What Causes Brake Rotors To Warp?

180 Automotive is reader-supported. This post contains affiliate links. As an Amazon Associate I earn from qualifying purchases.

The question ‘what causes brake rotors to warp’ is a recurrent concern, especially among car owners and drivers.

There are a number of reasons your brake rotors can warp, including:

  1. Excessive High-Speed Braking Extreme Heat
  2. Extreme Heat
  3. Physical Damage
  4. On-surface Soft Glaze
  5. Caliper Or Pad Misalignment

Many drivers and car owners are not aware of the parts that make up the braking system of their car. The rotors are an essential component of the braking system. They work in sync with the brake calipers and brake pads to slow down your car or bring it to a stop.

What Are Warped Rotors?

When the rotors damage (or warp, to use the more technical term, the brakes of your car will start to malfunction or stop working. But what does warping mean? Warping is a technical term that refers to the flat or uneven surface of the brake rotors and it’s usually caused by extreme heat.

5 Causes Of Warped Rotors

1. Excessive High-Speed Braking

When you drive at a high speed, chances are that you’ll have to apply much force on the brake pedal. When this happens, the rotor is often the immediate victim. The gliding of the pads against the rotors will be more forceful and so could cause the surface of the brake rotor to become uneven and warped.

2. Extreme Heat

If you understand the internal mechanism of the braking system, you’re not likely to join the category of my ignorant neighbours and colleagues. They argue that the rotors can’t get hot to the point of warping permanently.

Here’s where they got their position wrong. Extreme heat can cause the rotor to become so intensely hot that it wears down the brake pads. Don’t forget, when you’re braking, the brake pads often make a contact with the rotors to slow down your vehicle.

However, once the pads wear out, they become thinner and lose their density. What you’ll experience between the two parts is metal to metal contact. This doesn’t only cause a grinding noise but also leaves some bluish tint on the rotors and eventually make them warp.

3. Physical Damage

Another cause of rotor warping is the wearing down of the surface of the rotors. This physical damage causes harder spots to form in the metal stay, resulting in some slightly bloated rotor surface. The friction-applying brake pads are designed with a softer material than the meta of the rotor.

So, when you drive and apply the brake, the pads wear down quite quickly but the rotor remains strong. However, as more and more heat softens the pads, the surface of the rotors also start to weaken, thin out, lose its density, and then finally warp.

4. On-Surface Soft Glaze

The glaze is a concept that’s not thrown around too frequently; you’ll hear mostly used among professional technicians, and may some experienced car owners. In any case, the glaze is a lax mirror-like material formed on the surface of the brake rotors of your car.

How does it form? Your brake pads are designed with a highly heat-resistant metallic friction material. This friction material can become so hot especially when you’re having a prolonged riding on the brake or you’re driving at a high speed.

Once the friction material becomes extremely hot, it will slacken and so form a glaze on the surface of the brake rotors. However, the grippy material will first paint the rotors before the soft-mirror glaze is formed.

Consequently, the brake pads won’t grip well onto the metal when you press on the brake pedal glaze stops or reduces the stopping and slowing-down power of the braking system and the brakes will fail your car.

5. Caliper Or Pad Misalignment

Some installation errors can also cause the brake rotors to warp. For instance, if the brake pads or brake calipers are not properly aligned during installation, you may notice that the rotors on its surface have an uneven shape.

This warped surface of the rotor is largely due to one side of the caliper sticking out. This misalignment of the caliper will result in overheating and so cause more wear on one side of the rotors.

Make sure the calipers of pads are properly aligned to prevent glaze from forming on the surface of the rotors.

How To Fix Warped Brake Rotors

You may have heard the myth making the rounds that resurfaced brake rotors can hardly restore the lost frictional firepower of the rotors. That’s not true. In fact, let me burst your bubble: resurfacing glazed rotors can be a better option than going the hog of replacing them. But that’s a limit.

By resurfacing, it means that your technician is providing your car’s brake rotors with a smoother and better finish after the previous damage caused by the overheating of the brake pads.

Once resurfaced, therefore, the rotors’ surface will become flat and even while the rotors will regain their grippy power for proper braking.

On the flip side, sustained resurfacing will eventually thin out the rotors, reduce their thickness, and shorten their durability and lifespan. Rather than resurfacing more than twice, replacing the rotors will be better to ensure proper sync with the brake pads.

Is A DIY Warped Rotor Replacement Procedure Possible?

Without playing the ostrich, I’ll say yes. It is possible but not advisable. You can achieve relative success in a Do-It-Yourself replacement of the warped brake rotors of your car.

As a matter of fact, a lot of auto repairs and fixes can be undertaken by car owners and drivers. However, this will require basic technical know-how, mechanisms, as well as the tools needed for the fix.

However, when it comes to the braking system, car operators must take caution. You’ll need a lot of money to fix it if anything more problematic goes wrong while replacing the brake rotors.

For instance, if you fail in installing the rotor or aligning the brake pads or calipers correctly, there’s no doubt that the brakes will fail, and it can lead to catastrophic consequences.

Hence, I won’t advise that you replace the rotors yourself with or without the experience of driving a car or fixing a few issues. While some experienced car operators can dare it, the best bet is to approach a certified and professional technician to handle repairs that bother on the entire braking system of your car.

Resurfacing Vs. Replacing Warped Rotors: Which Is Better?

If you ask me, the better bet between resurfacing and replacement is the latter. Resurfacing warped brake rotors is an easier and natural option to take when placed side by side with buying new rotors.

Additionally, the resurfacing option comes cheaper and saves you money.
However, there are drawbacks to opting for resurfacing over replacement.

Some of the issues you’re likely to face with resurfacing warped rotors include:

  • Low Density: When you resurface your brake rotors, chances are that they will not be as thick as they should be. By design, the rotors are to be dense and thick enough to withstand the contact and gliding coming from the brake pads.
  • Reduced Lifespan: Another downside of resurfaced rotors is the shortening of the component’s life. Normally, resurfacing yanks off some material from the rotor, making it vulnerable to poor performance. Hence, its life becomes short.
  • Anti-Absorption Capacity: Naturally, the rotor is designed to resist or absorb a lot of heat generated by the sliding with the brake pads and brake calipers.

Going for brand new brake rotors offers a lot of advantages. Although they may come pretty expensive, – and I think the cost of the entire braking system doesn’t come on the cheap – new rotors offer durability, extended lifespan, great brake performance, and more.

In the long run, you’ll save more money than budgeting on resurfacing over and over again.

A lot also depends on how much you can spare. Valuating the cost of replacing or repairing your car brake rotors depends on the severity of wear and tear, the price from the part seller, the model of the car, and labor cost.

By implication, there’s no fixed cost. However, on average, you can spend about $250 for resurfacing while a complete replacement can cost about $600 or more.

Final Thoughts

In the end, what causes brake rotors to warp are not things out of this world. They’re mechanical issues that you can relate with in real-time and quickly nip in the bud.

For instance, it takes a pretty cautious driver or car owner to observe the metal-metal gliding of brake pads against the brake rotors, the pad overheating, the physical damage, wrong pad or caliper alignment, and more. Do not wait until your rotors become warped before acting; it won’t serve you any good in the end.