Bad Brake Calipers in Cars: Symptoms, Causes & More
What Are Brake Calipers?
Brake calipers are a key component of the braking system in vehicles with disc brakes. They hold the brake pads in place and squeeze them against the brake rotor to create friction and slow the wheels down. According to How Brake Calipers Work, brake calipers are “hydraulically operated mechanical devices designed to transmit hydraulic pressure into clamping force on brake pads and enable slowing and stopping of the vehicle”
When the brakes are applied, brake fluid from the master cylinder creates hydraulic pressure in the brake lines and brake caliper pistons. This pressure pushes the caliper pistons outwards, pressing the brake pads against the rotor surface to slow its rotation and the wheel speed. The caliper slides allow the caliper assembly to move so that the pads make proper contact with the rotor.
Most vehicles today use floating calipers, where the caliper housing is fixed and only one piston applies pressure to the inner brake pad. The caliper then slides along support mounts so the outer brake pad contacts the rotor as well. This enables even pressure and wear on both pads (How Brake Calipers Work, 2022). Properly functioning brake calipers are essential for effective, balanced braking power.
Symptoms of Bad Brake Calipers
There are several noticeable symptoms that can indicate your brake calipers are failing and need to be repaired or replaced. Some of the most common symptoms of bad brake calipers include:
Uneven braking – If one brake caliper isn’t functioning properly, it can cause the vehicle to pull to one side when the brakes are applied. This uneven braking effect is a telltale sign of a bad caliper.
Pulling to one side when braking – Related to uneven braking, if your car pulls to the left or right when you hit the brakes, it likely indicates an issue with a stuck or seized caliper. This symptom typically becomes worse the harder you brake.
Grinding noises – You may hear grinding, scraping or squealing noises from the wheel area when braking if the brake pads are badly worn or the caliper is sticking. This metal-on-metal sound signifies advanced damage.
Brake pulsation – A consistent pulse or vibration in the brake pedal can be caused by a caliper not retracting properly. This symptom is very noticeable when braking at higher speeds.
Brake fluid leak – A leak of brake fluid around the caliper seal indicates damage allowing fluid to escape. Check around the wheels and under the vehicle for signs of leaking fluid.
Loose pedal feel – A soft, spongy brake pedal can result from air in the hydraulic system caused by a fluid leak from a bad caliper seal. This will reduce braking power and pedal firmness.
Causes of Bad Brake Calipers
There are several common causes of brake caliper failure or malfunction:
- Worn out brake pads – Brake pads pressed against the rotor create friction and heat. Over time, the brake pads wear down and need to be replaced. If ignored, the pads will completely wear away, causing the caliper piston to directly press against the rotor, leading to damage.
- Stuck or seized brake caliper pistons – The pistons inside the brake caliper push the pads against the rotor. If dirt, rust or brake fluid contamination gets in, the pistons can stick and stop sliding properly. This will prevent the brakes from releasing fully.
- Worn or damaged slider pins/bushings – Slider pins allow the brake caliper housing to slide as the brake pads wear down. If the slider pins get corroded or the rubber bushings wear out, the caliper can stick and not float properly.
- Corroded brake caliper – Exposure to water, salt and other elements can cause the brake caliper assembly to rust and corrode over time. This can lead to sticking pistons, slider pin issues and brake fluid leaks.
- Brake fluid issues – Contaminated or improper brake fluid can cause seals to deteriorate, leading to leaks and caliper damage. Lack of brake fluid due to leaks will also prevent proper brake operation.
According to Burt Brothers, other signs of a bad brake caliper include noisy braking from worn pads grinding against the rotor, uneven pad wear, brake pulsation, and one hot wheel from a caliper not releasing properly (1). Keeping brake pads and fluid fresh, and watching for leaks and stuck components can help avoid brake caliper failure.
(1) https://burtbrothers.com/tips/signs-you-may-have-a-bad-brake-caliper/
How to Diagnose Bad Brake Calipers
There are several methods you can use to diagnose a bad brake caliper:
Visual Inspection
First, visually inspect the brake caliper, brake pads, and brake rotors for signs of damage or uneven wear. Look for brake fluid leaks around the caliper seal. Also check for corroded or stuck caliper pins that can prevent the caliper from operating smoothly (source: https://www.carparts.com/blog/how-to-diagnose-a-faulty-brake-caliper/).
Uneven Pad Wear
Inspect the brake pads on both sides of the caliper. If one pad is significantly more worn than the other, this can indicate a caliper issue. A sticking caliper piston will cause uneven brake pad wear (source: https://www.autozone.com/diy/brakes/bad-brake-caliper-symptoms).
Brake Pedal Inspection
Pay attention to any changes in brake pedal feel or unusual sounds when braking. A bad caliper can cause the brake pedal to pulse or vibrate. You may also hear grinding or squealing noises from a caliper not retracting properly.
Wheel Speed Sensor Test
Use a diagnostic scan tool to compare data from the wheel speed sensors. A big difference between two wheels indicates a caliper may be sticking and slowing one wheel.
Dangers of Driving with Bad Brake Calipers
Driving with faulty or seized brake calipers can be extremely dangerous and should be avoided. Here are some of the main risks:
Uneven braking – With one brake caliper not functioning properly, only one side of the brake rotors and pads will engage when the brakes are applied. This leads to uneven braking forces on each wheel, which can make the vehicle pull to one side when braking and result in loss of control.
Brake failure – If the caliper seizes completely, the brake pads on that wheel will not engage at all when the brakes are pressed. This effectively eliminates braking ability on that entire wheel, significantly reducing overall stopping power. Complete brake failure can occur if multiple calipers fail.
