15 Symptoms of a Faulty Rotor (How to tell if a rotor is bad)
A warped brake rotor is a problem caused by daily wear and tear that you shouldn’t ignore. Not only does fixing it become more expensive the longer it is postponed, but it is also one of the worse problems to have, given the degree of risk it places a driver in when driving. Some of its signs start slowly and might not be obvious to someone who doesn’t know what to look for. That’s why it’s important to know how to detect a faulty brake rotor.
There are a few ways to tell if a rotor is broken. Symptoms like: wobbling, blue marks, grooves/scoring, pulsation/vibration, and screeching or grinding noises lead to damaged rotors or another braking component, and you can detect this by feel, sound, or visual inspection.
Here are 15 common indicators of a faulty rotor:
- Steering wheel vibrations
- Pulsating brake pedal
- Reoccurring brake noises
- Grinding after applying brakes
- Screeching after installing brake pads
- Out-of-round rotors
- Deep grooves or score markings
- Worn-out rotors
- Blue spots
- Corrosion
- Heavy chemical fumes
- Wobbling
- Uneven and inconsistent braking
- Insensitive/hypersensitive brakes
- Increased stopping distances.
Even for people who have owned cars for a long time, it’s not easy to figure out what makes rotors wear out quickly. But with a little help from this guide and more experience fixing things, you should be able to detect a faulty rotor.
Signs of a Faulty Rotor
Steering wheel vibrations: When you hit the brakes, the brake pads press against the smooth, flat surface of the rotors to stop or slow down your car. Because of this friction, the brake rotors get very hot and under a lot of pressure. Over time, this causes the rotors to become bent, uneven, or warped. From a structural point of view, the rotors and the calipers are both connected to the same spindle where the wheels are. So, if the rotors lose their smoothness, the vibrations or feeling of unevenness travel through the spindle and reach the steering wheel. Even if the rotors and brake pads are in good shape, the steering won’t feel as smooth as it used to.
Pulsating brake pedal: This sign is caused by the same culprit as the first one on this list: brake rotors that are warped, bent, or uneven. However, most of the shaking is felt in the brake pedal, not the steering wheel. This sensation could be fully isolated in that area or noticed in other parts of the vehicle. The pulsing could also be because your rotors are having too much runout.
One way to keep your brake rotors from warping is to ensure your brake parts can get rid of heat properly. Since heat is made by friction, when your brakes stop your car, brake parts shouldn’t heat up too much. If it does, the intense heat can cause the brake rotors to buckle, making other parts more likely to break or get damaged.
Not replacing the rotors when they need to be is also not a good idea. Cheaper, lighter brake parts don’t have enough material to get rid of heat, which may just make things worse. Ceramic, stainless steel or cross-drilled and slotted brake rotors are the best replacements because they can handle heat better and get rid of it more quickly.
Reoccurring brake noises: People often think that brake noises that don’t go away mean the rotors are bad. This may not always be true. It takes a good ear to tell the difference between the sound of a broken rotor and the strange sound of a car left out in the rain overnight. This latter sound is normal, and it goes away after a while. It is avoidable if you keep your automobile indoors in chilled weather.
You should be on the lookout for squealing, which is a sign of worn brakes or severely damaged brake pads. After all, the brake pad wear indicator only makes noise when it hits the brake rotor. The noise could also be caused by a dirty car or too much brake dust.
When this happens, you need to fix your brakes and change the brake pads immediately. Using worn pads on the road is a huge safety risk. It can cause other brake parts to heat up too much and cause too much brake material to build up on the rotors. Another thing to watch out for is scraping, which is an indicator of worn rotors and pads. Most of the time, rotors that make scraping sounds already have deep grooves or edges.
Grinding after applying brakes: Another way to tell if a brake rotor is faulty is if your car makes grinding noises when you try to stop. This noise is made by brake pads that have worn down to the metal backing plate of the brake system. In this case, the latter rubs against the surface of the brake rotor, making the sound. Either that, or there’s a pebble or something else stuck in your brakes.
Whether the grinding sound is caused by debris or not, your brake rotors are broken and need to be replaced with new ones. If you think that something else aside from your brakes is making the grinding sound, have a professional take a look. Also, you should change your brake pads simultaneously to ensure that the area where the rotors and brake pads touch is the same on all four corners of your car.
Screeching after installing brake pads: Even though it takes some time for new brake pads to get used to the car, loud screeching sounds are not normal. If you hear this high-pitched sound, it means the rotors are glazed or that the edges are burned from being too hot. When you look at the rotor, you may also see blue marks or a dark ring, which I discussed in more detail in a later section of this guide. If you just got new brake pads and haven’t had them for a while, going easy on the brakes when driving fast may stop or cut down on the screeching. If otherwise, then maybe it is time to get a new set of rotors.
Out-of-round rotors: Aside from strange sounds from the car, you can also tell if a rotor is bad by looking at the brake parts. Regular checks allow drivers to tell the difference between a good rotor and a bad one. Most of the time, they find a lip or thinning around the edge of the brake rotor, especially on older cars with brakes that have been used a lot. However, if you want to know if your rotors are out of round or need to be resurfaced, you will need to measure the thickness and roundness of each rotor face with the proper devices. You can also allow an auto shop to take care of it for you.
Deep grooves or score markings: A good brake rotor usually has a flat, smooth surface that you can see and feel. The brake pads don’t wear too deeply into the rotor because the face of the rotor is smooth.
