Sticking Brake Calipers: Symptoms, Causes & How to Fix It

Are you having trouble with your brake calipers? You’re not alone. Brake calipers are responsible for applying pressure to the brake pads, which causes them to move and squeeze against the rotors in order to slow your vehicle down. Without brake calipers, a car would not be able to stop safely. However, brake calipers are commonly known for sticking, and most car owners will experience this at one time or another. But why is that?

In this article, we’ll not only discuss that but also go over the symptoms and how you can troubleshoot and fix sticking brake calipers. Finally, we’ll also cover how you can prevent your calipers from sticking in the future. Let’s dive into it!

What are the Symptoms of Sticking Brake Calipers?

1. Uneven brake pad wear

It’s not always obvious if you have a sticking brake caliper. But if you notice or your mechanic mentions that your brake pads are wearing unevenly, it could be a sign of a sticking brake caliper. This prevents the brake pads from applying evenly to the rotors, which can lead to uneven wear on the pads. 

If you drive with uneven brake pads, you may notice vibrations in the brake pedal or your steering wheel shaking as you brake.

Also read: 6 Signs When to Replace Brake Pads

2. Reduced Braking Power

If your brakes don’t seem to be working as well as they used to, it’s also a sign of a sticking brake caliper. When the caliper sticks, it can prevent the brake pads from applying efficiently to the rotors as they should, which can reduce the overall braking power of your vehicle. This can be dangerous, as it can take longer to stop your vehicle, which you don’t want to experience in an emergency. 

3. Vehicle Pulling to One Side

If it feels like your car is pulling to the side of the road when you apply the brakes, it could be a sign of a sticking brake caliper. This can both be uncomfortable and dangerous, and if anyone else is driving your car, it’s a good idea to let them know about this.

4. Dragging Brake

Have you noticed significant decreases in performance and fuel efficiency lately? Dragging brakes means the brake pads remain in contact with the rotors even when the brakes are not applied, and you may feel like your car is “dragging.” This will for sure give you more trips to the gas station. But not only that, if you keep driving, chances are your brakes will overheat, warping your rotors. And in the worst case, it can even cause a fire.

5. Burning Smell or Even Smoke

If a burning smell hits your nostrils as you drive, it’s always a cause for concern. Although several things can cause a burning smell, it’s also a common result of dragging brakes. It means the brakes are overheating, which can happen if the brakes are being used excessively or, in this case, if the brake caliper is sticking.

As mentioned, this can cause the rotors to become warped and even cause a fire, so if you see any smoke coming from your brakes, immediately pull over to the side of the road and have your car towed to a preferred repair shop.

What are the Causes of Sticking Brake Calipers?

Various factors can cause a sticking brake caliper, but most often, immobility, damp climate, and corrosion in the caliper pistons is the culprit of the problem. For example, If your vehicle sits for long periods of time without being used or if you leave the handbrake engaged for extended periods, chances are the brake caliper may become stuck and require attention

Here’s a more detailed list of causes of a sticking brake caliper:

1. Rusty Caliper Pistons and Damaged Piston Boot

Through the hundreds of brake repairs I have done over the years, a rusty caliper piston is the most common cause of a sticking brake caliper, usually caused by a damaged piston boot.

The caliper pistons are responsible for applying the brake pads to the rotors when the brake pedal is pressed. The piston boot, also called piston dust seal, is a flexible rubber or plastic cover that fits over the piston and is known to get damaged or brittle and crack.

This will cause moisture, dust, and other particles to find their way into the piston and cause it to start rusting. This will eventually prevent the caliper piston from moving freely and applying the brake pads evenly.

If not taken care of, eventually, the piston will stop moving completely, and you’ll end up with brake pads stuck to the brake disc.

2. Rusty And Stuck Brake Pads

Rusty and stuck brake pads are also one of the most common causes. Brake pads should be able to glide forth and back on the caliper bracket easily. However, when these bracket slides start to rust, it can cause the brake pads to push against the brake disc. This can reduce braking performance and wear on other brake system components.

3. Dirty Caliper Guide Pin

Caliper guide pins are small pins that help guide the caliper as it moves back and forth to apply the brakes. Over time, these pins can become dirty or corroded, causing them to stick and preventing the caliper from moving freely. This can cause the brakes to drag and lead to uneven wear on the brake pads.

4. Parking Brake Cables

If the sticking brake caliper is on the car’s rear, you may have a problem with the parking brake cables since some modern cars have the handbrake on the brake caliper instead of the brake disc. 

As the parking brake is applied, the cables pull on the brake calipers, causing the brake pads to press against the rotors and prevent the vehicle from rolling as you park. These brake cables are typically made of steel and are designed to be strong and durable. 

However, as it’s made of steel, it can also start to rust if moisture gets into the wires. This can cause them to become stuck by rust or even freeze during cold days, making it difficult to move. This results in the brake caliper not letting go as you release the handbrake.

5. Broken Brake Hose

This is not a very common problem, but in rare cases, a broken brake hose can cause a sticking brake caliper. The brake hose is the part of the brake system that allows brake fluid to flow to the calipers and back to the master cylinder. If the hose is damaged, it will prevent the brake fluid from returning to the master cylinder, resulting in the brake caliper sticking. 

