(Updated on October 21, 2020)
Brake calipers are important components of the braking system. Brake calipers clamp the brake pads down against the brake rotors. Once pressure is applied, friction and adhesive forces convert the kinetic energy of the spinning rotor into thermal energy, slowing down the vehicle.
A vehicle would not be able to stop quickly at all without a functioning brake caliper. On vehicles with disc brakes on all four corners, each wheel has a caliper and rotor behind it. The brake rotors are mounted on each wheel hub, so they spin with the wheels.
When you want to slow down your vehicle, you press on the brake pedal which causes the brake calipers and its brake pads to produce friction along with the rotors.
A few vehicles are sold with drum brakes in the rear, even today. Those vehicles only have brake calipers on the front wheels.
It is very rare that you will have a brake caliper sticking, but it does happen. If it is happening to your vehicle, it is important that you understand the symptoms to look out for and their probable causes. That way, you can take your vehicle to the nearest mechanic and have them fix or replace your brake caliper right away (or do it yourself).
Common Sticking Brake Caliper Symptoms
Below are seven of the most common symptoms of brake caliper stickiness.
1) Car Pulling to the Side
This is one of the most common symptoms of a sticky brake caliper. If you notice your vehicle pulling too far to the right or too far to the left, then replace your brake caliper immediately.
2) Brake Pedal Stays Down
Another common symptom of brake caliper sticking is when the brake pedal stays down after you’ve taken your foot off it. The brake pedal will eventually come back up but it will likely take a few seconds.
3) Brake Fluid Leakage
One easy symptom to lookout for is when you have brake fluid leaking from your vehicle. If you check under your vehicle, around your wheels, or notice a trail of fluid coming out as you’re slowing down on the road, then you could possibly have a leak causing your brake caliper to stick.
4) Hard to Stop Vehicle
The brake caliper depends on the proper amount of brake fluid pressure to slow the vehicle down. If you have brake fluid that is leaking from your vehicle, then it will be hard to stop the vehicle. Furthermore, it will make the brake caliper sticky as well.
5) High Pitched Sounds
You will notice problems with the brake caliper right away when you start hearing these high-pitched sounds occurring while applying pressure to the brake pedal. This could mean the caliper is sticking or some other caliper problem too.
6) Difficulty Steering
If one of the front calipers is stuck closed, you may notice the vehicle start to pull to one side.
If one of the front calipers is stuck open, you may notice the vehicle pull strongly to one side under braking. This is because only one of the front brakes is working to slow the vehicle. The front brakes do the vast majority of the braking on most vehicles.
7) Burning Smell
If you notice smoking or an acrid burning smell coming from one wheel, you might want to check on the brakes. When a brake caliper gets stuck in a clamped position, it generates an excessive amount of heat.
This heat will melt the brake pads and heat up one wheel more than the others. In extreme cases, this may even start a fire. The rotor will often have a bluish tint to it once it’s been overheated.
If you’ve overheated your brakes, it’s a good idea to replace the rotors, the brake pads, and flush the brake fluid. Once braking components take on more heat than they were designed to, they will be less effective at stopping your vehicle.
Common Causes of Sticky Brake Calipers
Here are the top causes of a brake caliper sticking.
1) Caliper Slides
The caliper has grooves which secure the brake pads in place and allow the pads to slide inward after you put your foot on the brake pedal.
However, there are shims on the brake pads which can get caught in these grooves from built up debris that may be there. This will make the brake pads unable to slide, causing caliper sticking.
2) Caliper Bolts
There are slides on the brake caliper bolts which must always be lubricated. Each bolt has a rubber boot which maintains their lubrication. If this rubber is torn, it could lead to less lubrication and soon cause stickiness with the brake caliper.
3) Brake Hose
Brake hoses eventually get worn out and then break apart inside. This will direct the brake fluid to possibly flow one way only after you apply pressure to the brake pedal.
If that happens, the fluid can’t get back into the master cylinder after you take your foot off the brake pedal. The result is brake caliper stickiness.
4) Caliper Piston
A caliper piston that doesn’t fit right in the caliper housing could cause the piston to bind under braking or with the release of the brake pedal.
This is more likely to happen on a lower quality remanufactured caliper, but any caliper assembly could have a defect.
5) Brake Pads
If you don’t replace your brake pads soon enough, they are going to get worn out. Then your caliper won’t be able to create the necessary friction against the rotor, causing extreme stickiness in the caliper.
6) Torn Piston Boot
Wheels, tires, and brakes are some of the dirtiest parts of your vehicle. If the caliper piston boot is torn, dirt, dust, and debris may sneak past the boot and into the piston housing.
This debris will then rub against the piston and its housing, causing excessive wear on the internal components of the caliper. Eventually, this may interfere with the piston’s movement. The piston could even seize in the housing.
If the caliper piston or slide pins corrode, they may get stuck in one position. This is more likely to happen in areas that are already prone to rust, such as those that salt their roads in the winter.
What Does it Cost to Fix a Stuck Brake Caliper?
The cost of a stuck brake caliper will vary by vehicle. Replacement cost may be as low as $200 if you are doing the work yourself, but could creep up around $1,000 for more expensive components on larger vehicles.
Bigger brake calipers, rotors, and pads will cost more. It’s a good idea to replace the brake caliper, rotor, and pads all at the same time if you’ve overheated the brakes excessively. Defer to a trusted mechanic for your particular situation.
Some brake calipers can easily be rebuilt, saving you a bit of money if you or your mechanic buy a rebuild kit.
If you’re not doing a caliper rebuild and the brake hose isn’t the root cause of the issue, you will probably have to replace the caliper. Remanufactured calipers are calipers that have been rebuilt by someone else. These units cost less than OEM parts and may suit you just fine, depending on the condition and quality of the rebuild.