Trailer brake controller

From Wikipedia, the free encyclopedia

A brake controller is usually an original equipment manufacturer or aftermarket-installed device or module. It is mounted to the tow vehicle's driver's-side dashboard area, and engages a trailer's electrical braking system either time delayed, or in proportion to the tow vehicle's brake engagement when slowing down or coming to a halt. A brake controller is not needed with a trailer surge braking system unless using modern electric over hydraulic devices. The trailer in this case usually has either electric friction brakes or electric-hydraulic trailer brake actuators.

Most basic brake controllers will generally have a plus-minus gain adjustment. The tow vehicle operator sets the gain as high as possible but without the trailer brakes locking up after making a few test stops. The heavier the trailer, the higher the gain adjustment is set and therefore the less chances of wheel lock-up.[1]

A wide range of trailers contain trailer brakes (for example, larger boat trailers, horse trailers, covered utility trailers, enclosed trailers, travel trailers including small 10-foot or 3.0-metre and longer tent trailers and car carriers). Smaller trailers may not contain trailer brakes (for example, basic 4-by-8-foot or 1.2-by-2.4-metre utility trailers). It is recommended that, if the total trailer weight is over a couple thousand kilograms, the trailer have some sort of braking system, and the tow vehicle be equipped with a brake controller.[2][3]


There are a different types of brake controllers that are currently or previously on the market.

Air-actuated electric brake controller[edit]

This controller uses the air pressure of the brake system on a vehicle with pneumatic brakes to provide a current to control the electric brakes of a trailer.[4]

Hydraulic actuated electric controller[edit]

This controller uses the hydraulic pressure of the brake system on a vehicle with hydraulic brakes to provide a current to control the electric brakes of a trailer.[5] Some truck manufacturers offers this as an OEM option, like Ford with its Ford TowCommand.

Pedal-mounted pressure pad proportional controller[edit]

A separate sensor is mounted on the brake pedal to connect to the controller.[6]

Proportional brake controller[edit]

Senses the deceleration of the vehicle through a pendulum or similar device to apply a suitable current for braking of the trailer.[7][8][9]

Surge brake[edit]

When the tow vehicle slows down the trailer pushes against it, an actuator applies force to its master cylinder and the hydraulic pressure is transferred to the brakes[10]

Time-delayed brake controller[edit]

Applies brake current with a ramp-up over time to a certain level set by the driver.[8][9][11]


  1. ^ "Trailer Brake Controllers-The Complete Guide".
  2. ^ What You Should Know About Trailer Brakes 1951 Popular Science article that covers the basics very well. July 1951.
  3. ^ What You Should Know About Trailer Brakes, Popular Science, July 1969, pp. 111-113, an update of the 1951 article. July 1969.
  4. ^ "Hayes Air Actuated brake controller". Archived from the original on 2013-10-02.
  5. ^ "Maxbrake controller". Archived from the original on 2009-12-26.
  6. ^ "AL-KO Sensabrake controller".
  7. ^ "Tekonsha proportional brake controllers".
  8. ^ a b "Curt brake controllers".
  9. ^ a b "Draw-Tite Proportional brake controllers".
  10. ^ "Hydraulic Surge Trailer Brake Actuators". Retrieved 2014-11-21.
  11. ^ "Hopkins brake controllers".