Brake calipers engage the brake pads, forcing them to secure the brake rotor. Once you release your brake pedal, the brake pads should disengage, allowing the rotor to move freely.
But this doesn’t always happen.
It’s possible that you’re experiencing brake caliper sticking — but what does that mean, exactly?
In this article, we’ll answer that question.
We’ll also look at the potential causes of stuck brake calipers, the symptoms involved, how to diagnose and fix a stuck brake caliper, and answer some common FAQs.
This Article Contains
- What Does It Mean When You Have “Brake Caliper Sticking”?
- What Causes a Brake Caliper to Stick?
- What Are the Symptoms of a Sticking Brake Caliper?
- How to Diagnose and Fix a Stuck Caliper?
- 4 FAQs About Sticking Brake Calipers
What Does It Mean When You Have “Brake Caliper Sticking”?
Essentially, the brake pads are still in contact with the rotor while the wheel is turning. This leads to constant friction and brake drag.
Brake calipers can get stuck on both the front and rear wheels. However, most economy cars usually have rear drum brakes instead of disc brakes (meaning the brakes don’t feature a rear caliper). In that case, only the front brakes will experience caliper sticking.
Now that you know what brake caliper sticking is, let’s investigate why it happens.
What Causes a Brake Caliper to Stick?
There are many components to your car’s brakes.
Here are some brake issues that may result in a sticky brake caliper:
1. Worn or Faulty Brake Caliper Bolts
There are two ways the brake caliper bolts can cause a sticky caliper:
- The rubber boots (slides) attached to the bolts lack lubrication and can’t move.
- Torn rubber boots are more susceptible to debris entering them, which results in increased friction.
What causes these issues with the rubber slides?
Usually, when mechanics aren’t careful enough, they can tear the slides when installing new brake pads.
Applying grease and brake cleaner to rubber slides may help temporarily, but ideally, you should see a mechanic to have them checked.
2. Seized-Up Slider Pins
The caliper slide pin allows the caliper to engage and release freely. Each slide pin is covered by a small protective boot designed to stop water and debris from entering.
When this protective boot wears out, debris or water can enter the slide pin bore, resulting in corrosion and friction between the bore and the caliper slide pin.
In extreme cases, the pins can seize up completely, causing the caliper to get stuck.
3. Seized-Up Brake Caliper Piston
Brake caliper pistons allow the brake pad to come into contact with the brake rotor. When the brakes are applied, brake fluid is sent to the caliper, causing the pistons to engage the brake pads.
When the brake caliper piston’s protective rubber boot gets torn, debris can accumulate in the caliper. The piston struggles to slide smoothly, causing the brake caliper to stick.
Why does the rubber boot get torn?
This often occurs when the piston is retracted back to the brake caliper during brake pad replacement.
You can avoid this sticky caliper situation by getting your replacement done by a professional mechanic.
4. Brake Line Obstruction or a Faulty Brake Hose
Why does brake hose damage cause the brake caliper to stick?
Fluid converts the force of the brake pedal into hydraulic pressure, which is applied to the brakes. If the fluid can’t escape to the master cylinder, the pressure on the brake remains.
5. Debris and Stuck Brake Pad Shims
As mentioned previously, debris and brake dust accumulation in various parts of the brakes often cause brake calipers to stick.
This is also the case with brake pad shims.
What are brake pad shims?
Brake shims are essentially a barrier between the brake pad and the caliper. They absorb vibrations and reduce noise.
When debris or brake dust accumulates in the spaces between the brake pad shims and the brake caliper or if they get caught, the brake pads cannot move in and out properly.
6. Parking brake Issues
If your car has a brake disc in each rear brake, then the parking brake can also cause a rear caliper to stick.
If the parking brake gets stuck, the rear brake disc will remain engaged. This can happen due to cold weather (causing the mechanism to freeze), rust, or corrosion.
Sometimes applying grease to the parking brake system can help unstick the rear brake. But you may also need a mechanic to take a look.
Now you know what causes a sticking brake caliper.
But what can you expect if it happens to your brakes?
What Are the Symptoms of a Sticking Brake Caliper?
There are several symptoms you may notice if you have a sticking brake caliper.
Let’s take a look:
1. Car Pulling to One Side
One significant indicator that your caliper is stuck is if your car pulls to one side.
An engaged brake pad means one wheel turns slower than the others, which will apply a rotational force to the vehicle.
