Why is My Brake Calipers Sticking When Hot?

Did you know that brake failure accounts for 300,000 crashes per year? Brake failure while driving is probably one of the most terrifying things a driver can experience. But before the brakes can fail, there are warning signs that will indicate issues with your brakes.

Chief among them is seizing or brake calipers. Keep reading to learn how to detect brake caliper failure and what you should do if your brake caliper is not releasing.

Symptoms of a Stuck or Frozen Brake Caliper

Here are common signs of brakes sticking while driving. If you’ve experienced these symptoms, you have brake caliper sticking problems.

Vehicle Pulls to One Side

With a stuck or seized brake caliper, your car will tend to pull towards the side that has the sticky caliper. It will be similar to if you had a bad alignment but usually more serious. This will happen not only when braking but when you’re simply driving.

Continuing to drive when your vehicle doesn’t stay straight is incredibly dangerous. Instead, hire a professional mechanic.

Car Slows Itself Down

When you have a sticky brake caliper or calipers, they are often at the point where they are making your brake pads have constant contact with your brake rotors. This makes it feel like you are braking even though your foot isn’t on the brake pedal.

In addition, you will quickly wear through brake pad material which can result in high pitched sounds or grinding after enough brake pad material is used up. Finally, confirm that your brake calipers are not stuck; otherwise, replace the caliper or any related parts.

Bad Gas Mileage

Having a bad fuel economy can result in many different problems, including your calipers. As mentioned above, a stuck caliper will result in unintended braking, making your engine work harder to keep at its speed, resulting in more fuel being used.

Excess Heat from Wheel

Because a frozen brake caliper will be applying constant pressure to the back of the brake pad, which in turn applies constant friction to the brake rotor, heat is a result of this friction. Therefore, the longer you drive with a stuck brake caliper, the hotter it will get in that area.

If you do a slow walk around your vehicle after stopping, you should notice extra heat coming from a specific wheel if you place your hand near it. Hot brake calipers are a common sign of stroke or seizing brake caliper.

Note: You may also notice the brake pedal not coming back up after taking your foot off it.

What causes brake calipers not to release?

Here are some reasons why your brakes drag when hot;

Rusty Caliper Pistons and Piston Boot

The caliper pistons are an essential part of the brake system. They are pushing the brake pads against the brake disc to make the car reduce the speed. In addition, the brake caliper pistons have a rubber boot around them to prevent dust and other particles from coming into the brake system.

It is quite common for this boot to get damaged, and water and other dust will come into the piston. This will cause the piston to start rusting, and finally, it will stop moving completely – which will cause the brake pads to get stuck against the brake disc. Check for any damages around the caliper boot and replace it if needed.

Rusty Brake pads

The second most common sticky brake caliper cause is rusty brake pads. The brake pads have their guides, which should be lubricated for the brake pads to glide forward and backward on the brake caliper bracket easily.

When dust and rust get collected on these bracket slides, the brake pads will get stuck in the brake pad bracket and push at the brake disc. To fix this, you have to remove the brake pads, clean the brake pad bracket with a file or sandpaper, and lubricate it with copper paste or something similar.

Dirty Caliper Guide Pin

The brake caliper guide pins are located at the brake caliper bracket and help the caliper slide forward and backward when braking. However, the guide pins will get stuck by rust, which will prevent the brake caliper from functioning properly and, therefore, cause sticking brakes.

These guide pins have rubber boots to protect them from water and dust. Check the rubber boots and remove, clean, and lubricate the guide pins again.

Parking Brake Steel Cables

If your sticking caliper problem comes from the vehicle’s rear, there is a big chance of a problem with the parking brake. Many modern cars do not have the handbrake inside of the brake disc but on the brake caliper. As a result, water and other dust can come into the handbrake wires and cause them to rust.

This will cause the brake calipers not to release properly when you release the handbrake. To fix this, lubricate the handbrake cable and the arm on the caliper and move it backward and forward a hundred times to see if it gets better. Of course, you have to replace the parking brake cables or the caliper in the worst case.

Broken brake hose

The brake hose allows brake fluid to flow to the braking system and back to the master cylinder. However, if there is a small breakage in the brake hose, the brake fluid will flow to the brake pistons but not back.

This will cause the calipers to stick. This is not a very common problem, but I have noticed it in some cars. If you have tried everything else and the problem still insists, you should try replacing the brake hose.

