Bad Rotors - 9 Signs You Need Quick Replacement

Brake rotors are a vital component of any vehicle. Naturally, the rotors sustain wear and tear due to regular use. You’ll hear clicking, grinding, screeching, and wobbling noises. The vehicle will vibrate when you hit the brakes. There are many such signs of a damaged/ worn-out brake rotor.

Unfortunately, it’s not a problem you can ignore or delay. Waiting too long to replace the damaged rotors will lead to complex issues. The other components like the brake pads, etc., will also get damaged because of this. Furthermore, it is risky to drive a car with bad rotors. Imagine the risk if the brakes fail.

Finding where the problem lies is not always easy. The issues with the brake system tend to have similar symptoms. In this post, we’ll understand the common signs to identify the bad brake rotors of your vehicle.

Common Signs/ Symptoms to Identify Bad Rotors

The brake rotors rely on friction to slow down and stop the car. Since repeatedly applying friction will cause wear and tear, the rotors will go bad over the years (or a few thousand miles). You’ll notice the signs as the rotors lose their efficiency and weaken.

Steering Wheel Vibrations

If the steering wheel shakes or vibrates each time you press the brake pedal, it signifies bad rotors. The brake rotors, calipers, and wheels are connected to the same spindle wheel. So when the rotors are no longer smooth or efficient, they start to vibrate. This vibration passes through the spindle and affects the steering.

The brake pads press against the smooth surface of the rotors when you hit the brakes. It produces a lot of heat and friction while slowing down the car. When this happens repeatedly, the rotors will wear out faster and bend out of shape or develop cracks. The heat and friction damage the rotors a little each time you apply the brakes. The rotors will go bad faster if you drive in heavy traffic, where you need to press the brake pedal often.

Braking Noises

Braking noises usually denote bad rotors, though they can also indicate other issues with the car’s internal system. It is dependent on the type of sound you hear when applying the brakes. If you hear a squeal when you use the brakes, it’s a sign of a worn-out rotor. This sound doesn’t go away after driving for a while.

If the sound does go away, you don’t have to worry about the braking system yet. It might be due to the change in weather or irregular use (if you don’t use the car often).

That said, squeaking brakes can also indicate worn-out brake pads. It won’t be long before the brake pads damage the rotors. Don’t wait too long when the car squeaks and squeals when braking. Take it to the mechanic. Inspect the brake pads and rotors to replace them.

Grinding Sound When Using the Brakes

Grinding noises are another sign of bad rotors and brake pads. Worn-out brake pads remove the buffer between the rotors and the metal backing plate. This leads to the metal directly rubbing against the rotors when you hit the brakes. Thus, you hear a grinding sound each time you use the brake pedal.

However, this is not the only reason for the grinding sound. Debris stuck inside the brake can also be a cause. Tiny stones, pebbles, or debris can enter the car and get stuck in the braking system. It affects the smooth functioning of the brake pads and rotors. The trouble here is that you cannot know what the actual reason is unless you inspect the brakes. It is safer to see for yourself than assume and ignore the problem.

Brake Pedal Pulsation

The brake pedal pulsates because of the same reason the steering wheel vibrates - a tremor through the spindle. A warped or bent rotor can affect the brake pedal but not the steering wheel. It can also cause vibrations in just one part of the car. A rotor at the end of its lifespan will repeatedly cause brake pedal pulsations.

The heat generated by friction is the main cause of this issue. You can prolong the rotor’s life span by investing in premium quality braking components and spare parts. Choosing the cheapest ones will lead to faster damage and frequent issues. Using stainless steel or ceramic rotors is a good option. These materials have a high tolerance for heat and will last longer.

Brakes Not Working Properly

Oversensitive or under sensitive braking is common with hydraulic disc brakes. The car will skid to a halt when you’ve barely put any pressure on the brake pedal. Or, you need to press the pedal really hard for the car to stop. This isn’t always a sign of bad rotors but an indication that the braking system is weak and will lead to damaged rotors.

For example, thinning brake pads, low brake fluid, and air in the brake lines can damage the rotors faster and lead to braking issues. Pay close attention to this aspect if your vehicle has hydraulic brakes.

Corrosion on Rotors

Corrosion or rust is common during rainy and winter seasons, especially if the car is exposed to bad weather. However, corrosion on rotors for a well-maintained and protected vehicle implies old age. The rotors are too old and should be replaced. Corrosion can reduce braking efficiency by 30%.

The rust causes grinding noises when the brake pads press against the rotors. That might be bearable for a while. But corrosion is dangerous as it prevents proper functioning of the brakes. It increases the risk of the brakes jamming and failing. Furthermore, replacing the rusty rotors is also difficult. Corrosion can eat away at the metal and affect other braking parts.

Corrosion is common in coastal areas and regions with high humidity. People in such states should be more alert about rust formation on the car’s components.

Delayed Stopping Distances

This is a clear sign of an issue with rotors and brake pads. Worn-out rotors aren’t effective on the brake pads. It takes longer for friction to work and slows down the car. Change and replace the rotors (and brake pads) immediately when you notice this. It’s highly risky to drive a vehicle that doesn’t stop when you hit the brakes.

Chemical Smell in the Car

Overheated rotors and calipers release a strong smell and lead to brake failure. An issue with calipers will put excess pressure on the rotors. This generates excess heat and bends the rotors. As a side-effect, you’ll notice a sharp chemical-ish smell coming from the brakes. There may or may not be smoke.

If you smell something different in the car after braking, make sure to stop at the closest possible point and allow the braking system to cool down. Then drive at a comfortable speed and avoid using brakes unless necessary. Replace the rotors and calipers (and brake pads) as soon as possible.

Grooves/ Marks on Rotors

If you aren’t sure about the sounds when braking, take a look at the rotors. Inspect the brake rotors’ surface. Does it look smooth? Does it have scratch marks and deep grooves? Touch the rotor (make sure it is cool) to feel the surface texture. A smooth rotor will be efficient and reliable.

But if the rotor has too many scratches or marks, it’s a sign of wear and tear. Ignoring the marks will lead to deeper groves and excess damage. It will also affect the braking performance and damage the brake pads.

Cracks on the rotor’s edges are dangerous. While slight cracks are not a cause of alarm, they indicate that the rotors should be replaced in a few months. Deeper cracks can cause brake failure or snap the rotors into two. Either situation can lead to accidents and injuries.

Easy Checklist to Detect Bad Rotors

Use the below checklist for easy reference to identifying the signs of worn-out/ bad brake rotors.

How to Ensure if the Rotors Need Replacement?

Check the brake pads and rotors during every maintenance/ servicing session. Take the rotor thickness and compare it with the manufacturer’s guidelines. If the rotors are thin, replace them immediately.

In some vehicles, the ABS (anti-lock braking system) light will blink on the dashboard. It indicates the need to inspect the rotors and brake pads (for replacement).

Rotors don’t warp easily but it can happen in rare instances. However, pad deposits are a common occurrence and cause the rotors to wear out. It is best to change the entire setup even if only one rotor is worn-out. It is not worth the risk.

Final Words

Resurfacing brake rotors was a preferred choice a couple of decades ago. However, rotors are now cheaper and easier to replace. Resurfacing is not recommended in the long run. You’ll end up spending more and risking your life.

Once you identify damaged/ broken/ warped rotors, replace them as soon as possible. Use our checklist to detect the problem correctly and take the necessary action.