When the brake pads don’t make good contact with the brake rotor, the brakes won’t work as well as they should. This is because the brake rotor is damaged. Even though these flaws get worse over time, they can sometimes show up because of how you drive or use your brakes. If you see grooves or scoring on the rotor face, you need to replace the brake rotor and pads immediately. You should not write off or ignore this sign.
Worn-out rotors: Brake rotors can get cracks or gouges when heated to very high temperatures. The brake rotor develops dents on its surface from the excessive heat. As long as these cracks are only on the surface, they don’t affect how the brake rotors work. But deeper cracks are more dangerous and may even be signs that a brake rotor is about to break in half.
Unlike tires, which only need to be replaced when the tread wears down to a certain point, it is not a good idea to use a brake rotor until it starts to run out. Even before you get to that point, it’s likely that stopping your vehicle has already caused you a lot of trouble. It would make no sense and it’s dangerous to keep driving with a damaged rotor.
Blue spots: Blue spots on your brake rotors are usually a sign of bigger problems, like cracks in the rotors, broken calipers and brake shoes, wonky wear on the brake pads etc. The discoloration is caused by too much heat from riding the brakes, brake calipers that aren’t aligned, or stock brake parts that can’t get rid of enough heat. In some cases, it’s because the brake pads are being pressed on even though the brakes aren’t being used.
If you see blue rotors, you should check your car’s brakes. It will be in your best interest to find out which of the above parts are faulty or need to be replaced so that you don’t have bigger problems with your brakes. For better heat dissipation, veterans suggest replacing discolored rotors with cross-drilled slotted rotors and brake pads with ceramic ones.
Corrosion: Due to moisture buildup in the car and brake system components, cold and wet seasons can cause corrosion. Well-maintained and garaged cars are a different story. Replace your brake rotors if you see corrosion around their edges.
Slight rotor rust can cause grinding noises and difficult braking if ignored. Rust would pit the brake pads, contact area, and vanes. Oxidation can cause brake rotors to stick, making them harder to remove and replace.
Heavy chemical fumes: Chemical odor coming from your car could mean that the brakes are too hot or that one of the calipers is stuck in place, which could cause the brakes to fail. Brake calipers that don’t work properly put too much stress on the brake rotor, which can cause it to warp or get out of balance. Sometimes when a wheel is broken, smoke comes out of it. When brake rotors get too hot, they give off a sharp, unpleasant smell but don’t make any smoke.
If you notice any of these things, pull over to the side of the road and allow your brakes cool. After taking a break, you can drive again, but be careful when you use your brakes. When you get to a safe place, you should fix or replace your brake pads, calipers, and rotors immediately.
Wobbling: Contrary to what most people think, wobbling or shaking is an early sign of worn-out wheels and broken wheel bearings. The latter occurs when driving at speeds more than 70 mph, resulting in warped rotors and uneven brake pad wear. Wheel runout must still be examined because it has a harmful effect on how a brake rotor performs. It’s also vital to ensure the wheel bearings are tightened to the right amount and in good shape.
Uneven and inconsistent braking: A car pulling to only one side when the brakes are applied could be because of a bad brake hose or a problem with the caliper. At first, it might be hard to figure out the problem. But once you do, it’s easier to tell whether the front or rear brakes are broken.
If one brake seems to work harder than the other and only pulls the car in one direction when you stop, it’s likely your front brakes are to blame. If the unevenness of the brakes is almost negligible, it’s likely that the rear brakes need to be checked and that the rear calipers aren’t functioning properly.
Insensitive/hypersensitive brakes: Noticing this early makes a huge difference in how much the owner will spend on repairs and new parts, especially for cars with brake discs that operate with hydraulics. There are two sides to this issue. One is that you barely touch the brake pedal, but it still works. The other is that you have to press the pedal almost all the way down to the bushing to get it to work.
If either of these things happens when you press the brakes, it could imply that your brake fluid is low, there is air in the brake lines, your brake pads are too thin, or there is a bigger problem with your vehicle’s hydraulic system. Even though these things don’t directly affect your brake rotors, they will work in the long run if they aren’t diagnosed and fixed.
Increased stopping distances: This is the most visible indicator of a damaged brake rotor in the absence of smell or touch. Experienced drivers can spot brake system issues by their performance. Warped/faulty brake rotors would naturally impair a vehicle’s braking mechanism. Brake fade may occur regularly.
High-performance driving or steep descents cause brake fade. Contaminants on the brake rotors cause the brake pads to slip and slide. However, repeated brake application, especially in high-speed or heavy-load circumstances, might cause damage over time. Chips and uneven surfaces on worn rotors impair brake performance because the pads get less braking surface.
Conclusion
In summary, the following are 15 common symptoms of a faulty rotor:
- Steering wheel vibrations
- Pulsating brake pedal
- Reoccurring brake noises
- Grinding after applying brakes
- Screeching after installing brake pads
- Out-of-round rotors
- Deep grooves or score markings
- Worn-out rotors
- Blue spots
- Corrosion
- Heavy chemical fumes
- Wobbling
- Uneven and inconsistent braking
- Insensitive/hypersensitive brakes
- Increased stopping distances.
Keep in mind that you shouldn’t drive around with a faulty rotor or if any of these symptoms keep happening. Replace warped rotors immediately or hire a professional to take care of the problem if you can’t change it yourself. Even the best brake rotors will lose their quality over time. However, if you drive carefully, run routine maintenance, and do all the regular inspections, you should be able to avoid costly repairs and more damage to the brake system.
