Brake Rotor

Brake rotors are among the most durable parts in your car. However, over time, due to the stress of daily driving, brake rotors wear out. Learn the different types of brake discs and rotors here.

What Is a Brake Rotor?

One question that crops up often among drivers is "What is a brake rotor?" Most people know the basic parts of the car--the brakes, the gas pedal, the hood--but not the nitty-gritty. On most modern car designs, the front and rear brakes are made up of multiple parts: a rotor and a pad. The rotors are circular discs connected to each wheel. They are designed to convert kinetic energy from the turning motion into thermal energy.

How Does a Brake Disc Work?

The pad tightens on the rotor when you press on the brake pedal. Pressure is subsequently exerted on the fluid in the master cylinder, which activates the caliper housing in both pads. The result is friction, which transforms the forward momentum of the vehicle into heat. The heat produced is dispersed from the rotor and pad to the air around the wheel, slowing down the rotation of the wheels and the car’s movement.

Types of Brake Discs

Since the brakes are among the crucial systems in a vehicle, they require special care. The care includes understanding the components of the braking system and the various types of brake discs. These types have changed over time as a result of changing vehicle sizes, weights, and models. Here are the various types of brake discs.

A flat brake disc is the basic brake disc. The disc is flat, smooth, made from iron, and fixed to the rotating axle spindle. It is mostly used for smaller vehicles due to their low weight. The discs are affordable to replace.

A vented brake disc is made with a vented design to dissipate the excess heat produced when braking. The disc is used for vehicles with too much load. When braking, the pad produces a lot of friction, and as the heat increases, the disc needs to vent away the heat to prevent damage on the wheel. The disc has gaps that help in releasing the extra heat.

Drilled rotors have holes that help heat dissipate to keep the discs cool. Drilled discs provide an escape route for waste, heat, and gasses. Additionally, because they have holes, there's less material, making them lighter. However, they tend to need to be replaced more frequently.

Signs Your Brake Disc is in Bad Shape

If you notice the following signs, make an effort to replace your discs:
- Squealing noise when braking
- Warning light on the dashboard
- Your car pulls to one side
- The car vibrates as you brake
- A visual check indicates something wrong with the brakes

When to Replace Your Brake Disc

There is no interval for replacing your brake discs since the duration depends on your car and your driving style. Your car’s brake discs can last up to nearly 50,000 miles. However, the duration can be as low as about 20,000 miles. Your driving style, brake quality, and environment can make your brakes last longer.

How to Change Your Brake Discs

Whether you’re looking to replace your stock quality rotors, or you want to boost your brake system’s power, AutoZone has all the parts you need to do-it-yourself and save on your brake rotor replacement cost. If you've never changed rotors before, check out our DIY brake job guide.

Restore your vehicle’s braking power with new rotors from AutoZone. Whether you need BMW 650i brake rotors, or rotors for any other major vehicle, we have the rotors you are looking for. If you need something like a brake rotor tool or any other tools or parts for your job, we have that too. Our wide selection of auto parts and our Loan-A-Tool program make changing your own brake rotors easier than ever. Your local AutoZone has everything you need to do the job right.