An Investigation of Integrated Retarder/Foundation Brake Systems for Commercial Vehicles

Commercial vehicles such as buses and trucks operating on our highways today have brake systems designed to achieve acceptable levels of braking performance for both effectiveness stops and long downhill braking. Using foundation brakes alone, temperature limitations have resulted in heavy drum and brake assemblies. Basic engineering analysis reveals that hydrodynamic retarders can be designed to absorb nearly downhill braking energy in addition to up to 90% of the braking energy developed during a typical effectiveness stop. Integrated retarder/foundation brake systems allow significantly increased downhill traffic speeds, and decreased driver fatigue due to improved ease of vehicle control, and provide brakes that are essentially fade free during extended downhill operation. Vehicles thus equipped will exhibit three to four times longer brake lining life, lower maintenance costs, and vehicle down times, as well as higher operating speeds. Existing Federal Motor Vehicle Safety Standards need to be modified to include optional procedures for retarder equipped vehicles.