Electric Brakes on your trailer are similar to the drum brakes on your car.
The difference is that your car brakes are actuated by hydraulic pressure, while your electric trailer brakes are actuated by an electromagnet.
The electrical current is fed into the system by the in-car controller and it flows through to the electromagnets in the brakes. Electromagnets are energized and are attached to the rotating surface of the drums which move the actuating levers in the direction the drums are turning.
The resulting force pushes the primary shoe out against the inside surface of the brake drum. The force generated by the primary shoe acting through the adjuster link then moves the secondary shoe out into contact with the brake drum.
Basically increasing the electromagnet current to the magnet causes the magnet to grip the surface of the brake drum more firmly. Therefore applying more braking force to the trailer wheels.
Australian standards call for all trailers over GTM 2tonne to be fitted with adequate electric brakes. Brakes then inturn need to be adjusted from inside the tow vehicle cab via an electric brake controller. No longer can you fit a drawbar controller to satisfy this requirement. Standards suggest that you lose the ability to adjust the braking force whilst you are towing the trailer.
So the key to the safe operation of electric brakes on your commercial trailer or machine trailer, is regular maintenance, cleaning and inspection.
We suggest that you service your electric brakes quarterly or more regularly pending the usage.
You must inspect the and clean the backing plate, magnet arm, magnet and brake shoes.
Any wear spots or scoring to the shoes or magnet, must be replaced to ensure that adequate braking is achievable.
For more information on trailer brakes you can refer to our article on ‘over-ride’ brakes