SAE J 1953:2018-05-07

This SAE Recommended Practice shall cover mechanical-brake adjustment limit stroke indicators for actuators with visible exposed pushrods and electrical-brake adjustment limit stroke indicators for all air-brake actuators.

This device shall indicate the foundation brake(s) may require adjustment or service when inspected per vehicle manufacturer's procedures. A measurement shall be made to determine actual stroke measurement for any system not factory calibrated.

Stroke indication accuracy of an air-brake actuator can be assured only when all of its components are supplied by the original brake actuator manufacturer.