What are brake rotors? | How long do brake rotors last? | How do you know if you need new brake rotors? | Do you have to replace rotors when replacing brake pads? | What are your options for brake pad and rotor replacement? | How much do new brake pads and rotors cost? | What to expect after replacing brake pads and rotors
How often you need to replace your brake rotors in relation to your brake pads depends on a lot of different variables. These include the quality and durability of your original brake components and where, when, and how often you drive your vehicle.
Like with brake pads, there are a lot of different brands and types of rotors out there. Rotor quality ranges from exceptional to questionable, and that will have a lot to do with how often they will need to be replaced alongside brake pads.
Depending on where you live, your car is going to be exposed to different elements resulting in varying levels of corrosion, dirt, or debris. Perhaps you do a lot of driving down gravel roads or live in a harsh climate where the roads are regularly salted to melt ice. Chances are, you’re going to need new rotors sooner than someone with the same vehicle who lives in a mild climate with little exposure to extreme driving conditions.
So, can you replace brake pads without replacing rotors? This guide walks you through the ins and outs of brake rotor replacement, including when it’s time to have them replaced, and how much you can expect it to cost when you do.
What are brake rotors?
Peer through the spokes on your hub cap, and you’ll see a circular disc connected to the wheel. You’ve just encountered your brake rotor.
Rotors work hand and hand with your brake pads to bring your vehicle to a stop. In a standard disc brake system like you find on most conventional vehicles today, brake pads are held in place on either side of the rotor by a caliper. When you step on the brake pedal, it engages the master cylinder and sends a signal to your brake caliper to clamp down on the rotor with the brake pads. As the brake pads squeeze against the large surface of the rotor, the resistance creates friction. This friction slows the rotation of the wheel and eventually brings your vehicle to a halt.
When it comes to rotors, not all of them are made the same way. In fact, there are four different types to choose from. The rotors used on your vehicle will probably differ depending on whether you drive a sedan, pickup truck, or performance vehicle. The four different rotor types are:
- Blank & Smooth. Blank and smooth rotors are what you'll find on most passenger vehicles and feature a smooth, blank metal surface all the way around the rotor
- Drilled. Drilled rotors feature drilled holes around the metal surface
- Slotted. Slotted rotors feature long "slots" or lines in the metal surface
- Drilled & Slotted. Drilled and slotted rotors combine the drilled holes and slots for enhanced performance
How long do brake rotors last?
Made of cast iron mixed with other elements like carbon, graphite, and pearlite, rotors are designed to withstand friction and dissipate the heat. However, just like brake pads, brake rotors wear down a bit every time you apply the brakes.
It used to be that you could rely on original equipment brake rotors to last through two or three brake pad replacements. However, on many newer car models, the rotors are designed to be lighter and thinner to allow for more fuel efficiency. As a result, they can wear out just as quickly as your brake pads (or even faster). While modern brake rotors can usually last anywhere from 20,000 to 70,000 miles, their exact lifespan depends on a few different variables:
- The quality and durability of the rotor
- How efficiently the rotor dissipates heat
- The type of brake pad used
- Driving conditions (i.e. city vs. highway)
- Climate and exposure to elements like road salt
- How aggressively you brake
How do you know if you need new brake rotors?
When you bring your car to a mechanic, they will often inspect your brake system to determine if it needs any repairs. However, in between trips to the mechanic, there are a few warning signs you can look out for.
Grooves or ridges on the surface of the rotor
As a quick test to see if you need new brake rotors, stick your finger through one of the slots in your hub cap (or take it off entirely to get better exposure) and feel along the surface for any deep grooves, which are essentially cracks in your rotor. Then feel along the outer edge to see if there's a ridge. A lip around the edge of the rotor is a sign that your rotor worn fairly thin and it's probably time to have it replaced.
Pulsating or shaking when you stop
A good way to determine whether or not you need new rotors is take your car out for a test drive. Accelerate to about 40 miles per hour and slam on your brakes. Hold the steering wheel tightly and feel for a significant amount of shaking or vibrating coming through your wheel or brake pedal. If your car pulsates when you hit the brakes, it’s a pretty good indication of warped rotors. This happens when your brakes can no longer cool themselves efficiently, and it’s a good idea to have them looked at by a mechanic.
