How Electric Brakes Work

Written by Hitchweb Team
Monday, January 7, 2013 — 3 Comments

Take a look at the major parts that make up a brake assembly:

  • Reactor Spring
  • Actuating Arm
  • Shoe Hold-Down Spring
  • Primary Shoe
  • Adjuster
  • Adjuster Spring
  • Magnet
  • Secondary Shoe

Components of an Electric Brake

The large center circle represents the hole through which the trailer spindle goes, so we can install the backing plate on the axle. The 4 smaller holes represent bolt holes which are used to bolt the backing plate onto the Brake Flange which sits behind the spindle.

How does electricity make this brake work? The magnet in the backing plate has 2 conductor wires which tap directly into the trailer wiring. When electricity is on, it magnetizes the brake magnet. The magnet is attracted to the drum face. When it contacts this area, the friction causes it to rotate, which moves the actuating arm, and pushes the shoes out against the drum. Those shoes have a special brake pad material on them that resists the heat caused by that friction. When the shoes press against the inside of the drum, they prevent the hub, and consequently the wheel that's touching the ground from spinning.

How does the electricity get to the trailer brakes? Where does it come from? How do we know which brake to use? Here's how it works: An electrical connection on the trailer plugs into the connector on the vehicle. There are electrical wires running from the trailer connector back to each brake on the axle, as well as to the trailer lights, to create a complete circuit. When the driver steps on the brakes it sends a current to the brake control in the vehicle. The brake control then sends a current back to the trailer to activate the brakes. Here's what that looks like:

How an Electric Brake works

  

Now that you know how an Electric Brake works, go ahead shop for your set of electric brakes or read more about How To Choose An Electric Brake.

Posted in Towing 101

Comments


Mikaela Melbourne
Wednesday, April 9, 2014

Hello Ronald, That is a very common question. Throughout the U.S. and Canada, there are laws in place regarding towing practices depending on the State or Province. Since most RV's and campers travel over several States / Provinces, it is always safest to go with the average-to-stringent laws as a guideline for any given step. Towing laws can change so make sure to check that the trailer passes the requirements on a yearly basis.

Hitchweb Team
Monday, November 25, 2013

Hello Ronald,

That is a very common question. Throughout the U.S. and Canada, there are laws in place regarding towing practices depending on the State or Province. Since most RV's and campers travel over several States and Provinces, it is always safest to go with the average-to-stringent laws as a guideline for any given step. Towing laws can change so make sure to check that the trailer passes the requirements on a yearly basis.

Ronald McDougal
Monday, November 25, 2013

How do I know if my trailer needs to use electric brakes?

Submit a Comment: