Works with Dexter 9K-10K electric self-adjust brake assembly Right Hand (Passenger Side) 12-1/4" X 3-3/8". 12-1/4" x 3-3/8" electric brake assembly fits 9,000 to 10,000 lb. axles with 7-bolt flange pattern. Brake magnet has yellow wire. interchangeable part #'s 6400045, 023-450-00.
Electric brakes are similar to the hydraulic drum brakes used on automobiles and trucks. While those brakes are actuated by hydraulic pressure, generated by the master cylinder to expand the wheel cylinder, electric brakes function by the action of an electromagnet inside the brake drum. when voltage is sent by the brake controller to the electromagnets, they are attracted to the rotating armature surface of the drum. The sliding friction of the magnets against the armature surface actuates a lever which in turn expands the brake shoes out against the drum surface, much like the action that occurs within a hydraulic brake when the wheel cylinder expands. The braking effort is modulated by varying the amount of voltage supplied to the magnets whereas, hydraulic brakes are controlled by the output pressure of the master cylinder.