Grinding noise when braking
Grinding brakes indicates that your brake pads have worn all the way down and are now grinding metal on metal against the rotors. The damage can be pretty intense, so you are probably in for a complete new set of pads and rotors.
Corrosive rust on the rotor
When it comes to rotors, not all rust is created equal. Surface rust on rotors is fairly normal and generally falls away after use without impacting stopping power. Corrosive rust, on the other hand, bleeds into the casting and undermines the structural integrity of your rotors. This type of rust often appears when you live under harsher weather conditions where your vehicle is exposed to road salt. It can also occur if you let your car sit too long and allow the surface rust etch into the rotor. Corrosive rust can destroy your brake pads and wreak havoc on your brake performance, so when the rust bugs start to bite, it’s recommended that you get your rotors replaced along with your brake pads.
Thinned out rotors
Rotors come with a specified discard thickness, set by the part manufacturer. This measurement will differ for each rotor. However, it’s usually indicated by a marker right on the brake component. The minimum thickness specification is an important dimension because it is the minimum thickness that provides safe braking. As your rotor wears and thins out, it has less mass to absorb and dissipate the heat generated during braking. Wear also reduces the strength of the rotor, increasing the risk of it cracking or even breaking. As a rule, rotor thickness should be measured approximately every 10,000 miles or whenever you have your brakes serviced.
Other brake symptoms that may not be related to rotors
Additional signs that you need brake service, which may or may not have to do with the rotors, include squeaking or squealing coming from the brakes, a brake system indicator light coming on, veering to one side when braking, or decreased brake performance that results in taking longer to stop. These symptoms might originate with your brake pads, brake fluid, master cylinder, or caliper. If you notice anything out of the ordinary with your brakes, it’s safest to have them checked out by a mechanic as soon as possible.
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Do you have to replace rotors when replacing brake pads?
If you're experiencing brake issues, your mechanic will take a look at both your brake pads and rotors to determine what types of repairs are needed. If your rotors appear warped or worn beyond the recommended discard thickness, they’ll recommend having them replaced along with your brake pads. If your rotors seem okay, some shops will recommend having them resurfaced along with the new pads.
Resurfacing (sometimes referred to as “turning” or “machining”) your rotors involves using a machine called a lathe to shave them down so your new brake pads can rub against a smooth surface. While this can often save you some money, it isn’t always recommended.
Brake rotors come with a minimum discard thickness set by the manufacturer. This measurement determines how thin a rotor can get before it needs to be replaced for performance and safety. When material is removed from the surface of the rotor during machining, the edges can wear away brake pads faster than traditional smooth surfaces. The removed material also decreases the durability of the rotor, making it more prone to cracks and warping.
What are your options for brake pad and rotor replacement?
When it’s time to service your brakes, you typically have three options for brake replacement: replacing just the brake pads, replacing the brake pads and resurfacing the rotors, or replacing the brake pads and rotors together. Each option has its advantages. What you choose should depend on how much life your brake rotors still have in them, your budget, and how quickly you want to end up back at the shop.
Replacing brake pads only
If your rotors aren’t worn or damaged when you go in for brake service, you can probably get away with changing just the brake pads. While this is definitely the most economical option, at least in the short-term, keep in mind that the new pads might not fit perfectly with the older brake rotors, since these components are designed to wear down together. The mismatch of old and new could cause a bit of noise and vibration as the two components (pads and rotors) get used to each other. When fitting new brake pads against old rotors, you also run the risk of uneven wear on the pads, which could result in having to replace them again sooner than you might like.
Replacing brake pads and resurfacing rotors
If there is enough thickness left in your rotors when you go to have your brake pads replaced, some shops will offer to resurface your rotors on a machine (called a lathe) to bring them down to a smooth surface for the new brake pads to wear against. This is often used as a cost-saving mechanism against paying to have them replaced. Shops can charge anywhere from $75 to $120 for rotor resurfacing, about a hundred dollars less than it would be for a full rotor replacement.
While the initial savings are significant, the process of machining rotors takes off layers of their surface and may cause them to warp due to their lessened ability to dissipate heat. While new rotors can last up to 70,000 miles, resurfaced rotors have been known to warp only 10,000-15,000 miles after machining.
Though it isn’t always the case, you could end up back in the shop for new brakes only a few short months after having your rotors resurfaced. To add insult to injury, when you replace damaged rotors, you’ll probably also need new brake pads as a result of the uneven wear caused by their hitting up against the warped rotors.
Replacing brake pads and rotors together
A complete brake service involves replacing both the pads and rotors. While more expensive upfront, replacing pads and rotors together will help both components last longer and ultimately give you the best brake performance. Replacing the full brake set also tends to be safer, as there is less risk of uneven wear or warping - both of which can reduce your stopping power.
Fortunately, new types of rotors are relatively affordable, especially when you factor in the cost of machining your old rotors only to replace them again at some point down the road. This may explain why more and more repair shops are recommending replacing rotors over resurfacing them.
How much do new brake pads and rotors cost?
When you take your car to a mechanic, new brake pads and rotors can run you anywhere from $250 to $1200 or more per axle. If you ask around at a few repair shops, each will quote you a different price depending on:
- The year, make, and model of your vehicle
- The quality and warranty that accompanies the parts
- Shop fees and labor costs
- Other services (like brake fluid replacement) included with brake repair
Below are estimates on brake pad and rotor replacement from a few different authorities around the web. You can assume that these ranges are for typical car makes and models, such as a Nissan Altima or Ford F-150. Ranges for performance vehicles will probably be higher.
Estimate Total Cost (per axle)
Kelly Blue Book
Pads: $96 - $113
Rotors: $110 - $217
Pads: $118 - $140
Rotors: $91 - $145
It’s important to note that choosing where to get your brake pads and rotors replaced based solely on price probably isn’t the best way to go about it. Discount brake service is often associated with hidden fees and cut corners when it comes to the quality of the parts. In other cases, discount brake service is offered as a way to get you in the door in the hope that you will agree to additional repairs that aren’t strictly needed.
Spending a little more upfront for quality brake repair can actually save you money in the long run. Higher-grade brake pads and rotors will wear better and last longer, meaning you’ll be less likely to end up back in the shop after having them replaced. They also tend to be backed with a better warranty.
What to expect after replacing brake pads and rotors
After replacing your brake pads and rotors, you might notice an odd smell coming from your brake system. While a bit unsettling, it’s generally nothing to worry about. Brake pads and rotors come with a resin-based coating on them. This helps to avoid corrosion and extend its shelf life before installation. Part of the process of breaking in (or bedding) new brakes is taking them out for a spin to help burn off the coating. To wear in new brakes, you’ll want to accelerate your vehicle to about 45 miles per hour and then engage the brakes to bring your speed down to about 5 miles per hour. Repeat that process four or five times, and you should be good to go!
If your brakes are making noise after new brake pads have just been installed, a lot of the time, it’s going to be as a result of the condition of your rotors. If there's corrosion or dirt and debris built up, you’re probably going to hear about it as it’s compressed between the brake pad and the rotor. Sometimes this goes away once the new brake pads settle in. While buildup doesn’t require that you replace your rotors right away, it can shorten the overall lifespan of your brakes and cause a bit of noisiness along the way.
Red flags to watch out for after replacing your brake pads and rotors include any reduction in brake performance or dragging upon acceleration. This could mean an issue with your brake caliper or a sign that your brake fluid needs to be replaced. Brake fluid is a hydrophilic substance, meaning that it draws moisture out of the air. So, if there is any exposure to the outside elements, it can sacrifice the integrity of the brake fluid. This can result in poor brake performance, where it takes a lot longer to stop. You know your vehicle. If your brakes are acting out of the ordinary after being serviced, it’s best to bring your care back to the mechanic to have another look.
What’s the best option for brake pad and rotor replacement?
At Nubrakes, we’ve designed our mobile brake repair service around convenience, affordability, and unmatched customer service - starting with a transparent pricing that you see before you book your repair. We service most any make and model and can come right to your home, office, or apartment to perform the repairs. Tell us when and where you’d like to schedule your brake service, and we’ll send one of our certified brake technicians out to wherever your car is parked.
Get started with a fast, reliable quote on professional mobile brake repair in your area. Simply send us a few details about your vehicle, and we’ll get back to you with a pricing estimate in under an hour.