This SAE Standard provides test procedures for air and air-over-hydraulic disc or drum brakes used for on-highway commercial vehicles over 4536 kg (10000 pounds) GVWR. This recommended practice includes the pass/fail criteria of Federal Motor Vehicle Safety Standard No. TP-121D-01. This revision was prompted by the Five-Year Review interval and contains editorial changes intended to make the document cleaner and more user friendly.
This SAE Recommended Practice provides a test procedure for trucks to evaluate their compliance with Federal Motor Vehicle Safety Standard (FMVSS) 121; Air Brake Systems. Units of measure are English in lieu of metric to be commensurate with FMVSS 121.