Trailer brake controller explained

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 10feet and longer tent trailers and car carriers). Smaller trailers may not contain trailer brakes (for example, basic 4x 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]

Types

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

Air-actuated electric brake controller
  • 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
  • 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;
  • A separate sensor is mounted on the brake pedal to connect to the controller.[6]
    Proportional brake controller
  • 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
  • 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
  • Applies brake current with a ramp-up over time to a certain level set by the driver.[11] [12]

    References

    1. Web site: Trailer Brake Controllers-The Complete Guide.
    2. Book: What You Should Know About Trailer Brakes 1951 Popular Science article that covers the basics very well. July 1951.
    3. Book: What You Should Know About Trailer Brakes, Popular Science, July 1969, pp. 111-113, an update of the 1951 article.. July 1969.
    4. Web site: Hayes Air Actuated brake controller. dead. https://archive.today/20131002201404/http://www.hayesbc.com/?page_id=1065. 2013-10-02.
    5. Web site: Maxbrake controller. dead. https://web.archive.org/web/20091226182121/http://www.plugitright.com/MaxBrakeController.html. 2009-12-26.
    6. Web site: AL-KO Sensabrake controller.
    7. Web site: Tekonsha proportional brake controllers.
    8. Web site: Curt brake controllers.
    9. Web site: Draw-Tite Proportional brake controllers.
    10. Web site: Hydraulic Surge Trailer Brake Actuators . 2014-11-21 .
    11. Web site: Curt brake controllers.
    12. Web site: Hopkins brake controllers.