What Is a Brake Caliper and How Does It Work?

A brake caliper assembly is an important part of the modern disc brake system. It houses the brake pads, caliper piston, and other parts to help create friction that brings your car to a halt. Most cars have disc brakes in the front, but some may also have them as the rear brake. 

To learn how a caliper promotes braking efficiency, let’s see how it works:

• When you apply the brakes, a small piston inside the master cylinder puts pressure on the brake fluid.

• The brake line then carries this pressurized fluid (in the form of hydraulic pressure) to the front and the rear caliper.

• Pistons within the calipers then convert the hydraulic pressure into mechanical force.

• The pistons use this force to push the brake pad against the side of the rotor, resulting in friction that slows down your car.

How to Replace a Faulty Brake Caliper: A General Know-How

To change an old caliper, you need to perform a detailed brake inspection to check the severity of the problem. Moreover, you need mechanical knowledge and car repair experience, as incorrectly replacing this part can impact the overall braking efficiency. 

That’s why this complex brake job is best left to an auto repair mechanic. 

Let’s have a look at the steps they’ll follow:

1. Park the car on a flat surface and engage the parking brake.

2. Elevate the front or rear of the car and secure it using jack stands (based on whether the front or rear brake calipers need replacement).

3. Remove the lug nuts using a wrench, followed by the wheel and tire assembly.

4. Place a pan below the caliper to collect fluid spills and remove the brake hose by loosening the banjo bolt (the hollow bolt that connects the brake hose to the caliper).

5. Insert a rubber seal in the line to minimize brake fluid loss.

6. Check the brake line and hose for wear and replace them if necessary.

7. Unscrew the caliper bolts and remove the old caliper using a screwdriver or a prybar.

8. Remove the brake pad from the caliper bracket if working with fixed calipers (not applicable for floating calipers).

9. Install the brake pad into the new caliper bracket (applicable to a fixed caliper only). In case of uneven brake pad wear, the mechanic will install a new pad.

10. Place and align the new caliper to the brake rotor.

11. Tighten the mounting bolts using a torque wrench and secure the caliper.

12. Fix the brake hose to the caliper using its banjo bolt and tighten it as per torque specifications.

13. Repeat the steps for other worn front and rear calipers.

14. Inspect the braking system for any hydraulic fluid leak and fix it.

15. Perform a complete brake bleed using a vacuum bleeder to ensure there’s no air in the system after the replacement.

16. Check the brake fluid level and refill the master cylinder if required.

17. Reinstall the wheel assembly, remove the jack stands, and lower the vehicle.

18. Drive the vehicle to test the new caliper.

How Much Does a Brake Caliper Replacement Cost?

The average cost of a brake caliper replacement is between $300 to $1,500 per caliper. Some factors that can alter your brake caliper replacement cost include: 

• Vehicle make and model: The disc brakes of cars like Honda and Toyota work fine with a standard new brake caliper. However, luxury vehicles like Mercedes and BMW require specialized brake components, which can increase the part and labor cost.

• Number of calipers: Most auto repair mechanics recommend replacing them in pairs, which increases the cost of parts. Changing a single caliper takes around one to three hours. The longer the duration, the higher your labor cost.

• Caliper type: Calipers come in three types: fixed, floating, and sliding. Floating calipers are the most affordable, while fixed calipers are the costliest.

• Original Equipment Manufacturer (OEM) vs aftermarket brands: You can opt for high-quality aftermarket calipers to reduce your expenses. However, OEM auto parts are more durable.

• Extra brake repair: A stuck caliper piston can cause uneven brake pad wear or damage the rotor (brake disc). To fix these, you’ll need a brake pad replacement or a rotor resurfacing service, which will increase your overall cost. 

7 Looming Signs that Point to a Bad Brake Caliper

A faulty rear or front brake caliper can present itself in many ways. Here are some signs that indicate you need brake caliper repair or replacement: 

1. Brake Warning Light Turns On

Usually, a built-in brake warning light will alert you if there’s any problem with your vehicle’s braking system. However, it’ll be tricky to determine if the problem is with your calipers or another brake component.

If the warning light has been active for a while and you’ve noticed uneven braking performance, contact a professional mechanic for a check. 

2. Squealing, Squeaking, and Grinding Brake Noise

A stuck caliper piston can cause the brake pad to drag against the rotor (brake disc), producing excess brake dust that may stick to the car’s tires, caliper, and brake rotor. This dust accumulation can lead to an uneven rotor surface, which causes squealing, squeaking, or vibrations while braking.

