Brake Rating Power Requirements—Truck and Bus
The minimum performance values in this SAE Recommended Practice are applicable to vehicles with brake systems having typical service pressure ranges 0 to 16.6 MPa (0 to 2400 psi) hydraulic or 0 to 945 kPa (0 to 135 psi) air only. SAE J880 not only provides for determining maximum brake rating power capability, but also permits verification of any desired or arbitrary level such as the requirement established herein. The determining criteria for deciding brake rating power capability are:
a. Cold brake stopping ability.
b. Fade as a result of brake power absorption.
c. Hot brake stopping ability following brake power absorption.
d. Brake system stability following brake power absorption.
e. Functional and structural integrity of brake system following test.
Rationale: Deletion of obsolete terminology (i.e. horsepower). Revision to the brake system service pressure ranges, both hydraulic and air, to more accurately reflect typical system service pressure ranges and governor cut-in pressure settings in accordance with current industry practices..