Brake rotors, or brake discs, are essential components of modern automobiles, but not everybody is aware of their use or even their existence.
A brake rotor makes up part of a vehicle’s braking system, working to slow down or stop a vehicle. During braking, the brake pad is pressed against the spinning rotor to create friction, which slows down the rotation of the wheels and therefore the vehicle.
We’ve compiled a handy list answering the most common queries about brake rotors, so keep reading to find the answers to your questions as well as many others.
1. How Do You Know if Your Rotors Are Bad?
There are several warning signs that could indicate your brake rotors are bad, and below we go through them.
The first sign you are likely to notice is a squealing, squeaking or even grinding sound when braking.
This sound could be the result of a warped brake rotor, but it may also be the result of a worn brake pad.
However, what’s certain is, if you hear an unusual noise, it is always worth checking it out before it gets any worse.
Vibrations While Braking
Another indication of bad brake discs that you would be sure to notice, is an excessive vibration or a pulsation as you brake, either through the brake pedal or occasionally the body of the car.
This vibration is caused by the brake pad pulsating over a warped, or uneven, brake rotor, and the only remedy for a warped disc is to replace it.
Perhaps the easiest method on this list to tell whether your brakes need attention is if your car is equipped with sensors that warn you of this via a light on the dashboard.
Unfortunately, not all cars have this handy feature, so it’s best to check your car’s manual to see whether you can expect to see this when the time comes.
Scoring or grooves on the brake disc suggest a rotor change may be needed, as over time the surface of the disc wears away and once it reaches a certain point it reduces the vehicle’s overall safety.
Other visual signs can include rust and cracks on the surface of the brake rotors, so if you notice any of these things it is best to look into getting them replaced.
If your car’s wheels have adequate gaps, simply looking through the spokes will give you a view of the brake discs.
It is good practice to visually inspect your brake rotors regularly, particularly if your car doesn’t have sensors.
2. What Happens if Your Brake Rotors Are Bad?
As you might have guessed, driving with damaged or warped brake rotors can be dangerous, particularly because they might seem functional while driving normally.
A worn, thin brake rotor can negatively impact the vehicle’s ability to brake effectively, resulting in longer stopping distances.
This could prove to be less than ideal when emergency braking, for example.
Additionally, warped brake discs are more likely to suddenly crack or break due to the brake pad constantly wearing them away over time, leading to potential damage to other parts of the wheel and the complete failure of that particular brake.
3. When Should Brake Rotors Be Replaced?
Brake rotors are one of the most durable components of your car, but like most things they wear down with repeated use and in general should be replaced every 30,000 to 70,000 miles, or roughly 50,000 to 110,000 kilometers.
Yet there is no fixed answer to this question, and the range between these figures indicates how the lifespan of a brake disc varies depending on driving style and environment, as well as the quality of the brakes.
For example, braking hard to come to a stop will wear down the brake rotors quicker than a more gradual braking action will, and city driving requires more braking than long, straight roads like highways.
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4. Do All Brake Rotors Need To Be Changed at the Same Time?
You don’t have to change all four brake rotors at the same time, but it is recommended to replace them together as a set of two, i.e. for the front or back axle.
It is also a good idea to change the brake pads when you change the brake rotors to avoid uneven wear to both parts.
5. Do Brake Rotors Come in Pairs?
Brake rotors are usually sold individually, but they should be changed in pairs according to the axle they are on.
This is to ensure that your vehicle brakes in a balanced way and doesn’t pull to one side when braking, a phenomenon that happens when one wheel brakes more than the other.
6. Do Brakes and Rotors Come Together?
A vehicle’s brakes are made up of multiple parts, but is it possible to buy brake rotors and brake pads both together as a set and individually.
7. Do Brake Rotors Rust?
Since they are made from steel, brake rotors do indeed rust, and it is one of the visual warning signs which can indicate that they need changing.
In spite of this, a small amount of rust is normal, and if you drive your car regularly it shouldn’t impact the brake’s functionality as the rust will be cleaned off the brake discs by the brake pads when driving.
It may become a problem though if you do not drive your car for a while, for instance between 6-12 months, because it allows the rust to build up, causing pitting in the brake disc which can reduce the vehicle’s braking power.
