How To Adjust Electric Brakes On A Trailer [Easy And Simple Methods]

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Safety is central to towing and driving vehicles. It doesn’t matter whether they’re trucks, cars, watercraft, or railed vehicles. Having your brakes in good condition will guarantee safety. This article will offer a step-by-step guide on how to adjust trailer brakes. Read on.

8 Steps To Adjusting Electric Brakes On Your Trailer

8 Steps To Adjusting Electric Brakes On Your Trailer

Here are a few steps and tools to adjust your trailer brakes for efficiency. As an unpowered vehicle, a trailer needs powering or tow vehicle with efficient brakes.

Step 1: Collect Your Tools

The first step is a no-brainer. You’ll need a few tools to successfully adjust your trailer’s braking system. The tools needed include:

  • Screwdriver (flathead)
  • Gloves
  • Chock
  • Rollaway jack
  • Jack stand
  • Eye Protective Gear (Goggles)
  • Brake adjustment tool
  • Flashlight

Step 2: Jack Up And Free The Wheel

The first operation to carry out is to park the vehicle on a flat, level surface and choke the wheels. After this, it’s time to jack up the trailer from one side. Set the jack under the frame of the trailer.

Avoid placing the jack beneath the axle. Lift the car off the ground until the wheels are completely off the ground and can spin freely.

Place a jack stand right under the frame to provide extra support. Even with the support, don’t go under the trailer. You can’t completely rely on the jack and jack stands when working on a heavy vehicle.

Step 3: Uncap The Brake Chamber

After jacking up the vehicle, it’s time to gain access to the braking system. Go through the brake chambers and adjustment wheelhouse.

The first thing to do is to take off the brake access cover. With a flathead screwdriver, you can easily uncap the brake chamber.

Usually, most trailers come with this cap that you’ll need to remove to be able to access the brakes. It’s usually located somewhere under the brake drum.

If you can’t easily find it, simply check the brake backing plate located at the back of the vehicle wheel. In some older models of trailers, you may not find the adjusting cap. Depending on the vehicle, you may have layers of these plastic or rubber caps.

Step 4: Push Screwdriver Into The Slot

Insert the flathead screwdriver into the slot after removing the brake adjusting cap. Or you can use the adjustment tool in place of the screwdriver. Turn and pry the adjustment tool handle downwards as you loosen the trailer brakes.

Step 5: Locate The Slot-Bound Star Wheel

The purpose of inserting the tool is to search for and locate the star wheel. By design, the star wheel is a star-shaped component with stuck-out ridges or teeth. You’ll find it at the edge of the wheel.

Once located, the star wheel won’t allow the adjustment tool or screwdriver to slip.

Step 6: Click The Start Wheel And Free The Wheel

Having found the star wheel, you’ll need to further insert the adjusting tool in an up-and-down fashion. This will help you click the star wheel as you hear a clicking sound.

Continue to click the star wheel when you turn the wheel after each click. The process should continue until the wheel is free to spin.

However, even while the wheel spins freely, you should listen for a scraping sound. You can also observe a slight drag. This indicates that the brake pads are correctly engaged.

Now that you’re inserted the tool and clicked the star wheel, you can freewheel to be able to move freely unhindered. The wheel shouldn’t be touching the brake drum.

Even if it does, it should be barely but should spin and move freely. You can re-insert the tool if there’s any obstruction to the wheel’s free spinning.

There’s a precaution you need to take when adjusting the trailer brakes. Stop the process of tightening the adjuster once you feel that the wheel of the trailer won’t turn. What you should do at that point is to pry the tool upward and loosen the adjuster wheel.

Step 7: Clean The Brake Plate And Replace The Cap

Usually when adjusting your trailer brakes, one of the things you should do is to remove any rust buildup. The rust often builds up due to some reasons.

The Northeast is a damp area that can cause rust on the trailer brakes. It could also be that you store the trailer where rain, dew, or water can penetrate it.

If the trailer soaks up in the water, the cast iron of the brake plate will have scaling or rust developing around it. Make sure you rotate the wheel as many times as possible to knock off the scale. Clean the interior to completely get rid of any rust or dust.

Step 8: Replace The Cap

After cleaning the cast and brake plate, you should replace the plastic cover. Tighten the trailer brakes with your screwdriver. Make sure you turn the wheel adjuster and pry it upward to make it tight.

This means that you’ll need to shove down the adjustment tool handle.

What Are Surge Trailer Brakes?

