How To Adjust Trailer Brake-In Just A Few Easy Steps

Many people have no idea that they should adjust their brakes at least once or twice a year. However, being able to adjust trailer brakes increases functionality and effectiveness.

Adjusting your brake depends on the frequency of usage and function. After traveling for a long time, primarily through hilly or rocky areas, setting the brake will increase your safety. It will also make it ready for more tasks, thus increasing its efficiency.

However, most people run away from the task because they find it challenging. In this article, you will be learning an easy and straightforward way of how to adjust your trailer brake. It doesn’t require so much expertise. All you need is some determination and a little mechanical idea or vehicle-related skills.

What are the Types of Trailer Brakes?

There are various types of trailer brakes. However, the type of brake system used depends on the weight and the use of the vehicle. The most common types of trailer brakes are:

1. Electric Brake

Electric brakes are brakes that require electricity from the tow vehicle to the trailer battery when braking. It uses electromagnetic current, which is activated when the electric current is equal to the magnetic current produced from the brake. Most trailers use electric brakes, and they come with a controller, which can be adjusted according to the amount of load.

2. Surge brake

The surge brake requires an automatic system that doesn’t need any electrical connection of tow vehicles and the battery. Surge brakes are hydraulic brakes found mainly on a boat and rental trailers. They come very handily, especially when drivers are not conversant with the usage of electrical controllers or do not have the right equipment for using the electric brake system.

3. Air Brake

Air brakes function by producing air through an engine-mounted compressor. The engine tanks maintain a certain amount of pressure. This pressurized air produced when the brake is activated to engage or disengage the trailer when in motion. When the brake pedal is pressed, air pressure is released.

What are the Required Tools for Adjusting a trailer brake?

Here is the list of tools that are required for proper brake adjustment. They are:

  • Jack and jack stand.
  • Screwdriver.
  • A big rock
  • A torchlight.
  • Hand gloves.

How to Adjust Trailer Brakes

There are various ways of adjusting trailer brakes, whether the drum, electronic, and air brakes. You can do it by following these steps.

Step One

Park the vehicle on a suitable floor, especially in a basement that makes it easy for you to work on since you will be working on the inside of the trailer; you will need a steady, firm and level floor to depend on. Also, make sure you wedge your tire on the spot with a sizable rock. Big enough to ensure zero movements of tires. You can use any other materials, but make sure whatever you’re using does not have any negative impact on your tires.

Step Two

Using a jack, jack the tires up. However, ensure to jack the tires appropriately utilizing the manufacturer’s guidelines. After tires are jacked up, secure it with the jack stand.

Step Three

When tires are safe, go to the back of the wheel where the brake plate is placed. There, you will find a little rubber plug. This plug is what you need to remove to see the wheel adjuster near the bottom of the brake backing plate.

Step Four

With your brake adjusting tool, adjust the brake until it matches with the teeth of the star wheel. The is the gear-like wheel with teeth like designs around its margins. If the place is dark, you can use a touch light. Hence, it is not essential. However, the star wheel is located inside the system, so it might be a little difficult to locate.

Step Five

Turn the adjusting tool until the brake locks up. The brake locks up when it becomes impossible to rotate the wheel. During this time, the brake shoes on the drum are now in the center, which is the proper position. After that, try to spin wheels freely.

Step Six

After ensuring that everything is fixed, hook on your trailer to your truck and take a drive around. For your electric brake, use the manual from the controller. Start at about 40 miles per hour and slow down the truck using the controller. Do this for about 20-30 times using just the controller. It will give room for the brake shoe and the magnet to fit appropriately into the drum. After driving for five times, that’s about 200 miles; it is advised to make another adjustment. After that, adjust brakes after every 3,000 miles.

However, some brakes are self-adjusting, especially electronic brakes. But it is required to adjust the new electric brakes first before they are used, the process is called the brake-in process. This is to ensure proper seating of the magnet and brake shoes in the drum.

