What Causes Drum Brakes To Lock Up?

Are drum brakes an important component for cars? What causes drum brakes to lock up, and what problems can it create for the driver? We answer all of these questions in detail in the article below.

Drum brakes and disc brakes can become locked up while driving. There are many reasons behind this. If the car has a brake problem, it is crucial to diagnose the brake problem and then fix it. 

If you have a brake problem while driving, it should be your first priority to deal with the problem. There are several reasons for drum brakes (which are usually in the rear) to lock up: 

  • Improper adjustment of the parking brake/service brake
  • Incorrect adjustment of the brake shoe
  • Malfunctioning rear brake springs
  • Poor quality brake fluid, 
  • Faulty ABS material, 
  • Broken brake drums. 


What Causes Drum Brakes To Lock Up


What Are The Types of Brake Lock Up?

Brakes can be locked up in two situations: hitting the brakes too hard or not hitting them hard enough. 

Brake Drag

You can call the first scenario a brake drag or self-application. Brake drag is far too common these days. Residual hydraulic pressure activates the calipers and locks the brakes, even though you have not pressed the drum brake. 

Never ignore this type of problem, as it causes more mechanical failure, such as problems with other parts of the braking system. 

Brake Lock Up

You can call the second scenario, the brake lock-up. It happens when you brake too hard or brake too softly to avoid an accident. 

The power to apply the brakes can activate the full stopping power of the brakes, which helps you to come to an abrupt stop. In this case you have the possibility of skidding. When that happens, the brakes lock up, and the car becomes difficult to control.  

Important choice by which you can avoid accidents

If you encounter a brake drag or brake lock-up, contact a Service Center as soon as possible. In these situations, the technicians of the service center can ask you some questions like which brake is locked up and why. 

This information will help them to get the job done correctly. If you encounter a lock up while on the road, you can get the three choices by which you may avoid accidents:

  • Press the brakes and try to control as much as possible. If the car has an ABS or Anti-lock Braking System, you might feel that the stopping of the car is not as quick as you expected. ABS is an integral part of the car, which will prevent the wheels, and brakes from locking and, of course, will also prevent skidding.
  • During this time, you should keep the foot away from the brake pedal to get enough traction to unlock the wheels. Then re-apply pressure to the drum or other brake if needed.
  • Press the brakes repeatedly and as fast as possible until the brakes are off or the car takes you to a safe place.


You might like to read: Why Would A Brake Caliper Lock Up?


What Are The Causes of Drum Brake Lock Up?

Although brake lock-ups are no longer common now because of modern ABS brakes,  in earlier days, such problems occurred quite frequently. Most of these problems used to arise due to wear and tear of the brake system components. There are also many other problems for which drums or other brakes are locked up.

The most common cause of sudden drum brake lock while driving.

  • Using unsuitable brake fluid
  • Brake system components becoming overheated
  • Worn or damaged brake pads, calipers and rotors, shoes, wheel cylinders
  • Applying the emergency brake during an accident
  • Holding the brake caliper or wheel cylinder

What To Do When Your Brakes Lock Up While Driving?

While driving, the experience of drum or other brake lock-up can be harrowing. So you have to follow some basic steps so that the situation does not worsen. These steps are as follows.

#1 You should never panic during a brake lock-up

If you panic about any problem, you will not be able to get out of this problem. The same is true of brake lock-ups as well. It is important not to panic if you are experiencing brake lock-up. 

However, this is easier said than done. If you have other passengers in the car, you have to do everything to protect them, so you must not panic. Panic robs you of the ability to think for the right time at the right time.


What Causes Drum Brakes To Lock Up


#2 Try to find a good place to Stop

The next step to consider is to find a safe place where you can stop your car after brake lock-up. Quickly scan your surroundings to determine what is he best location near you. A parking lot and a wide driveway may be suitable places in this case.

#3 You should carefully exit the roadway

Once you have decided where you need to stop, the next step is to get off the road as carefully as possible. This is extremely difficult to do at the moment of drum or other brake lock-up because there is a lot of traffic around.

