fear becoming a reality that the hydro transmission is blown?