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Understanding Bad Rotors: Signs and Symptoms

What are Bad Rotors?

Okay, imagine you have a spinning top that you play with. It should spin smoothly and not wobble too much when you turn it. Now, your car has something similar called a rotor, which is a part of your car's braking system.

The rotor is like a flat, round metal plate that spins when your car moves. When you want to stop your vehicle, unique parts called brake pads press against the rotor, and the friction between them slows the car down.

If the spinning top isn't made well, it might wobble when you spin it. The same thing can happen with a car's rotor. If the rotor is not in good condition, it can cause problems when you try to stop your car.

This is called having bad rotors.

When you have bad rotors, you might feel your car shake or vibrate when you press the brake pedal. You might also hear strange noises, like squeaking or grinding.

These signs tell you that your car's rotors might not be working correctly, and it's time to have them checked by a professional mechanic.

Key Takeaways:

  • Rotors are crucial components of your car's braking system. They work with brake pads to slow down your vehicle. Bad rotors can cause vibrations, strange noises, and poor braking performance, risking your safety.

  • Some common symptoms of bad rotors include vibration or pulsation in the steering wheel, high-pitched squealing noise when braking, shaking steering wheel, brake pedal pulsing, vehicle taking a long time to stop, loud bangs while braking, large edges on the outer part of the brake rotor, and scratch marks on the rotor.

  • The most common reason for brake rotor failure is wear and tear due to regular use. Other reasons include warping from overheating, cracking in the machined surface, or damage from rust.

  • Replacing bad rotors is essential for safety, brake performance, preventing damage to other components, noise reduction, and improved fuel efficiency. Regular maintenance and timely replacement of worn or damaged rotors ensure a safer and more comfortable driving experience.

Table of Contents

8 Symptoms of Bad Rotors

Vibration or pulsation in the steering wheel

If you notice any vibration or pulsation in your steering wheel, this may be due to rust on the brake rotors or if they could be imbalanced due to overheating. You should have the rotors evaluated by a trustworthy mechanic to see if they need to be repaired or replaced.

Note: If the problem is discovered early enough, a mechanic can "turn" (resurface/machine) the rotor to remove the damaged surface while maintaining the rotor's minimum thickness. If the warning indications are disregarded, the rotor might be damaged to the point where it wears to an unsafe thickness, putting your braking system at risk.

High-pitched squealing noise when braking

If you hear a high-pitched squealing sound whenever you press the brake pedal, it's important to inspect your brake rotors for any damage, brake dust buildup, or edges. When brake rotors become worn, they develop an uneven surface and edges on both the interior and exterior surfaces. When you drive normally, but especially when you apply force to your brakes, these edges and surfaces can produce a high-pitched sound.

When brake rotors become worn, they tend to develop many uneven surfaces, resulting in less "braking surface" on the brake rotor for the brake pads. This will drastically degrade your brake efficiency.

The steering wheel is shaking

When your front brake rotors fail, you will usually feel it in the steering wheel. This could be due to brake rotor rust or if they were unbalanced due to overheating. If you notice that your steering wheel shakes when you stop, it's time to check your front brake rotors.

Brake pedal pulsing

If you push the brake pedal and it feels like it is pulsing, it could be due to rust on the brake rotors or uneven surfaces. The front and rear brake rotors can create a pulsating brake pedal while braking; however, if the front brake discs fail, you will most likely feel it in the steering wheel.

The vehicle takes a long time to stop

If your brake rotors are worn, they create uneven surfaces which give the brake pads less braking surface on the brake rotor. This can cause your vehicle to take longer to stop.

Loud bangs while braking

If you hear loud bangs while braking, this could mean that your brake rotor is cracked. In this case, you should replace it immediately because you could lose the entire brake function and cause accidents.

Large edge on the outer part of the brake rotor

If you compare the edge on the brake rotor’s inner or outer part in comparison to a new one and it looks larger than it should, this could mean that your brake rotor is worn down.

Scratch marks on the rotor

If you look behind the rim to see the brake rotor and see a lot of scratch marks on it, it's probably time to replace the brake rotors. All brake rotors develop a few scratch marks soon after installation, but if you see a lot of deep scratch marks, it's time to replace the disc rotors.

Stones caught between the brake pad and the rotor are a common source of deep scratch marks. Strange noises heard while braking is probably caused by stones.

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Brake Rotor Overview

Brake rotors are circular discs linked to each wheel and used to convert kinetic energy to thermal energy. When you press down on the brake pedal, the master brake cylinder sends a signal to your brake calipers which causes your brake pads to pull together against the rotors' large surface area. The friction caused by the pads pressing on the rotors resists the wheel's spin, slowing its rotation and bringing the car to rest.

