I have been having the blades to stop turning on my BX1800 after mowing for about 30 minutes. It mows fine up until you start approaching that time and start running into heavy grass. You can slow way down and it will still mow some but eventually will stop all together. The drive shaft just stops turning. I have been told the clutch may need rebuilding. Just the other day I noticed that the deck leaks down in a while after you shut the mower down. There is no hydraulic fluid leaking anywhere I can see. Could the mower blade issue be related to whatever is letting the deck hydraulic leak down?