If you have to enter a lane, signal if possible. Remember, you need to make firm decisions at this point; otherwise, the situation can be very dire.

#4 Come to a Stop Using Parking Brake if Necessary

When you drive off the road, you should stop your car as carefully as possible. If you feel that the vehicle is not slowing down, pulling to one side or the other, consider setting the emergency brake that will give you some stability.

However, it is essential to remember that setting the car’s emergency brakes at high speeds can be dangerous.

#5 Pull the car to a Repairing center as soon as possible

You should stop driving unless the vehicle is repaired correctly after experiencing a drum or brake lock-up. If possible, you have to pull your car for repair along with the brake lock-up if the service center is a short distance from the vehicle’s location.


You might like to read: What Causes A Tire To Lock Up


What To Do After Locked Up Brakes?

After a drum or other brake lock-up event, you need to determine the root cause of the failure. It is advisable to conduct a thorough visual inspection.

#1 Inspect the signs of irregular wear brake and its component: 

All vehicle brakes need to be inspected based on their signs of irregular wear brake and damage to components. If they discover any defect during the inspection, it should be repaired first to return the car’s service.

#2 Check the burning odor or excess dust or blue on the brake drum.

In many cases burning odor on the drum brakes, excess dust, or sudden turning of the brake rotor or blue of the drum can cause lock-up. If you notice any of these symptoms, try replacing the drum or other brake components on the wheels.

 #3 Replace the brake pads

Moreover, some people want to replace the similar components found on the opposite wheel end of the same axle. Finally, you also have to replace the brake pads in pairs.

#4 Replace the wheel bearings

In some cases, overheating can cause brake lock-ups that can damage the wheel bearings on the wheels. So it is essential to replace it.


What Causes Drum Brakes To Lock Up


#5 Check all brakes before you drive again.

Before driving, even after repairing everything, you should have a preliminary check of the brakes in an isolated area, such as a parking lot or driveway.

#6 Conduct an experimental drive

If you think all the components are in the proper operating condition, you can conduct an experimental drive on the car before getting out on the road. It makes it clear if there are any additional problems with the vehicle. So, an experimental drive is crucial for evaluation.

#7 Take the second opinion: 

If, for any reason, you are unsure about repairing a car’s drum or other brake lock-up, be sure to consult a professional. There is no shame in asking for a second opinion from anyone.

After all, the life of the car depends on the performance of its brake system, which you must adhere to.


You might like to read: What to Do if Brakes Lock Up When Car Is in Reverse?


Frequently Asked Questions

#1.  What causes drum brakes to lock up?

The drum brake is one of the important components of the car, which is vital to be in proper operating condition.

The most important of the common causes of drum brake lockup is service and/or parking brake adjustment. If any of these adjustments are not made correctly, the brakes can become very sensitive and you may experience a brake lock up.

#2  What causes rear brakes to lock up?

There is a long list of causes that make rear brakes lock up. Some of the causes are

  • Improper brake fluid
  • Overheated braking system
  • Defective ABS parts
  • Damaged or broken drum brakes


What Causes Drum Brakes To Lock Up


#3 Why do my rear drum brakes lock up? 

There are lots of reasons of rear drum brakes lock up. Some of the important things are Improper parking brake/service brake adjustment, malfunctioning rear brake springs, faulty ABS system, broken brake drums, and others. If you experience any of these issues, you have to send the car to the service center.

#4 Why do my rear drum brakes over adjust?

Drum brakes need to be adjusted to compensate for the normal wear of the brake. but you over-adjust the brakes, it becomes locked up, or you have to activate it with little pressure on the brake pedal.


You might like to read: Why Are My Trailer Brakes Locked Up When Plugged In?


A Few Final Words

Drum brakes are very uncommon these days, but many times older cars can still have drum brakes. You need to take proper care of these brakes because they are liable to locking up more than disc brakes. We have mentioned some of the reasons why your drum brakes might lock up. Thank you for reading the article, and if you have any further doubts, please reach out to us in the comments section below.

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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