WAC 296-307-07007. Requirements that apply to motor vehicle brakes

(1) The employer must ensure that motor vehicles have brakes that will safely hold the maximum load on maximum grades. (2) Trucks parked on an incline must have the steered wheels turned into the curb and must have at least one "driver" wheel chocked on each side, independent of the braking system. Exception: If the truck has a functioning secondary braking system, the turned wheels and chock are not required. (3) The employer must ensure that trailers have working air brakes, or another approved type. Air must be cut into the trailer brake system at the time that the trailer is coupled to the truck. (4) The driver must test truck and trailer brakes before driving down a steep grade.