Additionally, if you have a worn brake pad, its metal backing plate can rub against the rotors to create a loud grinding noise. While brake noise may not be a direct symptom of failing calipers, it’s best to get a comprehensive brake inspection and repair service to avoid risks.

3. Burning Smell Due to Overheated Brakes

If the caliper gets stuck due to dirt accumulation, it can continuously push the brake pad against the side of the rotor. 

Eventually, friction and heat build-up between the pad and rotor can cause your vehicle’s braking system to overheat. This emits a burning smell and can damage the system, resulting in a costly car repair service. 

4. Brake Fluid Leak

A broken or faulty caliper piston seal can lead to a brake fluid leak. This leaking fluid can then absorb moisture and cause corrosion of metal brake components such as the calipers and rotors. As the leak continues and the brake fluid levels drop, you’ll find it difficult to decelerate the vehicle. 

5. Vehicle Veers Off to One Side While Driving

A common cause for a vehicle to pull to one side is a failing caliper piston.

If you park your car in the open and don’t drive it often, moisture and corrosion can accumulate in the brake caliper assembly. Gradually, the rusted piston gets stuck and exerts uneven braking pressure, which forces your vehicle to pull to one side. 

6. The Brake Pedal Feels Soft

A soft or spongy brake pedal occurs when you feel little to no resistance in the brakes, and the pedal sinks more than usual when you press it.

Typically, low brake fluid levels and a damaged master cylinder cause this issue. But a faulty brake caliper can also make the pedal spongy.

When the brake rotor and pad rub against each other, it creates heat and friction. This heat can damage the caliper and weaken the brake pressure. Without sufficient pressure, the pedal will feel soft and spongy.  

It’s best to have a trained technician examine your car to determine which brake component is causing this problem.

7. Increased Vibrations While Braking

If the caliper mounting bolts or slide pins weren’t tightened properly in the last brake repair, the caliper may shake erratically. This causes vibrations while you’re driving or applying brakes. 

To resolve this problem, call an expert.

4 Brake Caliper Replacement FAQs

Here are the answers to some common queries on brake calipers that you must know: 

1. Can You Drive with a Bad Brake Caliper?

Technically, you can, but you shouldn’t.

A failing brake caliper won’t create the friction that helps you slow down the car. Once it fails, it can affect the functioning of your disc brake system. 

Slowly, you’ll notice your car pulling to one side or having reduced stopping power, which will make your vehicle extremely unsafe to drive.

A bad caliper can also damage other brake parts, such as the pads and rotors. To restore them, you’ll need a brake pad and rotor replacement. In case of severe damage, you may require a complete brake replacement, which will be costly. 

For your safety, call a trained technician and schedule a brake caliper repair ASAP.

 2. How Often Should You Change a Brake Caliper?

Brake calipers last for about 75,000 to 100,000 miles. Based on your vehicle’s model and driving habits, they may even last 10 years or so.  

However, if you suspect your car has brake caliper issues, ask a professional mechanic for an inspection.

3. How Can You Prolong the Lifespan of a Brake Caliper?

Your calipers can last longer if you: 

• Get the brakes checked every six months or at each oil change to look for a hydraulic fluid leak, worn brake pad, or failing caliper.

• Install new brake pads around 25,000 to 65,000 miles to prevent premature wear of calipers and other system parts.

• Schedule a brake fluid flush every two years or 30,000 miles to remove dirt or moisture that can corrode the caliper and harm the system. 

4. How to Save Money on a Brake Caliper Replacement

Here are some tips to help you save on the replacement service: 

• Compare brake job rates: Compare multiple quotes from dealerships and garages to get the best price for a brake service or replacement.

• Look for discounts or promotions: Several automotive repair shops offer seasonal discounts or special deals on complete brake replacement. This can make it more cost-effective to invest in new brakes rather than just replacing a caliper.

• Purchase brake parts in a bundle: Consider purchasing brake kits that include new brake pads, rotors, and calipers, as they may be sold at a discounted price. This way, you can buy high-quality parts like ceramic brake pads and steel calipers at an economical rate.

• Verify the warranty coverage: Your car insurance may not cover brake caliper replacement, but a comprehensive warranty might. If your warranty is valid, it can significantly reduce your costs on this brake service.