Are auto slack adjusters required by law in commercial vehicles?

The use of automatic slack adjusters (ASAs) in commercial vehicles is indeed required by law in many jurisdictions. ASAs are mechanical or automatic devices designed to maintain proper brake shoe-to-drum clearance in air brake systems. They compensate for brake shoe wear by adjusting the pushrod stroke length, ensuring consistent and effective braking performance.
In the United States, the Federal Motor Carrier Safety Administration (FMCSA) mandates the use of ASAs on commercial motor vehicles (CMVs) equipped with air brakes. According to the FMCSA's regulations, 49 CFR § 393.47, all CMVs manufactured after October 20, 1994, must be equipped with self-adjusting brakes or an automatic brake adjustment system.
Additionally, many other countries and regions have similar requirements for ASAs or automatic brake adjustment systems in commercial vehicles. It's essential to consult the specific regulations of the jurisdiction where the vehicle operates to ensure compliance with the law.