8. What To Do With Old Brake Rotors?
Most brake rotors are made entirely from metal, so if you have a few old ones it could be worth selling them as scrap to earn a bit of spare cash.
Otherwise, it depends on how creative you are.
Rotors are non-toxic, so you can do anything from simply throwing them away to repurposing them as a lamp stand, dumbbells; the list goes on.
Alternatively, if you wanted to get rid of them, posting an advert on social media for someone to take them off your hands could save you a trip to the junkyard.
9. Can You Put Brake Rotors in the Recycling Bin?
While you can recycle brake rotors, you can’t usually put them in the regular recycling bin along with other metals because they are chunky and heavy.
It is always worth checking with your local waste management center first, but in order to recycle them properly you will likely have to take them to a junkyard.
Despite your best intentions to be environmentally friendly by putting your old brake discs in the standard recycling bin, they could end up in landfill if your waste management service is unable to process them with the smaller, regular metal items.
That being said, if you have a high-end sports car, there’s a chance you may have carbon-ceramic rotors.
These types of brake rotors are non-recyclable, so they should be thrown in the trash.
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10. Are Brake Rotors Covered Under Warranty?
It is worth checking the fine print of your individual warranty, but generally, brake rotors are not covered under warranty because they are classed as “wear and tear” parts.
It can also depend on when they malfunction though, as some warranties will cover them if they need replacing within the first year or 12,000 miles since this would be classed as premature wear.
11. How Much Do Brake Rotors Weigh?
Brake rotors are pretty sizable, and they can weigh between 15-30 lbs.
Therefore, if you have a lot of them lying around, it may be worth seeing how much you could get for them as scrap.
It won’t be a fortune, but it could be a good way to clear some space while getting money for old rope.
12. Does AutoZone Take Old Brake Rotors?
Unfortunately, AutoZone does not take old brake rotors.
If you are looking to get rid of your old brake discs, search for a local dealer or recycling center to see whether or not they can take them off your hands.
13. How Much Are Used Brake Rotors Worth?
A worn-out brake rotor that is not suitable for reuse is only worth its weight in scrap.
Scrap prices constantly fluctuate, but you can probably expect to receive one or two dollars per rotor.
If you are considering purchasing used rotors or reusing your old ones, there are strict criteria that have to be met to ensure that they are safe to use.
14. Can You Put New Brake Pads on Old or Damaged Rotors?
Mechanics and car professionals advise against putting new brake pads on old rotors for two reasons: the vehicle’s braking power will be reduced since it will be harder for the pad to connect with the brake disc’s surface; and a worn, uneven disc surface can damage the brake pad material as well.
15. Can You Paint Brake Rotors?
You can paint brake rotors, and many drivers do it to personalize their cars since the discs are often visible through the spokes of the wheels.
Moreover, painting brake rotors with certain kinds of paint can reduce the possibility of them rusting, so there is a practical reason for doing it, too.
16. Are Duralast Brake Rotors Any Good?
AutoZone’s own Duralast brake rotors are a popular choice and are rated highly among those who use them due to their value for money.
There are, however, people who have encountered problems with the Duralast brake discs and believe in the importance of paying a bit more for better quality.
The positive reviews outweigh the negative, but it is always worth shopping around before making a decision to work out what’s best for you.
That being said, high performance hardware aside, Duralast’s brake rotors should do the job just fine.
17. Do Black Brake Rotors Stay Black?
Black brake rotors will be stripped of their coating and turn silver as soon as you start braking on their first outing.
This happens because when the brake pads press against the brake discs during braking, the friction causes the discs’ zinc coating to be rubbed off, leaving the silver underneath.
The rotor’s holes and slots will retain their original color, but the black disc surface itself will be stripped.
Final Thoughts — Brake Rotors
Hopefully this article has answered your questions and more so that you are now fully informed about brake rotors.
Seeing as how brake discs are such an important component of a car, it’s worth knowing how to spot the warning signs and how to deal with any problems that may arise so you can drive comfortably and confidently.
Ultimately though, if you are worried about something on your car, the best advice is to go to an experienced mechanic to get it checked out.