2. Abnormal Noise
Because the brake pad is still engaged, it constantly rubs against the brake rotor. This results in fast and atypical wear on the brake pads.
Grinding or scraping noises, especially when they come from one wheel, are often a sign of abnormal brake pad wear caused by a sticking caliper.
3. Smoke or Burning Odor
When the brake caliper is stuck, excess heat is produced by friction between the brake pads and the rotor. As a result, you may notice smoke or a burning odor rising from the affected wheel.
Warning: This excessive heat can also lead to brake fade, which is very dangerous.
4. Car Unexpectedly Slowing Down
The constant contact between a brake rotor and the brake pads can make the car feel like it’s slowing down. This happens regardless of whether or not you have applied the brake pedal.
5. Steering Wheel Vibrations
The excessive heat between the brake pads and the rotor can cause a rotor to become warped (abnormally bent). In cases of excessive heat, you also need to worry about brake fade.
When brake pads come in contact with an extremely warped rotor surface, the rubbing can cause your steering wheel to vibrate.
6. Reduced Fuel Economy
More friction from the sticky brake means more energy is required to turn the wheels. Essentially, your engine needs to work harder to turn the wheels, so it will use more fuel in the process.
While it’s important to know about the causes and symptoms of a stuck brake caliper, you must also know how to diagnose and fix it.
How to Diagnose and Fix a Stuck Caliper?
To begin diagnosing a stuck caliper, you need to locate the wheel where the caliper is sticking.
To do this, take note of:
- The heat of each wheel’s caliper: If one wheel’s caliper is considerably hotter than the others, you’ve likely found the problem area.
- Whether your car pulls to one side: This is usually a sign that the sticking caliper is in the front.
While these methods may point you in the right direction, the best way to diagnose a caliper is to investigate each caliper after removing the wheel and the caliper bracket.
Note: If you’re not confident removing the caliper bracket and inspecting the brake system yourself, it’s best to have a mechanic do the job for you.
A mechanic will look for the following signs of a stuck caliper:
- The slider pins aren’t moving freely
- There are discrepancies between the wear of the inner and outer brake pads
- The piston or piston bolt is damaged
In some cases, applying brake cleaner and brake grease to the problem area may fix a stuck caliper. But in most cases, the caliper must be rebuilt or replaced.
Still curious about sticking brake calipers?
Have a glance at some of the most frequently asked questions below.
4 FAQs About Sticking Brake Calipers
Here are answers to some important questions asked about sticking brake calipers:
1. Is Driving With a Stuck Caliper Safe?
It’s not advisable to drive with a stuck caliper.
Driving with a stuck caliper is not only unsafe, but it can cause significant damage to the brake rotor and compromise your road safety.
If you are experiencing caliper sticking, have your brake system checked by a mechanic.
2. How Can I Prevent a Brake Caliper from Sticking?
There are two ways to ensure your brake calipers don’t stick:
- Replace your brake pads regularly
- Ensure your brake fluid is always filled up
- Have your brake pads, guide pins, and each caliper piston cleaned regularly
Also note the different parts of the brake system (guide pins, brake pads, etc.) have different recommended service periods.
3. How Much Does It Cost to Fix a Seized Brake Caliper?
To fix or replace your brake calipers, you can expect to pay between $100-$2100. The cost involved will depend on:
- How many calipers need fixing or replacing
- The cost of labor
- The make and model of your car
4. Should I Replace or Rebuild My Brake Caliper?
Rebuilding the brake caliper is a more affordable option. But it is likely that over time, the caliper will stick again, especially if the cause is the piston or slider pins.
While there are caliper rebuild kits available on the market, they are mainly for fixing smaller issues to lengthen the life of the caliper.
In the long run, you’ll likely need to replace your caliper if there are any major issues.
Sticking brake calipers are a nuisance. Driving with a sticky brake caliper can cause undue damage to your vehicle and even endanger your life on the road.
If you think one of your brake calipers is sticking, contact AutoNation Mobile Service!
AutoNation Mobile Service is a mobile mechanic service that comes to you to diagnose and fix your car troubles.
Here’s why you should choose us:
- Our mobile car repair and maintenance services are available seven days a week
- We offer upfront pricing and a 12-month | 12,000-mile warranty on all repairs
- We offer convenient online booking
Fill out this form to get an estimate for your brake caliper replacement.