NuBrakes Blog What are Brake Calipers, and Signs of Potential Failure Image

What are Brake Calipers, and Signs of Potential Failure

What are Brake Calipers?

Brake calipers house your car’s brake pads and pistons and squeeze the brake pads against the rotor to stop the car. The calipers support the brake pads on both sides of the rotor while using pistons to convert the pressure from the master cylinder into pressure from the brake pads to the brake rotor. Caliper size varies according to the car.

Key Takeaways:

  • Brake calipers are essential to a car's braking system, housing brake pads and pistons and squeezing the brake pads against the rotor to stop the car. They come in two main types: floating and fixed calipers.

  • Brake caliper failure can lead to reduced braking force or a complete loss of brake function. Regular inspection and maintenance are necessary to ensure proper functioning and safety.

  • Warning signs of potential brake caliper failure include the car pulling to one side when braking, uneven brake pad wear, leaking brake fluid, excessive brake dust, and unusual sounds when braking.

  • When replacing brake calipers, it's recommended to replace them in pairs to maintain balanced braking performance. Trust a certified mechanic or a trusted auto repair shop for brake caliper replacement.

How do Brake Calipers Work?

When a driver presses the brake pedal, it generates hydraulic pressure in the master cylinder, which is then transferred to the brake caliper through the brake lines. The brake caliper is usually mounted on a bracket, and its primary function is to create the clamping force necessary to press the brake pad against the brake rotor on either side. Inside the brake caliper is a piston, which is activated by the pressure from the master cylinder.

This piston pushes the brake pad onto the brake rotor, generating friction that slows down the car. The caliper piston is sealed and protected by a rubber boot to prevent dirt and grime from entering the system and causing it to fail.

Crucial to the caliper's functionality, the piston and pin move in unison to apply balanced pressure on the brake rotor. When brake calipers fail, they can lead to a reduced braking force or even a complete loss of brake function, making regular inspection and maintenance of this critical part essential.

Types Of Calipers

There are two main types of calipers:

Floating calipers

These components move in and out according to the motor and have only one or two pistons on each side of the rotor. The pistons push the entire caliper when the brake is applied, creating friction from the brake pads on the sides of the rotor.

Fixed calipers 

As the name implies, fixed calipers do not move but instead have a set location arranged on the opposing sides of the rotor. The pistons apply force from both sides of the caliper and are preferred for their high performance, but they are more expensive than floating calipers.


While brake pads and rotors are frequently damaged, calipers do not need to be replaced often. The primary reason for worn-out calipers is due to driving an automobile on worn-out pads or twisted rotors. This can hinder the system's ability to dissipate frictional heat, leading to wear and degradation.

As a result, if a brake pad cannot shield the caliper from excessive heat and the piston is wrecked, heat can reach the brake fluid, degrading its quality and potentially resulting in brake failure. Moreover, torn-out or degraded pistons can stick in a single position, applying a constant brake to the wheels until the problem is resolved.

Signs of Potential Brake Caliper Failure

Before a brake caliper fails, there are often warning signs that can provide a clue that they need to be checked, repaired, or replaced:

  • When the brakes are engaged and running, a retracted piston can cause the automobile to pull toward the side while traveling toward the engaged brake, negatively influencing braking distance.

  • If a brake pad erodes quickly, it may be the result of a clogged caliper. In these circumstances, the calipers generate excessive heat, which increases the wear on the brake pads. Without immediate servicing or maintenance, this clogging can lead to caliper failure.

  • A braking fluid leak can be the result of a broken piston. If there is a leak, a warning light appears on the dashboard which means the brakes should be inspected by a professional.

  • When inspecting brake pads during routine maintenance, evaluate the wear by comparing both sides of the rotor or by contrasting one wheel against another. If there is uneven wear, the calipers may require servicing.

  • A cloud of brake dust or excessive brake dust may mean you have a seized caliper. If the piston is locked onto the brake pad, it may feel as though the brake is compressed while driving or may even prevent the vehicle from moving at all.

  • A high-pitched squeal when braking can mean trouble, as this could be from your brake calipers indicating a defective or frozen part. Taking your vehicle to a repair shop is essential because further damage can cause the brakes to lock completely.

  • Hearing a clunking sound when engaging the brakes can mean the brackets that hold calipers in place may be broken or otherwise defective. This is not a common problem, but if this happens, do not drive the vehicle because the brakes could lock up entirely.

Ignoring any of the above signs could lead to potential dangers to your vehicle which can prove costly to repair. It is important to identify any problems quickly to prevent more serious destruction.

Nubrakes - Oil Change Discount.webp

Frequently Asked Questions about Brake Calipers

How do brake calipers connect with the other components in the braking system?

To understand the connection between brake calipers and the entire braking system, it's important to have a basic knowledge of the system's components. The braking assembly comprises several elements, including the master cylinder, brake conduits, valves, and brake calipers.

The master cylinder is entrusted with generating adequate force to propel the brake fluid via the brake channels and into the calipers. Positioned near each wheel, calipers are the linchpin in decelerating or halting a vehicle. Encased within the brake calipers is a piston, which is actuated by the pressure exerted by the brake fluid.

As the driver applies force to the brake pedal, a cascade of events culminates in the piston pressing against the brake pad, engendering friction against the wheel and ultimately slowing or ceasing the vehicle's motion. Consequently, the interconnection between brake calipers and the entire braking mechanism is indispensable for the brakes' seamless operation.

Any complications with the master cylinder, brake conduits, or valves can impinge upon the pressure and circulation of brake fluid to the calipers, leading to diminished braking efficacy. This knowledge is of vital importance for individuals seeking insight into their vehicle's braking system functionality.

What causes brake calipers to stick?

Brake calipers may stick due to various reasons. One of the most common causes is rust build-up on the caliper guide pins. Rust can seize up the moving parts of the caliper, making it difficult for them to slide back and forth properly.

Another reason could be the brake pads that have worn down unevenly, causing the caliper to tilt and get stuck. This can result in a reduction of braking power, which can make it more challenging to stop a vehicle quickly.

The brake fluid may also be a factor if it has become contaminated with dirt or moisture, which can cause corrosion inside the caliper, leading to a sticky piston.

Lastly, in some cases, the caliper itself may simply be worn out or damaged, causing it to malfunction when brakes are applied. Regular brake inspections and maintenance can help prevent these issues, but prompt repairs are necessary if a problem arises. 

Which brake calipers are the best?

When it comes to brake calipers, the debate rages on as to which type is the best. Ultimately, the choice between fixed and floating calipers comes from personal preference and specific driving needs.

Fixed calipers generally provide greater stopping force and responsiveness, making them a better choice for high-performance racing vehicles.

Floating calipers, on the other hand, are more commonly found on everyday vehicles and offer a simpler design and lower cost. In recent years, many manufacturers have also begun producing ceramic calipers, which offer superior heat resistance and durability.

Ultimately, the best calipers for your vehicle will depend on your driving type and the quality of the materials used in the manufacturing process. Regardless of the type of caliper you choose, regular maintenance and inspection are necessary to ensure the longevity and safety of your vehicle's braking system. 

Should brake calipers be replaced in pairs?

When one brake caliper fails or wears out, whether to replace it alone or in pairs arises. The general consensus among car manufacturers and mechanics is that replacing brake calipers in pairs is best for several reasons. 

First, replacing both calipers ensures that they have matching levels of wear, preventing uneven braking performance.

Second, replacing one brake caliper and leaving the other old one can create an imbalanced brake system that affects the vehicle's handling and safety.

Finally, replacing both calipers simultaneously saves time and money in the long run, as the labor cost of replacing one caliper is nearly identical to replacing two. Therefore, replacing brake calipers in pairs is recommended to maintain safe and proper braking performance. 

Where can I buy brake calipers for my car?

You can buy brake calipers for your car at auto parts stores, online retailers, and car dealerships. Some popular options include AutoZone, O'Reilly Auto Parts, Buy Brakes, Walmart, Amazon, and eBay. Make sure to check the compatibility of the brake calipers with your car's make and model before purchasing.

Who should I trust for Brake Caliper Replacement?

It is recommended to trust a certified mechanic or a trusted auto repair shop for brake caliper replacement. Look for professionals who have experience and knowledge in the specific make and model of your vehicle. Additionally, consider their reputation, customer reviews, and accreditation before deciding. 

Final Thoughts

If faced with any signs that the brake calipers are worn or failing, you should seek professional consultation immediately as failed brakes can lead to severe wreckage, injury, or even death.

Fortunately, NuBrakes offers its clients a wide range of services, including brake inspection and servicing. Our brake repair services are performed by highly certified and professional specialists with extensive expertise in car brake repair. Contact us today to experience our top-of-the-line customer service and transparent repair procedures.


Brake problems? Schedule a free brake repair estimate now.

More Brake Posts

Schedule A Brake Repair Or Get a Quote Now.