There are two types of brakes in a typical trailer. There are surge trailer brakes and electric trailer brakes. The surge brakes are also called the manual braking system. The brakes are a self-sustained hydraulic braking system.

They use the trailer’s weight to slow down the moving vehicle. They do this by transferring pressure to the trailer brakes. In the process, they compress a hydraulic cylinder.

You can use manual braking in a number of situations. You’ll need a manual braking system when coming down a slope; it’s also useful when towing in high winds. The third situation will be when a large truck is passing by your vehicle.

Ways To Adjust Surge Trailer Brakes

Adjusting surge trailer brakes is as seamless as adjusting the trailer braking system. You’ll need tools such as a flat blade screwdriver, floor jack, jack stands, and two-wheel chocks.

Step 1: Jack The Trailer

You’ll need to jack and lift up the trailer using the floor jack. Make sure you pull over on a flat, level, and dry surface. Before jacking, make sure you check the wheel on the side opposite where you’ll be making the adjustment.

Step 2: Take Off The Inspection Hole Cap

Jacking up the side of the vehicle allows you to access the adjustment hole. You can locate it over the hole near the rearmost wheel. The cover is on the rear side of the brake backing plate.

Remove the cover from its position using a flat blade screwdriver. Put a flat blade screwdriver or drum brake tool into the adjustment hole. This should continue until the screwdriver touches the brake adjusting the star wheel.

Step 3: Rotate The Rear Tire

With one hand, try to rotate the rear wheel in a forward direction. While rotating the tire, use the screwdriver or brake tool to turn the star wheel. The wheel should turn in a clockwise direction. Continue the process until braking pressure gets to the wheel.

Step 4: Adjust The Star Wheel

On five counterclockwise notches, click and back the star wheel off. Turn the wheel and tire freely in a forward travel direction. Make sure.

Take out the screwdriver or brake tool and replace the clip. Make sure the brake tool securely gets back into the inspection hole.

Step 5: Replace The Cover

Return the cover back in place. Lift the car wheels with the floor jack to slide the jack from under the vehicle. Lower the jack and trailer.

Make sure you repeat the same procedure to adjust the brakes on the opposite end of the trailer.

What Are Electronic Trailer Brakes?

When it comes to the electric brakes of a trailer, the working mechanisms are a little bit different. The electric braking system also helps to stop or slow down the towing vehicle.

The braking system connects to three brake components. They are the activating electromagnetics brake drums, brake pads, and electrical signals.

The electromagnetic unit takes power from the vehicle. The unit in turn transmits the power to the brake pads to make them squeeze. The force to slow down the vehicle depends on the amount of power that gets to the brake pads. To slow down or stop a trailer, you will need to apply the trailer’s own weight.

Adjusting the electric brake controller is a bit different from the normal trailer brake adjustment. In your trailer cab is where you’ll locate the brake controller.

Ways To Adjust Electric Trailer Brakes

Here is a step-by-step guide to adjusting the electric brake controller of your trailer. Since much of the activity will be electronic, you won’t need more than the trailer coupler for the process.

Step 1: Attach The Vehicle To A Trailer

Hook the trailer and the vehicle together using the trailer coupler. Once done, the electrical plug should be close to the trailer hitch. Make sure you apply the handbrake of the tow vehicle to prevent the trailer from moving.

Additionally, you can place a wheel stopper or chock.

Step 2: Jack Up The Trailer

Using a standard floor jack, lift the trailer. Place the jack correctly and ensure the jack can withstand the weight of the trailer.

After jacking, inspect to be sure that the wheels can rotate freely. A flat, level and dry parking lot will be a better area to park the car. A deserted road or field is another good option.

Step 3: Take Out The Adjuster Hole Plug

Look under the trailer near the brake unit and remove the adjusting hole plug. If the plug is not removed, you may not be able to ascertain which screw you’ll need to turn.

Sometimes, locating the component may require a flashlight. You may also need to remove up to two plugs before you can turn the screw.

Step 4: Insert The Adjuster Tool

Place the screwdriver or the adjuster tool in the notches. Rotate the tire and ensure it turns freely. Keep the adjuster tool or screw down to allow you to turn the adjuster well.

What you want to achieve is to make the brakes lay hold on the brake drum so that the wheel can slow down. To turn the adjuster repeatedly, press down on the screwdriver bar.

This will allow the adjuster screw to move and shift the screwdriver. Continue the process until the wheel is able to move unhindered.

Step 5: Repeat The Same Process

After adjusting one side of the electric brake wheels, you can turn to the other. Simply lower the trailer jack to work on the other wheel. After adjusting the brake on the other side of the trailer wheel, it’s time to run a test to see how well the brakes will run.