How to set the gain on trailer brake

The gain is used when adjusting the electric trailer brake. It helps regulate the braking capacity of the electronic brake. If the gain is not set rightly, it could lead to a harmful circumstance because if the gain is too low, there will be less braking power, and too much gain will lead to a system lock-up, which could cause loss of control. However, here is a step by step method of how to rightly set your trailers again.

Step One

Place the gain control in the angle marked by 50% or in the middle of the slider.

Step Two

Check settings by exerting a 20 miles per hour tow of the trailer on a leveled and dry road.

Step Three

Press the manual override button.

Step Four

Check to see the grip of the trailer. If the trailer’s traction is not strong, increase the gain. But if it’s too strong or locked-up, reduce the gain. Continue the routine until you attain the right benefit without locking up the wheels.

How To Adjust Trailer Brake Brakes

How To Adjust Trailer BrakeFAQs

What is a brake controller?

A trailer brake controller is a device used to control the function of the electric trailer brake. It is situated at the cab of the truck and used for monitoring and activating the brake.

It has various functions that help to see information about the braking. Brake controller comes in multiple shapes and features.

Should a new electric trailer brake be adjusted?

A new electric trailer brake should be adjusted immediately. It should be fixed in such a way that the brake pad is almost in contact with the brake drums. Also, it is advised that a new trailer brake be adjusted about 3,000 miles after the first adjustment.

How do you tell if your trailer brakes are working?

It is not very easy to tell whether your brake system is working entirely just by stepping on the brake pedal when test driving. However, for an electric trailer brake system, you can check the side of the brake controller that usually goes from 0-10 or produces a light indicator. If you can’t find this, refer to the manufacturers manual.

This method is more effective and more accurate than that of the trailer brake pedals. After discovering the bar, drive the truck forward but slowly and pull the bar along. If you do this, you will realize that the resistance becomes stronger as you slide from 0 towards 10. But if you don’t feel any resistance or it’s not much, then there’s a problem.

Are trailer brakes self-adjusting?

Trailer brakes can be self-adjusting and manual, depending on the type of brake you install. However, to know if you have a self-adjusting brake, remove the drum from the spindle and look out for an adjustable cable. If it’s found, then you have a self-adjustable brake, but if not found, then you have manual adjustment one.

How do I tell the size of the trailer brake to use?

To know the type of trailer brake to use, you need to know the measurement of the depth and width of the hub of the drum on the axle. That is the diameter of the inner lip and its width.

What are the causes of weak trailer brakes?

A weak trailer brake is caused by worn out brake shoes which may need replacing since they may not be contacting well with the drum. It could also be because of grease on brake surfaces or the drum. If it’s an electric brake, it could be because the brake controller is not working well and should be tested. You could also check the connection between the vehicle and trailer to ensure that they are clean and free of corrosion. Also, check the brake wiring, that’s the one that connects to the magnet and fixes it. If copper windings are piercing out of the magnet, then it needs to be changed.

How do I check if my trailer brake magnet is bad?

One way to know if your trailer magnet is bad is if it has copper windings, even the slightest of it, coming out of it. However, that is not the only note to determine the condition of your magnet. Another way is to use an ohmmeter. But first, you need to ensure that your magnet is warmed up before checking for the resistance. For a 7″ magnet, the resistance should fall under 3.8-4.0ohms while a 10 to 12″ magnet should fall under a 3.2-3.5 ohms resistance.


Having the right knowledge on how to adjust trailer brakes is essential for proper usage, maintenance, and functioning of your automobile. However, knowing the right way and functionality of your car also help to promote its usage and life span.

On formal occasions, you may want to take your truck to a specialist for adjusting. But with these tips, you can adjust your trailer easily by just acquiring some of the relevant tools.


John D. Archer

John D. Archer is a mechanical engineer and writer based on the area of automotive accessories at, A resident expert and professional, John is passionate about all things automotive and loves to share his knowledge. He has good experience in all kind of automotive accessories. He has worked as a chief mechanical engineer in some reputed automotive garage firm.

Click Here to Leave a Comment Below 0 comments

Leave a Reply: