How long do brake rotors last?
Over the past 20 years, disc brake systems have become the predominant method of breaking on passenger cars in North America. One of the main components of a disc brake system is the rotor, a durable steel disk that is sandwiched between the brake pads.
Rotors aren’t changed as often as brake pads, in most cases, and it adds between $80 and $400 for a new pair of rotors on a brake job. Read on to learn about your rotors, how long they will last, and how to diagnose whether they need to be changed. The first question you have might be what is a rotor on a car?
What Is a Brake Rotor?
Brake rotors on most vehicles are about the size of a dinner plate and made out of steel. They are bolted to the wheel hub and the brake caliper sits over top of them, with a pair of brake pads seated on either side of the rotor in the caliper.
When you press the brake in your car you force the master brake cylinder to compress brake fluid into the brake caliper and that pressure pushes the brake pads together using the pistons in the caliper. The friction between the brake pads, which wear down over time, pressing against the steel brake rotor causes the rotor to slow down and eventually stop the vehicle.
How Long Do Rotors Last?
The whole system is designed so that the brake pads endure the bulk of the punishment during stopping procedures. Eventually, though, the friction on the brake rotors that comes from the breaking process can wear out the steel, reducing the rotors’ ability to resist warping. Drivers who are very gentle on the brakes and do a lot of highway driving can often have rotors that last for 60,000 miles, but city driving, and especially stop and start or jackrabbit driving, punishes the brakes and can lead to warping as early as 20,000 miles.
Newer vehicles also tend to have thinner rotors from the factory, since rotors are made out of steel and can be very heavy, and manufacturers are working hard to reduce the weight in their vehicles and improve fuel economy. This means that newer rotors will tend to have less resistance to warping and will tend to wear out faster.
When Should You Replace Your Brake Rotors?
How can you tell when to replace rotors? There are some signs of bad rotors that you can look out for, including:
- Pulsing in the brakes. If you notice a pulsing sensation in the brakes when you are undergoing breaking in your car, that may be a sign that you have a warped rotor.
- Very heavy grooves or damage to the rotor. Removing your vehicle’s wheels will allow you to do a visual inspection of the rotors and other brake components. If you notice that there are deep grooves, scoring, or cracks in the rotor, that will quickly cause damage to brake pads, even brand-new brake pads. You should do a brake rotor and pad change in this situation.
- Grinding noises or feelings when braking. If you can feel or hear grinding noises when you are braking, that is also a signal that you have potential issues with your brake rotors and you should do a visual inspection.
- Longer braking distances or inconsistent braking. A worn-out set of rotors can cause your breaking distances to lengthen, which it’s a safety issue that should be dealt with immediately.
It’s important to note that when you do a brake rotor replacement, you should also replace all of the brake pads associated with that rotor. Replacing a rotor without replacing the brake pads can lead to premature damage to the rotor and brake pads are not expensive to replace, so it makes sense to replace them at the same time.
Always replace rotors and brake pads on both sides of the vehicle at the same time, so do all the front brakes or all the rear brakes together. For instance, if you replace only the passenger front rotors and brake pads, you may experience inconsistent and dangerous braking.
What is an Air Brake Rotor, and How do You Replace them?
Passenger cars and light trucks typically use hydraulic brake systems, but larger commercial vehicles and especially heavy-duty trucks tend to have air brakes. One of the differences between hydraulic brakes and air brakes is that the rotor and caliper in an air brake system will be further inboard on the axle of the vehicle than the corresponding rotor and caliper in a hydraulic brake system. The mechanism of calipers and brake pads acting to create friction with the rotor is similar in both systems.
Replacing an air brake rotor requires the mechanic to remove the wheel, ABS sensor, and head unit from the spindle on the axle. Once the head unit is free, loosen the bolts connecting the head unit and the rotor and when reinstalling the new rotor, be sure to use new, clean bolts and torque them to manufacturer specifications.
Can I Replace the Rotors on My Car?
Replacing a rotor only adds a small amount of time to the average brake job on a car. You can get new replacement brake rotors at AutoZone, where the finest brands of OEM and aftermarket parts are available for every vehicle.
FAQ
When you notice signs of warping or damage to the rotors.
Pulsing in the brake pedal, or visible grooves, scoring or cracking on the rotor.
A set of brake pads can last 30,000 to 70,000 miles, but it depends on your driving style and the environment you are driving in. Rotors will usually last longer than brake pads, but it can be good preventative medicine for your vehicle to change them at the same time.
Yes, but your style of driving and environmental conditions will impact how long they last. Repetitive panic stops can do damage to rotors.
Yes, but check the brake rotors to ensure they are still in excellent shape when you change your pads.
