Redneck Trailer Supplies

RTS 101: Brake Controls & Actuators

RTS 101 provides basic trailer parts information for the DIYer or for the business owner. For more information, please call Redneck Trailer Supplies toll free at (877) 9 REDNECK (973-3632).

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What is a brake controller?

A brake controller is an OEM or aftermarket installed device or module. It is typically mounted to the tow vehicle’s driver-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 needed if the trailer has either electric friction brakes or an electric/hydraulic trailer brake actuator. A brake controller is not needed with a trailer’s hydraulic surge braking system.

What are the different types of brake controllers?

Although there are several different styles, brake controllers can be divided into two distinct groups: proportional brake controllers and time-delayed brake controllers.

How does a time-delayed brake controller work?

Time-delayed brake controllers provide a pre-determined amount of power to the trailer’s brakes when the tow vehicle stops. The power supplied is pre-set beforehand by the driver and depends on how much weight is being towed.  

A “delay” will always occur when the brakes are pressed. With some time-delay controllers, a sync switch in the control allows the driver to adjust the length of the delay. Time-delayed brake controllers put more wear on both tow vehicle and trailer braking systems, but are less expensive and easier to install than proportional brake controllers.

Are time-delayed brake controllers adjustable?

Yes. Most basic time-delayed controllers will generally have a +/- gain adjustment.  The tow vehicle operator should set the gain as high as possible without the trailer brakes locking up after making a few test stops.  

The heavier the trailer, the higher the gain adjustment will need to be set for acceptable trailer brake performance.

How does a proportional brake controller work?

Proportional brake controllers use a motion-sensing device (accelerometer) to detect how fast the tow vehicle is stopping. The moment the driver applies the brakes, the brake controller applies the same amount of braking power to the trailer’s brakes. 

As a result, if the tow vehicle is stopping quickly, the trailer will also stop quickly. If the tow vehicle stops slowly, the trailer will also stop slowly. 

Proportional brake controllers provide the smoothest braking, and because both the systems are doing the same amount of work, it reduces the wear and tear on the braking system for both the tow vehicle and the trailer being towed.  

Does the number of axles on my trailer make a difference as to what type of brake controller I should use?

Yes. Different brands and styles of controllers are typically designed for use somewhere between 1 and 4 axles. Prior to purchase of your controller, pay specific attention to all of the details of the various controllers so you wind up with the correct style of controller that will provide you maximum braking performance.

What does electric over hydraulic (electric/hydraulic) mean and how does it work as it relates to a brake controller?

An electric over hydraulic system works by using electricity to activate the hydraulic motor in the actuator, which in turn activates the brakes on the trailer. The actuator receives electric signals from the tow vehicle's brake controller and applies pressure to the trailer's hydraulic brakes.

With an electric over hydraulic brake setup, you get the best of both worlds – the great braking control that an electric brake controller provides and the stopping power of hydraulic brakes.

What does air over electric (air/electric) mean and how does it work as it relates to a brake controller?

An air over electric brake control interconnects with air brake systems of the tow vehicle and automatically operates the electric trailer brakes. The controller ties into the air lines that operate your vehicle's brakes so that it can determine exactly when and how hard you apply the brakes in your tow vehicle. 

As a result, the controller activates your trailer's brakes at the same time and with the same intensity as you apply the brakes in your tow vehicle.

Can a controller be mounted anywhere on/under the dash?

No. It is important to inquire as to the specific mounting characteristics of the brake controller before you make your purchase. After your purchase, carefully read and follow the installation instructions.  Many controls are required to be level front to back, side to side, and are required to be facing away from the direction of travel.

Is it best to hard wire (cut vehicle wiring) when installing a brake controller?

No. It is highly recommended that a wiring harness also be purchased to take advantage of the “plug and play” option that is available with many controllers. By purchasing the harness, installation should be quick and easy and there will be less susceptibility to future wiring problems.

What brand of controllers do the Redline/Trailer Parts Pro harnesses fit?

Tekonsha controllers

If I prefer to hard wire the controller, is there a special kit available?

Yes, part #TA05-020 contains everything needed to hard wire the controller.

Where do I find the specific wiring harness for my vehicle?

Please refer to the Brake Controller Harness “Make & Model Fit Chart” in the Redneck catalog.

When installing a controller where does the harness plug into under the dash?

Please refer to the Brake Controllers & Actuators section of the catalog. Use both the “Make & Model Fit Chart” to find the location code and then the “Wiring Harness Application Guide” to locate the actual position of the plug in the cab.

What is a trailer breakaway system?

Need answer

How does my breakaway kit interact with the electric brakes on my trailer?

A breakaway kit is directly wired into the trailer’s electric brake system. In the event of a disconnect situation, the breakaway switch automatically applies the trailer brakes.

Is a breakaway system needed on a trailer equipped with electric over hydraulic brakes?

Yes. The breakaway functions the same as if the trailer was equipped with electric brakes.

Are there laws requiring a breakaway be installed on the trailer?

Yes. Most states legally require trailers with brakes, whether installed from the factory or added by the owner, to be equipped with a breakaway feature in good working order (not required on trailers without brakes).

Where can I find out if the state(s) I will be towing in require a breakaway system?