6. Dirty or Old Brake Fluid

Over time, brake fluid can become contaminated with moisture and other contaminants, which can cause it to become less effective. This can also cause the brake system to rust from the inside, leading to a sticking brake caliper. A sign of contaminated brake fluid is a spongy feeling when pressing the brake pedal.

How to Fix a Sticking Brake Caliper

Fixing a sticking brake caliper can both be easy and very complicated. But before scheduling a time at the repair shop, there are a few things you can do to try to determine the cause and maybe even fix it. However, don’t take water over your head, and always refer to a professional mechanic if there’s something you are unsure about.

Troubleshooting the Cause

To determine the problem, the best way to start is by a visual inspection and then move on from there.

  1. Start by jacking up the vehicle and remove the wheel to access the sticking brake caliper. Ensure the car is stable and that you use safe jacks. 
  2. Next, inspect the overall condition of your brakes, such as wear, damage, or rust. This includes the brake pads, brake caliper, guide pins, piston boot, and the arm on the back of the caliper to which the park brake cable is attached to. If you see any visible signs of rust or damage, that’s where you want to start.
  3. If you still don’t know what is causing the problem, move on to checking the brake hose. To check for a brake hose restriction, you’ll need to carefully open the bleeder screw on the top of the caliper (usually covered by a rubber cap) and see if the brakes bleed. While at it, check the condition of the brake fluid.

Fixing the Problem

Rusty piston: If there’s a little rust on the caliper piston, you can try to lift the piston boot and push the piston out a little to try to clean it. Make sure the boot is in good condition and do not forget to replace it, which often is difficult without the knowledge.

Rusty and stuck brake pads: To fix stuck brake pads, you need to remove the slide bolt and pivot the brake caliper up. You may carefully need to use a rubber mallet if the brake pads are stuck in the brake pad bracket. When the brake pads are out, make sure they are in overall good condition. If so, you can try to clean them with a file or sandpaper and then lubricate them where they attach the bracket. If the brake pads are thin or there are any signs of uneven wear, you should replace them.

Dirty or rusty guide pins: If the culprit instead is dirty or rusty guide pins, you can try to clean and lubricate them. However, they can be extremely hard to remove, so you may need to use a torch to loosen them up.

Stuck handbrake: For a stuck handbrake, the only thing you can try is lubricating the handbrake cable and the mechanical arm on the caliper to which the park brake cable is attached. Continue by moving the arm back and forward a few times. If the brake caliper still doesn’t release, you may have to replace the cables or the caliper.

Broken brake hose: If you tried everything else and you’ve checked the fluid restriction by checking if the brakes bleed. It’s probably necessary to replace the brake hose.

Contaminated brake fluid: If it is in bad condition, you need to have it flushed and changed. Checking the condition of the brake fluid is often very simple and something you can do yourself. The color of it should be light brown and clear and should under no circumstances be dark brown.

Replace the whole caliper: The last thing to do is replace the whole caliper. As it’s often not very expensive, it’s usually a better choice than trying to renovate it. If you plan to do this yourself, keep in mind that most times it’s also necessary to bleed the brake system after a caliper replacement.

How to Prevent the Brake Caliper From Sticking

There are several steps you can take to prevent the brake caliper from sticking:

  • Regularly check and change the brake fluid: Most manufacturers and mechanics recommend changing the brake fluid every two years or 30,000 miles, whichever comes first.
  • Clean and lubricate your brakes: It’s recommended to maintain the brakes every 15,000 or two to three years to prevent most brake problems. This includes inspecting and cleaning the brake pads, rotors, slide pins, caliper pistons, and rubber boots.
  • Give your brakes a hard brake sometimes: Yes, that’s right. A common misconception is that you should brake as little as possible to extend your brake pads’ life. In reality, giving your brakes a hard brake occasionally at high speeds can prevent this issue and also help your brake pads to properly seat against the rotors, ensuring optimal contact. But do not brake too hard!
  • Avoid engaging the handbrake for extended periods: Leaving the handbrake engaged for long periods can cause the brake caliper to stick. But don’t get me wrong, you still want to use it to keep the parking brake or bracket in motion – even if you have an automatic transmission.

Can You Drive with a Sticking Caliper?

In short – no, driving with a damaged brake caliper is not safe unless it’s absolutely necessary. Continuing to drive with a sticking brake caliper for too long can cause additional damage to the brake pads and result in dangerous situations on the road. 

To ensure the safety of you, pedestrians, and other drivers on the road, it is important to have a sticking brake caliper repaired or replaced as soon as possible. The brake pads can grind away, potentially damaging the brake disc and causing intense heat. This heat can damage surrounding parts of the vehicle and even cause a fire.

The Conclusive Conclusion

Now that you know everything you need about sticking brake calipers, it’s up to you to figure out if this is your problem. The culprit behind sticking brakes is often immobility, damp conditions, and corrosion. But by visually inspecting them, you can get an overview of the condition of your brakes, and many times, it’s enough to figure out what is going on.

By following a few simple tips in this article, you can prevent your brake calipers from sticking in the future. And always make sure to maintain your brakes according to the manufacturer’s recommendation.

Thanks for reading!

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Rickard Cefalk

Rickard is the owner of and a dedicated and avid do-it-yourselfer who has always enjoyed working on his own vehicles since childhood. He now devotes his time to sharing his expert knowledge of car maintenance and other car-related information through his website.

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