Dirty or Old Brake Fluid

Dirty or old brake fluid is the main cause of many brake problems. Brake fluid is drawing water from the air, and therefore it should be replaced every 1 or 2 years. If you are not replacing it, it will contain a lot of water, which will make your brakes rust from the inside.

Brake Caliper Slides

Each caliper has grooves where the brake pads slide into when you step on the brake pedal. When you take your foot off the brake pedal, the pads slide out of the grooves.

If there is debris or corrosion built up in the grooves or on the brake pads, the pads will get stuck in those grooves.

Brake Caliper Bolts

Caliper bolts are made to slide, and they can become sticky if they are too dry and not lubed up periodically. In addition, the bolts are made with a protective rubber layer to trap the lubricant inside the bolt, but this rubber can easily tear and cause the lubricant to spill out.

Once the bolt dries out, it will cause rust and debris to build up, further deteriorating the sliding mechanism it has.

How do you stop a brake caliper from sticking?

Do this to prevent your brake calipers from sticking;

  1. Changing brake fluid every 1-3 years will prevent the brake system from rust corrosion.
  2. Clean the brake pads, guide pins, and pistons every 2-3 years. Or when you replace your brake pads or brake discs.
  3. Brake hard at high speeds. If you never use the brakes hard, they will get stuck after a while.
  4. Use your brake several times per year to prevent them from getting completely stuck.

How to Fix a Sticking Brake Caliper

Brake calipers push the brake pad onto the rotor, forcing the wheel to slow down. Calipers use sliding pins and grooves to move the brake pad back and forth. The main reason brake calipers stick is debris or grease build-up.

Items needed:

  • Car or Tire Jack
  • Lug Wrench
  • Caliper and Brake Grease
  • Socket Wrench Set
  • Rags
  • Brake Cleaner

1. Jack Up the Car to Access the Wheels

First, identify which brakes you think are sticking. These are the wheels you need to pick up off the ground. Then, begin by placing the jack under the car or wheel according to the jack manufacturer’s directions.

For safety, place chocks behind the other wheels so that there is no possibility of the car rolling while you are working on the brakes.

2. Remove the Wheel

Next, remove the wheel with the lug wrench. Place all the bolts nearby in a space you remember where they cannot roll away. Then, remove the wheel by hand and set it next to you.

3. Clean the Brake Pads

Use a heavy-duty brake cleaner and spray it thoroughly on the exposed brake pads and linings according to the package directions.

4. Remove the Brake Caliper and Pads

Now that the brakes are clean, remove the calipers and pads. Do this by unbolting the calipers and lifting them up and away from the bracket. This gives you access to the brake pads, which you can remove by hand.

5. Cleaning the Brake Caliper Itself

Next, you want to get any old grease or lubricants and any dust build-up off of the brake caliper. Use a brake cleaner combined with your rag to scour the caliper.

Note: the caliper pins or bolts have a rubber boot on them. Inspect them to check for any tears. Any damage to the rubber boot can allow excessive dirt and build-up into your calipers. You should replace any parts that are too corroded or dirty to clean.

6. Lubricate the Brake Calipers, Pins, and Slides

Then grease the calipers using a caliper-specific lubricant. Ensure all the bolts, pins, slides, and pistons are fully greased to prevent more dust build-up and allow smooth sliding.

7. Put the Calipers, Brakes, and Wheels Back On

Then place the brake caliper back into its bracket. Thread the caliper bolts back into place. Do not overtighten these bolts. Overtightening can cause things to crack, damaging your brakes, pads, and calipers.

Next, reinstall the brake pads, making sure they are adequately secured. Place your tire back onto the axle and tighten the lug nuts. Again, do not overtighten the lug nuts as this can cause damage to the wheel. Check your owner’s manual for the correct tightness settings.

Other Troubleshooting Ideas for Sticking Brake Calipers

Here are other potential problems occurring if your brakes are still sticking.

Your Emergency Brake Is Worn Out

In some cases, your emergency brake or parking brake is attached to the rear brake calipers. In this case, a worn-out brake line could be pulling on your calipers incorrectly, causing your brakes to stick.

The Brake Hose is Leaking or Torn

If you have any breakage in your brake hose, the brake fluid will flow into the brakes but not out instead of flowing back out to the master cylinder.