Increased stopping distance – Due to uneven braking forces and reduced braking power, vehicles with bad brake calipers require longer stopping distances. This makes it harder to slow down in time to avoid hazards or come to a complete stop.
Accident risk – The uneven braking, pulling, and increased stopping distance caused by faulty brake calipers can easily result in loss of control and accidents. Statistics show brake defects play a role in a large percentage of crashes each year. Severe brake caliper issues at high speeds can be catastrophic.
“Driving with a seized or stuck brake caliper is extremely unsafe and can lead to complete brake failure, which often results in serious accidents” according to this source. It’s critical to have brake caliper issues addressed promptly by a professional mechanic.
When to Replace Brake Calipers
Brake calipers should be replaced if they are seized, leaking brake fluid, badly corroded, or have damaged piston seals. A seized caliper will cause the brake pads to constantly rub against the rotor, leading to uneven brake pad wear, overheating of the pads and rotor, and a loss of braking power. Leaking brake fluid is a hazard and will lead to complete brake failure over time as fluid is lost. Bad corrosion can cause components like the caliper pistons and slider pins to get stuck, resulting in uneven pad wear, pulling to one side when braking, and other issues. Worn piston seals will allow fluid and air to leak by, leading to spongy brake pedal feel, brake fade, and poor brake performance.
According to mechanics on Stack Exchange, brake calipers should be replaced once they get to the point where cleaning and lubricating slider pins and changing rubber components no longer restores proper operation (https://mechanics.stackexchange.com/questions/11249/at-what-point-do-you-need-to-replace-the-calipers). If a caliper is leaking, not retracting properly, or seized, replacement is required.
Brake Caliper Replacement Cost
The cost to replace brake calipers varies depending on the make, model, and year of the vehicle. The main factors affecting brake caliper replacement cost are:
- Parts – The brake calipers themselves can range from $50-$350 per caliper for aftermarket parts, while OEM parts typically cost $100-$500 per caliper (HeartAutoCare).
- Labor – Labor costs typically add $100-$150 per caliper (RepairPal), with most vehicles having 2-4 calipers.
- Location – Repair costs are often higher in areas with a higher cost of living.
On average, you can expect to pay the following brake caliper replacement costs:
- $100-$500 per caliper for parts
- $100-$150 per caliper for labor
- Total of $300-$1000 per caliper replacement when accounting for both parts and labor (HeartAutoCare).
For a basic brake caliper replacement on a typical passenger vehicle, you’ll usually pay around $600-$1200 if replacing 2-4 calipers. High-end vehicles can cost even more. Getting OEM parts or premium brake calipers increases the parts costs substantially compared to aftermarket.
Preventing Brake Caliper Failure
There are several things you can do to prevent brake caliper failure and extend the life of your calipers:
Perform regular brake inspections – Get your brakes inspected at every oil change or at least twice a year. This allows any potential issues to be caught early before they lead to bigger problems.
Change brake fluid regularly – Brake fluid absorbs moisture over time which can cause corrosion and sticking pistons. Flushing the brake fluid every 2 years helps keep things operating smoothly. (https://nubrakes.com/blog/brake-calipers/)
Lubricate slider pins and caliper bolts – These moving parts can rust and seize up if not lubricated regularly. Use brake caliper grease on the pins and anti-seize compound on the bolts.
Replace worn brake parts promptly – If you notice any issues like worn brake pads, leaking fluid, stuck pistons, etc., have them repaired right away. Left unaddressed, these problems will lead to caliper failure.
Taking care of your brake system with regular maintenance and prompt repairs when needed will help your calipers last longer and perform better.
Signs You Need New Brake Pads
There are several telltale signs that indicate your brake pads need replacing. Three key symptoms to watch out for include:
Thin brake pad material – brake pads have built-in wear indicators that make a screeching noise when the pad material wears down to a certain thickness. This lets you know it’s time to replace them. As pads wear down, you may also notice more brake dust on your wheels.
Brake squeal – friction between the pad and rotor can cause a high-pitched squealing or screeching noise when braking. This indicates the brake pads are excessively worn and need replacement. According to experts, brake squeal typically starts being audible once pads are worn down to 3/16 inch or less.[1]
Vibration when braking – if you feel shaking or pulsation in the brake pedal when braking, the pads may be unevenly worn. This can lead to rotor warpage and vibration. Replacing the brake pads and resurfacing or replacing rotors will solve the vibration.
Don’t put off brake pad replacement once these symptoms start happening. Worn pads reduce braking effectiveness and can lead to brake failure, posing a serious safety hazard. It’s recommended to inspect pads during every oil change and replace them promptly when worn.
[1] https://www.performancehondastore.com/blog/signs-you-need-new-brake-pads/
When to See a Mechanic
If you notice any of the symptoms of bad brake calipers, the first step is to inspect the brakes yourself or have someone you trust inspect them. Look for issues like worn brake pads, brake fluid leaks, stuck caliper pins, etc. However, if the symptoms persist after inspection, it’s best to take your vehicle to a professional mechanic.
Mechanics have the proper diagnostic tools and expertise to thoroughly inspect your brakes and identify any issues with the calipers or other brake components. They can use devices like scan tools to check for brake-related error codes as well as perform tests like measuring brake pedal reserve to check caliper piston operation.
You should also see a mechanic right away if you lack the proper tools, skills, or ability to replace brake parts like the brake pads or calipers yourself. Brakes are a vital safety component, so it’s best to have a professional mechanic take care of any needed brake repairs unless you’re highly experienced working on brakes.
Don’t delay brake system inspections and repairs. Driving with bad brake calipers can be extremely dangerous. Visit a mechanic as soon as possible if you notice signs of caliper failure.