What Is A Trailer Brake?

AP Products 014122259 Electric Trailer Brake Assembly 12" x 2", Left
AP Products 014122259 Electric Trailer Brake Assembly 12" x 2", Left from www.walmart.com

What is a Trailer Brake?


A trailer brake is a crucial component of a towing system that helps to slow down or stop a trailer when the tow vehicle brakes are applied. It is a safety feature that ensures the trailer remains stable and controllable while being towed, especially when hauling heavy loads or traveling downhill.

Types of Trailer Brakes

There are primarily three types of trailer brakes:

1. Electric Trailer Brakes

Electric trailer brakes are the most common type and are typically found on trailers that weigh more than 3,000 pounds. They are powered by an electric controller in the tow vehicle, which sends an electrical signal to activate the brakes on the trailer. This type of brake system provides proportional braking, meaning the force applied to the trailer brakes matches the force applied to the tow vehicle’s brakes.

2. Hydraulic Surge Brakes

Hydraulic surge brakes are commonly used on boat trailers and some smaller utility trailers. They work by sensing the deceleration of the tow vehicle, which activates the trailer brakes through a hydraulic system. Unlike electric brakes, surge brakes do not require an electric controller in the tow vehicle.

3. Electric Over Hydraulic Brakes

Electric over hydraulic brakes combine the benefits of electric and hydraulic systems. They use an electric controller in the tow vehicle to activate a hydraulic pump, which then applies hydraulic pressure to the trailer brakes. This type of braking system is often found on larger trailers or those hauling extremely heavy loads.

How Do Trailer Brakes Work?

Trailer brakes work by converting kinetic energy into heat energy through friction, thereby slowing down or stopping the trailer. When the tow vehicle’s brakes are applied, the trailer brake controller sends an electrical or hydraulic signal to the trailer brakes, causing them to engage. The brake shoes or pads press against the brake drums or rotors, creating friction and generating the necessary stopping force.

The Importance of Trailer Brakes

Trailer brakes are essential for safe towing. They help to prevent trailer sway, reduce stopping distance, and provide better overall control of the towing combination. Without trailer brakes, the tow vehicle would bear the entire braking load, putting excessive strain on its braking system and compromising safety.

Choosing the Right Trailer Brake System

When selecting a trailer brake system, several factors should be considered, including the weight of the trailer, the towing vehicle’s braking capabilities, and local regulations. Consulting with a knowledgeable professional or a trailer brake specialist can help determine the most suitable brake system for a specific towing setup.

Maintenance and Inspection

Regular maintenance and inspection of the trailer brake system are essential to ensure optimal performance and safety. This includes checking brake fluid levels (if applicable), inspecting brake pads, shoes, drums, and rotors for wear, and ensuring proper adjustment of the brakes.


A trailer brake is a crucial safety feature that helps control and stabilize a trailer while being towed. Understanding the different types of trailer brakes, how they work, and the importance of their proper functioning is vital for safe towing. Regular maintenance and inspection are necessary to ensure the trailer brakes are in optimal condition and provide reliable stopping power when needed.