There are 4 different types of rotors:

  • Blank and smooth: Most passenger vehicles use a smooth, blank metal surface around the rotor.
  • Drilled: Drilled rotors have drilled holes all over the metal surface.
  • Slotted: Slotted rotors have long "slots" or lines etched onto the metal surface.
  • Drilled and Slotted: Drilled and Slotted rotors combine drilled holes and slots for improved performance.

Fortunately, finding the proper rotor for your car is as simple as looking at the installed ones. When replacing your vehicle's rotors, remember that the rotors on your family car will most likely not fit on your pickup truck and vice versa.

How Good Brake Rotors Work

Good brake rotors provide a smooth surface for brake pads to press against, allowing efficient conversion of kinetic energy to thermal energy.

When the brake pedal is pressed, brake fluid is forced through brake lines, causing the calipers to squeeze the brake pads against the rotors. This friction generates heat and slows down the rotation of the wheels, bringing the vehicle to a stop.

High-quality brake rotors ensure consistent, effective braking performance and a safer driving experience.

Here is an overview:

  • The driver presses the brake pedal.
  • Brake fluid is forced out of the reservoir by a plunger in the master cylinder.
  • Fluid flows to the wheels through inflexible brake lines.
  • The fluid is then carried into the calipers by flexible brake lines.
  • The fluid pressure pushes out the brake pistons in the calipers.
  • The pistons press the brake pads' backing plate.
  • The braking rotors and pads push against each other, with the pad linings compressing the rotor surface from both sides.
  • The friction causes the car to slow down or completely stop.
  • The brake rotors and pads reach a high temperature due to the heat generated.

Reasons Why Brake Rotors Stop Working

Wear and tear is the most common reason a brake rotor becomes unusable. Brake rotors wear out every time you apply the brakes while driving your vehicle. The brake rotor material gradually wears away with time and regular use.

Other brake rotor defects include warping beyond resurfacing due to repeated severe use. The surface of any metal repeatedly heated above its tolerance and then rapidly cooled becomes twisted over time. This can occur when your vehicle is subjected to significant brake demand, such as traveling through hills or mountains, towing a boat or trailer, or carrying additional baggage.

Brake rotors can occasionally develop cracks in the machined surface. When a brake rotor develops a crack, it must be replaced to resolve the problem and ensure proper braking performance safely.

How Often Should Brake Rotors Be Replaced

Brake rotors will need to be replaced over time due to the amount of use they receive. The wear lasts between 50,000 and 100,000 kilometers and is caused by continual friction. They also tend to distort when heated by friction and subsequently driven through water, necessitating the replacement of rotors. You will notice wear and other concerns with the brake rotors because they are required in the braking operation of the car.

How to Increase The Lifespan of Brake Rotors

To extend the lifespan of your brake rotors, practice using only one foot to operate the gas and brake pedals, as this technique can contribute to the overall longevity of your brake system.

Avoid simultaneously pressing the brake and gas pedals, a common racing tactic, as it can inadvertently cause wear to your brakes and negatively impact fuel efficiency. Refrain from unintentionally resting your foot on the brake pedal, as this can lead to premature brake pad wear and excessive heat, both of which can damage the rotors.

Why do we need to replace Bad Brake Rotors?

Replacing bad brake rotors is essential for several reasons:

  • Safety: Worn or damaged rotors can reduce the braking efficiency of your vehicle, increasing the risk of accidents due to the longer stopping distances or a potential brake system failure. Ensuring that your brake rotors are in good condition is crucial for the safety of you, your passengers, and other road users.

  • Brake Performance: Bad rotors can cause uneven or pulsating braking, leading to poor vehicle control and reduced brake performance. Replacing bad rotors can restore your vehicle's braking performance and provide smoother, more consistent braking.

  • Prevent Damage to Other Components: Damaged or worn rotors can cause uneven wear on your brake pads, calipers, and other braking system components. This can result in additional repair costs and potentially compromise the integrity of the entire braking system. Replacing bad rotors can help prevent further damage and extend the life of other braking components.

  • Noise Reduction: Worn or damaged rotors can cause squealing, grinding, or other unpleasant noises during braking. Replacing bad rotors can help eliminate these noises, providing a more comfortable and quiet driving experience.

  • Improved Fuel Efficiency: Poor braking performance due to bad rotors can affect your vehicle's overall efficiency. Efficient braking contributes to better fuel economy, so maintaining your brake rotors can help save on fuel costs in the long run.

Don't compromise on safety - choose NuBrakes Mobile Brake Repair for all your brake maintenance needs!

Bad brake rotors can put you, your passengers, and other road users at risk. Restore your vehicle's braking performance, prevent damage to other components, reduce noise, and improve fuel efficiency by trusting NuBrakes with your brake rotor replacements.

Our team of certified technicians comes to you, making the process convenient and stress-free.

We are committed to providing top-notch service and ensuring your vehicle's braking system is in the best possible condition.

Schedule your appointment with NuBrakes Mobile Brake Repair today and experience the difference in safety and performance!


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