Small Engines (Lawn Mowers, etc.): Broadmoor 14 Hydrostat loses power, hydrostat, serial type

Question
Our Broadmoor 14 hydrostat mower loses power after a short time operating and cannot go up even the smallest incline.  It seems to get very hot.  To replace the hydrostat drive is very expensive.  Isn't there some way to service the drive (add oil?) to prevent this problem?  Or is it something besides oil leaking that causes this?

Answer
Hello Wilson

I need more information on the Mower just telling me it is  a Broadmoor gets me no where they make a lot of different units with a lot of different rear ends. Send me Mod # Serial # Type or any other numbers that you find on the mower.