I found a great video for you to watch below:

How To Test Out Truck And Trail Brake After Adjustment

How To Test Out Truck And Trail Brake After Adjustment

After adjusting, you’ll need to perform a test to assess the trailer brakes.

  1. Start by driving the vehicle at forty miles per hour (40 mph).
  2. Press down on the manual level to slow down or stop the trailer and truck.
  3. Don’t engage the truck brakes.
  4. Repeat the process many times (30) to allow the brake pads and electromagnets to sit well in the brake drum.
  5. If you’ve done proper adjustments, you should feel that the brakes are working well.
  6. You should tighten any loose screws to ensure the brakes work correctly.


What Type Of Trailer Brake Controller Should I Install?

Both the surge brakes and electric brakes need a trailer brake controller to work. It doesn’t matter if they’re old or replacement brakes. The process is the same. The brake controller regulates the amount of power that the electric brakes receive.

It doesn’t matter the speed of a tow vehicle or trailer, it needs enough power to slow down or stop it. You need the entire braking system and not only the trailer’s brakes to bring it to a halt or slow it down.

Drivers can activate the two brakes on their vehicle using the brake controller. The controller enables the driver to monitor the activity of the trailer brakes.

Generally, there are two types of trailer brake controllers. We have inertia-based and time-based trailer brake controllers. The working mechanism of the inertia–based or proportional brake type is simple.

These brakes work with the electrical part of the brake to sense the momentum of the tow vehicle. They use an accelerometer to also know how idle the vehicle is.

Once you activate the brakes, the controller sends the pressure out. The amount of pressure the trailer brakes receive depends on the inertia of the vehicle.

The time-based brake controller works on the principle of pressure. The trailer braking system receives pressure to slow down or stop the tow vehicle.

The time to activate the brakes of the trailer depends on the driver and what settings they initiate. The inertia-based brake type comes with more precision than its time-based counterparts.

Can I Tow Trailer With Trailer Brakes?

No, it’s difficult to tow without having brakes on your trailer. Overall, it all depends on the gross weight of the vehicle and the speed with which the truck tows the trailer.

If the weight is less than 3000-4,000 pounds, you may not need to bother about the lack of brakes. But if it exceeds that threshold, your trailer should have brakes.

Again, towing at a speed exceeding 30 miles per hour (mph) requires that the trailer has brakes.

How Often Should I Adjust My Trailer Brakes?

On average, you should adjust your trailer brakes every 3 months or 3000 miles. It all depends on how often you tow your trailer.

Ensure proper maintenance of both the truck and trailer. This way, you can reduce the interval of adjustment of the trailer brakes.

How Do I Tell If My Trailer Brakes Are Working?

The easiest way to tell if the brakes are working on the trailer would be to engage the manual lever. Ask someone sitting outside the vehicle to help you watch the trailer wheels closely.

The brakes should begin to drag after you gradually lift your foot off the brake pedal of the tow vehicle. Otherwise, they will need you to adjust them.

The trailer braking system may not work when you indeed think it’s. But it depends on the kind of testing you want to do. There are electric and manual brakes.

Can Trailer Brakes Self-Adjust?

Yes, trailer brakes can self-adjust. Sometimes you want to either tap the brakes or back them up. Either method will do the job. Trailer brakes may also need you to adjust them from time to time using the manual method.

The lack of cable in the brake assemblies forces the use of the manual braking method. The method to adopt will depend on the model of the vehicle’s assemblies that are installed on your trailer.

You can check if your trailer comes with self-adjusting units or not. One of the easiest ways to do this is to the drum or hub of the trailer axle. This way, you can tell if the vehicle comes with an adjustable cable.

Generally, the cable often extends across the brake assemblies. Once you step on the brake pedal, the self-adjusting units will adjust themselves. You can adjust the brake assemblies as soon as you install the new brake units on the car to avoid issues.

Final Thoughts

Adjusting trailer brakes is an important aspect of driving or towing. The risk involved in towing a trailer can be daunting. If not properly done with a quality braking system, a trailer tow vehicle can face an uphill task.

You should take your safety seriously. Without the brakes, you can also endanger the lives of other commuters.

Many states need that you install trailer brakes in your vehicle because of its gross weight. The gross weight range limit varies from state to state.

A trailer with 3000 pounds of gross weight will have to come with an efficient braking system. Some other states put the minimum gross weight at 1500 pounds. As a driver, you should study the legal requirements of your state of residence.