You can find a listing of towing laws by state here. If you need more information, contact the Department of Transportation for your specific state.

What are the Federal Motor Carrier Safety Requirements for breakaway kits?

DOT regulation 393.43(d) states: “Every trailer required to be equipped with brakes shall have brakes which apply automatically and immediately upon breakaway from the towing vehicle. With the exception of trailers having three or more axles, all brakes with which the trailer is required to be equipped must be applied upon breakaway from the towing vehicle. The brakes must remain in the applied position for at least 15 minutes.”

What are the primary components of an electric trailer breakaway system?

A breakaway system for electric brakes consists of a breakaway switch, pin and cable, battery charger (optional), a 12-volt 5 amp battery, and a battery box.

What is the primary function of the battery?

The battery provides power to the brakes when a signal is sent from the switch, indicating a trailer disconnect has occurred.

What is the primary function of the switch?

The switch is installed at the front of the trailer and engages the brakes with the power from the onboard battery when the switch’s pull-pin is removed.

What is the primary function of the switch pin and cable?

When preparing for towing, the cable is connected to the tow vehicle. In the event of a trailer disconnect, the pin is removed from the switch and the brakes are engaged using the power from the breakaway battery.

Does my breakaway system require a charger?

No. A charger is not required, but without it, the battery will not be recharged and over time will lose power. 

Two types of chargers are available: a maintenance charger, which will not fully recharge the battery, and a quick charger, which will fully recharge the battery in roughly 5 hours.

What is the primary function/purpose of a trailer brake actuator?

Actuators are the method by which hydraulics brakes are actuated, or applied.

What is meant by the term electric/hydraulic?

It is the description used when an electric motor is used to activate a hydraulic pump that in turn actuates hydraulic brakes.

Will one model of Hydrastar actuator work on all brakes?

No. While all Hydrastar actuators have the same physical appearance and dimensions, there are three different models based on the PSI rating: HBA-10, HBA-12, and HBA-16.

What is the primary difference in the three models of Hydrastar actuators?

HBA-10 is rated at 1,000 PSI and is used for all drum brakes. The HBA-12 is rated at 1,200 PSI and can be used for 8K and larger drum brakes or disc brakes with a lower PSI rating. The HBA-16 is rated at 1,600 PSI and is used for all disc brake applications.

How many axles can be used with the various Hydrastar brake actuators?

Up to a maximum of three axles with brakes.

Where should the Hydrastar actuator be mounted on a trailer?

The actuator should always be mounted in a protected area away from road debris and splashing water. On a boat trailer, it should be mounted in a location that will never be submerged when launching or loading a boat. On longer trailers, it is recommended to locate the unit closer to the axles to reduce brake “lag time” because of the longer brake lines.

Is the Hydrastar unit waterproof?

It depends on the model. While all Hydrastar actuators are watertight, they are not designed to be submerged and should not be pressure-washed under any circumstance. The exception to this is the Hydrastar Marine series of actuators, specially designed for submersion and boat trailer applications.

Are the Hydrastar Marine series of actuators suitable for use in salt-water applications?

Yes. The Hydrastar Marine actuators have a watertight EPDM seal, use stainless steel hardware, and are vented to keep moisture out of the aluminum case. However, the actuators should be mounted in a location that is not submerged in salt water.

Ford, Dodge, and GM state that their factory-installed controllers are designed to be used only with trailers equipped with electric brakes. Will a Hydrastar actuator work properly with GM and Dodge factory-installed controllers, as well as the Ford Tow Command factory integrated brake controller?

Yes, in some situations, with the addition of the HBA-CAM2 Controller Adapter. Newer production models of Hydrastar actuators, when used in conjunction with the HBA-CAM2, will function with both the GM and Ford controllers. 

Dodge trucks normally will not require the HBA-CAM2; however, model years 2010-2013 may need an aftermarket brake controller to function properly. See Hydrastar’s Electronic Brake Controller Compatibility Chart for brake controller compatibility and when the HBA-CAM2 is required.

If there is any doubt, Cargo Towing Solutions, the manufacturer of Hydrastar, recommends that aftermarket brake controllers be used instead of the factory controllers for trailers equipped with electric/hydraulic brakes.

Where is the Hydrastar Electronic Brake Controller Compatibility Chart located?

Refer to the Cargo Towing Solutions website (

What is the warranty on Hydrastar actuators?

When properly installed, Hydrastar actuators are warranted to be free from defects in material and workmanship for two years.

Are rebuild kits available for the Hydrastar actuators?

No. Because of the special tools required for assembly and the specifications that must be met for the units to work properly, aftermarket repair/rebuild kits are not available. The only parts that are available are brake fittings and the replacement filler cap (part #HBA-BC).

Can trailers with electric brakes be converted to hydraulic brakes?

Yes. When converting to hydraulic drum brakes it may be as simple as replacing the brake assemblies, running hydraulic lines, and adding an electric/hydraulic actuator. 

If converting to hydraulic disc brakes, the process is more involved and includes installing calipers and rotors, running hydraulic brake lines, and adding an electric/hydraulic actuator.

Why would a customer want to convert electric brakes over to electric/hydraulic?

Electric/hydraulic brake systems provide the best of both worlds – proportional braking of electric brakes along with the better stopping power of hydraulic brakes.