This SAE Recommended Practice presents requirements for the structural integrity of the brake system of all new trucks, buses, and combinations of vehicles designed for roadway use and falling into the following classifications:
a. Truck and Bus: Over 4500 kg (10 000 lb) GVWR
b. Combination of Vehicles: Towing vehicle over 4500 kg (10 000 lb) GVWR
The requirements are based on data obtained from SAE J294.