When To Replace Brake Rotors? Every Thing You Need To Know!

Do you know when to replace brake rotors and how to do it? 

Shaking or shuddering, grinding noises or metallic squealing coming from the brakes, or a steering wheel pulling to one side when decelerating are all probable warning signs that you may need to fix or replace pads or rotors on your car.  

Fortunately, these symptoms can be easily diagnosed by a mechanic. So if you observe any of them, bringing your car to an auto repair shop for a check up as soon as possible is what you should do. 

In some cases, resurfacing rotors or switching out brake pads are enough to repair the problems. However, if your car has severely damaged parts, it will need a brake rotor replacement immediately.

So let’s find out “What are brake rotors?”, “What causes brake and pad problems?” and “How to tell if you need new rotors?” in this article.

What Are Brake Rotors?

Before knowing why and when to replace brake rotors, it is useful to understand precisely about what these components are and how they operate. 

Brake rotors, also called brake discs, in most cars, are metallic discs which you can see visually through the wheel wells.

Brake rotors work together with calipers and brake pads to decelerate the rotation of the wheel and then stop the car. The principle of this system is the same as rim brakes on a bicycle. 

When pressing the brakes, the calipers compress the brake pads against a slewing surface. This will result in a frictional force that reduces the speed of the wheels and enables for a halt.

While in a bicycle the brake pads press against the wheel rim directly, in a car the brake pads press against the brake disc (brake rotor). The brake disc itself is attached to the wheel hub and rotates in synchronization with the wheel.

As the force to stop a car is much higher than that of a bike, brake discs are necessary to absorb and dissipate the resulting pressures and temperatures.

Brake rotors
Brake rotors are metallic discs which you can see visually through the wheel wells. (Photo: Your Mechanic)

What Are Causes Brake Rotor And Pad Issues?

To ensure the effective work of the braking system, the rotor surface needs to be fully flat and smooth. The brake pads need to keep continual contact with the brake rotor when slowing down the car. 

If the rotor surface is grooved or warped, the pressure of the pad will be inconsistent, causing shuddering or pulsing during deceleration.

The most common issues with the brake rotors are scoring and deforming. If the brake pads have been worn out, it will cause scoring. 

Gradually, this pad is gone, the underlying metal scapes squeeze against the brake rotor when decelerating the car. For a long time, this can result in a deep groove on the surface of the rotors.

Brake motor deformation is a consequence of exaggerated braking, that can lead to hard overheating capable of warping the brake rotor. And if another part of the braking system is malfunctioned, it will result in warping as well.

What To Do To Fix The Brake Rotors?

In case your brake rotors are not damaged seriously, a skilled mechanic can machine the rotor to make a smooth and flat functioning surface. 

At the same time, your car does need new brake pads. Although your old brake pads are still in good condition, the frictional material has likely worn unequally because of rotor damage. 

Therefore, it is better to install new brake pads to ensure constant, flush contact with the brake discs and smooth function of the braking system.

machine the rotor
A skilled mechanic can machine the rotor to make a smooth and flat functioning surface. (Photo: One Project Close)

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But keep in mind that we can not resurface the brake rotors too many times. Brake rotor makers set a minimal thickness in order to ensure the exact rotor function. 

If you machine the rotor a lot, this part will be worn out and lose the ability to dissipate and absorb heat. 

So in this case, a skilled mechanic should be able to give you advice as to whether resurfacing rotors is effective or your car needs a new brake rotor.

When To Replace Brake Rotors?

As rotor composition and design vary between various models and makes, the average lifetime of each brake rotor will also vary. 

Knowing when you need a brake rotor replacement will also be up to your driving style. If you often drive in the city, you will definitely need to replace brake pads and rotors more than if you almost drive a longer distance.

Our auto experts advise you should replace the brake pads regularly in order to avoid switching out rotors too soon. 

And the best way to prevent brake system problems is to have your mechanic do a routine check during your regular oil change.

Watch the video from Helpful DIY to know how to tell if you need new rotors?

Hopefully after reading this article you will get a deep knowledge about what brake rotors are and when to replace brake rotors. 

If you have any questions, please feel free to leave it in the comment section and we will discuss further.