Towing a Trailer? What You Need to Know About Trailer Brakes

If you’re like us, you want to do all you can to eliminate the possibilities of something going wrong with your trailer while driving. One way to prevent accidents while towing is by using the proper trailer brakes. 

You might be asking: Do I REALLY need trailer brakes? How do they work? Do I need a brake controller? We will discuss all things brake related in this blog post. 

How Do I Know if I Need Trailer Brakes?

Technically, it can never hurt to use trailer brakes. You’ll be decreasing the chances of not being able to stop fast enough in the emergency and causing extra wear and tear on the tow vehicles brakes and tires. There are a few factors surrounding the necessity of trailer brakes. 

Rules on trailer brakes and at what point they are needed vary from state to state as well as vehicle to vehicle. Be sure to look up the state’s law and your vehicles user manual on this matter if you do not currently have trailer brakes. Here is a helpful guide for state to state specifications.

Which Type of Trailer Brake Is Right for You?

There are two main categories of consumer trailer braking systems.

electric brakes

Electric brakes are the most common type of trailer brake. An electromagnet is used to activate the brakes when the driver applies brakes on the towing vehicle. This type of brake gives the trailer more ease when braking compared to surge brakes. Electric trailer brakes require some type of brake controller that have adaptable settings to control the brake force you need.

Inside View Electric Brake

Surge brakes

Surge brakes work by using a hydraulic piston that pressurizes as the tow vehicles starts to decelerate. This pressure actuates the brakes on the trailer wheels reducing the amount of forward force to the tow vehicle. This system is often used on Boat trailers” Here are more details from another article.

How Do I Know if My Trailer Already Has Brakes, and What Type?

If your trailer has a 4-pin connector on the tongue of the trailer and there’s no break controller on the tongue, that means there are neither electric nor surge brakes on the trailer. 4-pin plugs are incompatible with electric brakes. 

The two photos in the section above show the clear difference between surge brakes and electric brakes. It is quite simple to decipher the two because they look very different, and are located on two completely different parts of the trailer.

First, look at the tongue of the trailer to see if your trailer has surge brakes. If you have checked the tongue and there is no surge brake, check the axles of the trailer to see if there are electric brakes. You can check underneath the trailer like shown in the photo above. You can also check from outside the trailer by looking at the rims. In this case, if there are electric brakes, you’ll see a disc behind the rims. The photos below show the difference between trailer axles with electric brakes, and without. 

How to know if your trailer has electric brakes
Trailer without electric brakes

It is possible to have electric brakes on only one of the axles of your trailer. In many cases this is not recommended depending on the weight being towed. If you are wondering whether you need electric brakes on both axles, be sure to check your state laws, as there are states that require both axles to have electric brakes. 

*While it might seem like electric brakes require more from the user with installation and parts, the maintenance is very simple, and in the long run will be the better choice of the two because of how easy it is to operate. 

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What is a Trailer Brake Controller and How Does Work?

A brake controller is a device that helps to control the braking force of a trailer. It does this by sending a signal to the brake actuator, which applies the brakes on the trailer. This enhances safety and control when braking. 

*For in-depth instructions on how to install a trailer brake controller, refer to the owner’s manual of the brake controller. 

Do I Need a Trailer Brake Controller?

So, is a brake controller necessary?

If you are using electric brakes, you will always need a brake controller. Electric brakes will not be active unless a controller is also in use. Brake controllers are the link between your vehicle brakes and the brakes on your trailer. Many states require a brake controller on trailer loads that exceed 3,000 pounds. 

Now, if you are using surge brakes, a brake controller will not be necessary. Surge brakes are self-contained. Surge brakes are built into the trailer when manufactured and for most cases cannot be installed after the trailer is built. They can be modified and converted to electric brakes, but they cannot be reversed and are not the preferred method of brake control. 

There are Two Main Types of Brake Controllers:

Time-delayed Brake Controller

A time-delayed brake controller provides a preset amount of braking power. The power is predetermined by the driver and will depend on the load that is being towed. The brakes are applied on the trailer a few seconds after the brakes on the tow vehicle, hence the name time-delayed.

Time-delayed brake controllers are a less expensive option for lighter towing, but they put more wear on the trailer braking system.

Proportional Brake Controller

A proportional brake controller applies the brakes on the trailer in proportion to how hard you are pressing the brakes in the tow vehicle. This means that the harder you hit the brakes, the more pressure is applied to the brakes on the trailer. This it the recommended type of controller 

Proportional brake controllers are the safer option. With both the tow vehicle and the trailer doing the same amount of work, this type of brake controller reduces the wear on the braking system. 

What Is a 7-Pin Plug?

A 7-pin plug (also known as a 7-pin connector) provides power, light and brake functions for your trailer.  If you are using electric brakes, you will need a seven-pin plug for the proper power and brake electronics to keep yourself and others safe on the road. Surge brakes do not need a 7-pin plug but can be used for power and lights. 

4-Pin Plug VS 7-Pin Plug

Another type of connector used for lights is a 4 plug. There are four functions that are used through a 4-pin connector. The 7-pin connector will have all of the same functions, plus three additional functions to better suit towing needs. 

4-Pin Plug Light Functions: 

  • Right Turn/Brake Lights
  • Left Turn/Brake Lights
  • Ground Wires
  • Tail/Running Lights
4-pin connector

7-Pin Plug Additional Light Functions:

  • Charge line 
  • Reverse lights
  • Trailer brakes
7-Pin Connector

7-pin Plugs and Surge Brakes

Like mentioned before, a 7-pin plug can be used for a trailer with surge brakes, but there are two light functions that will not be used. The two functions that will not be used are for reverse lights and charge. As you can see here in this photo, two of the blades are missing, indicating the inactive functions. 

7-pin plug for surge brake

Testing 7-pin Light Functions:

You can use a circuit tester to know if the functions are working correctly. 

Here are the steps:

  1. Ground the circuit tester to the frame of the tow vehicle.
  2. Sometimes the wiring goes sideways. In order to know which function you are testing, find the top notch and refer to the diagram below.
  3. Touch the tip of the circuit tester to the blade of the function that you want to test.
  4. If the circuit tester light blinks, that indicates that the function is working properly. 

6-Pin Plug

This is another type of pin connector, and the one that you will see least often. The 6-pin plug is not as common because it performs all of the same functions as a 7-pin plug, except for backup/reverse lights. 

Trailer Brakes In a Nutshell:

Trailer brakes are important for a number of reasons. There are two types of trailer brakes – electric and surge. Electric is the most common of the two and is becoming the superior trailer brake because of its ease and control when braking. A brake controller and 7-pin plug will be necessary to use with an electric trailer brake. Keep in mind that the regulations and laws regarding trailer brakes will vary depending on your vehicle and the state you live in. Remember that safety is the first priority when it comes to towing!