How to Adjust Drum Trailer Brakes (Electric, Mechanical)

Some people get confused when trying to adjust their brakes. Often they listen to the wrong people and have their brakes adjusted in the wrong manner. Unless the brake shoe is touching the drum, it will not work properly

Adjusting brakes is a moderate task. All you need are a few tools to make sure the shoes are aligned and touching the drum for them to work right. Any method that does not provide this result should be discarded and ignored.

To learn more about how to adjust your brakes, just continue reading our article. It will provide instructions for those who are not licensed, mechanics. Take a few minutes to see how the following information helps you with your brake adjustments.

When To Adjust Trailer Brakes


When you get new brakes, you need to wait till they get seated first. That usually occurs at about the 200-mile mark. You can do it yourself, after reading the directions, or you can go to a mechanic to have them adjusted.

Then you should adjust them at every 3000-mile intervals. Or you can adjust them based on performance and use. These are not hard and fast rules but basic guidelines to follow.

You may go over or under the limits set here as driving is not an exact science. Just try to keep it close to the mark as possible. If you go more than 3000 miles it won’t hurt the brakes at all. Just do it as soon as possible after you reach those specific markers.

If you have a regular mechanic, they should let you know when you should adjust your brakes. One sign that you need an adjustment is when your emergency brake handle goes up too easily.

That will be a sign that you need to adjust those brakes.

Can You Adjust The Trailer Brakes By Backing Up?

This may be something you can do if your vehicle has auto-adjusting brakes. To know if you have auto-adjusting brakes or not, you need to remove the drum from the spindle.

Then you look for an adjustable cable. If you see the cable then you have self-adjusting brakes. If you don’t, then you have to adjust your brakes by hand.

While some people have had success at adjusting their brakes by backing up, this is usually done on those vehicles with self-adjusting brakes. Then they do it as the self-adjusters are not the best in the world.

All you do is find a nice incline, back up, and then hit the brakes hard. That should do the trick. This method does not always work and if it doesn’t work for you, then go to your mechanic and have them do it.

They have the experience needed to make sure your self-adjusting brakes are adjusted right. Backing up is not a guaranteed to work method.

How To Adjust Electric Trailer Drum Brakes


The first steps will be the same no matter what type of brakes you have on your trailer. Make sure the triers are chocked so that they will not roll on you. Then jack the axle up high enough so that the tire has room to spin. You do not need to go very high.

Once the tire is in place, you need to use a flat head screwdriver to remove one or two of the caps. Underneath those caps will be an adjustment screw. Now you start to spin the tire and keep it spinning while you use a flat head screwdriver to adjust the adjustment screw.

Keep spinning the tire and adjusting the screw until you hear or feel the tire starting to drag. Then stop the adjustment at that point. Put the caps back on, and then lower the tire.

After you do one, make sure to do the rest of the tires in the same way. You just need a slight drag to have those brakes work right.

Adjusting Drum Trailer Brakes

This task takes a little time so be patient and make sure you do the chocking and jacking right. Have a block of wood, usually a 2 x 12, or 2 x 10, or a 2 x 8 underneath the jack for stability.

Then make sure the other tires are chocked so they will not move on you as you are under the trailer. Then gather your tools together. Depending on the type of brakes your trailer has, you may not need all of these tools:

- A flat head screwdriver

- A Phillips head screwdriver

- A hammer

- A chisel

- A brake latency tester

- A rollaway jack or a bottle jack

- Gloves & Safety goggles

Once your tools are in place, you can do the first two steps already mentioned. Place the jack in the right spot and that is usually not the axle. You do not have to jack up too much. Just go high enough for the wheels to spin.

As long as you work carefully and safely, you should be fine.

Trailer Brake Adjustment Direction


The electric brakes have the wheels spinning in a clockwise direction. The adjustment screw is also spun in the clockwise direction. It is hard to see as the adjustment screw is inside the wheel and you only have that little space the caps cover to look through.

You have to work carefully here as adjusting the brakes is a precision act. If you get too much drag the brakes won’t work. If you get no drag, then the brakes won’t work properly.

You have to do this just right to make sure your brakes will work like they are supposed to. Keep spinning till you feel that drag and then move the adjustment screw slightly to get the precise spot your brakes need to be.

Once you do one adjustment, you should be an old pro for the next time around. If you make any mistakes, just correct them and get the brakes to the right point.

How To Adjust Hydraulic Trailer Drum Brakes

The process is not that much different from adjusting your electric brakes. The only difference may be that you would need a brake adjusting tool instead of a screwdriver. That change will depend on your style of hydraulic brakes.

Once the tire is in the air and all other tires are chocked so they do not move, locate the adjustment holes. There should be one on each side of the assembly. Remove any caps so you can get the adjusting tool inside to rotate the star wheel.

Rotate that star wheel to get the drag you need and then put the caps back, lower your tire and move on to the next wheel. Some instructions say to adjust the brakes until it matches the teeth on the star wheel.

Just turn the star wheel until the brakes stop the tire from spinning. Then back it off till you only get a slight amount of drag. Then you are done and just need to finish adjusting the other brakes on the other tires.

How To Adjust Mechanical Drum Brakes On a Trailer


This task is basically the same as the other two we have already described. Jack up the tires, chock those wheels and get underneath your trailer. You have to go underneath your trailer as the adjustment screw is on the back side of the wheel.

To apply drag to your brakes you need to turn the adjustment screw clockwise. To lessen the drag, you need to turn it counter-clockwise. It takes a little time as you have to reach inside the wheel with a screwdriver or an adjusting tool to make these turns.

You won’t be turning it like you would an exposed nut or screw. The turning goes a little bit at a time. While you are doing this adjustment, you need to spin the tire or the wheel (if you have removed your tire).

The moving tire will let you know when there is the right amount of drag from the brakes. If you go too far, the wheel won’t spin freely. This means that you need to back the adjustment screw off a little way.

It takes a little time but it is not difficult to do. It requires a steady hand but not a lot of force to turn that screw.

Some Final Words

Adjusting your trailer brakes is not the most difficult task you will do with your trailer maintenance. It is a necessary task that requires careful work as you do not want too much dragon those wheels.

The hardest part will be locating the adjustment screw and getting the right tool inside the small space to make the adjustment. There is no trick to doing this task either. You just have to turn the adjustment screw until it is in the right position.

Just be careful raising and lowering those tires so you don’t hurt yourself.

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