Have you flushed your brake fluid? This was the big part of the Workhorse brake recall and it isn't just a WH problem. Moisture is drawn to brake fluid and as the moisture builds in the system it will cause corrosion on interior brake parts. Water in the brake fluid will also boil when it gets hot and become a vapor. You will then have the pedal go to the floor and not stop the coach. You can compress a vapor but not a fluid. My first experience with that was on my '89 E350 when it got to 2 years old. I came down a hill and went through a red light. No problem then. I pulled into a Church yard while the brakes cooled off and I changed my underwear. I flush brake fluid every 2 years now.