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The Ultimate Brake Dust Guide: Causes, Cleaning, Prevention

May 12, 2021

Brake dust is a type of residue that builds up on your wheels over time.

And while it’s a natural byproduct of the braking process, there are ways to reduce it and remove it from your wheels.

But what exactly is brake dust?

And how do you clean it?

In this article, we’ll tackle what brake dust is, why you should clean it, and how to prevent it.

This Article Contains

Let’s get started.

What’s Brake Dust?

Brake dust is a dark residue that collects on your wheels. It’s a combination of iron particles, carbon residue, and friction material that makes your wheel look like it’s saturated with road grime. 

The color of this dust depends on the pad material in your brakes. 

For example, most European cars usually have very dark brake dust, produced by brake pad materials that prioritize quietness and performance. Other brake pad materials may have higher metal particles for increased longevity and produce reddish dust.  

It’s important to note that a buildup of these metallic particles is unavoidable, irrespective of the type of braking system your car has — whether it be a disc brake setup or drum brakes. 

But why is it unavoidable?

What causes it in the first place?

What Creates Brake Dust? 

When you depress the brake pedal, one of two things happen:

Your brake pads clamp onto the brake rotor (in a disc brake), or your brake shoes push against the brake drum (in drum brakes). These clamping or pushing motions create friction, which in turn, stops your vehicle wheels.

However, this friction also creates brake debris that builds up over time. 

Disc brakes are the worst offenders when it comes to brake dust grime. 

Their open design means brake dust collects directly (and visibly) on the wheel. If your car uses alloy wheels, the dark brake dust will be very visible and contrast clearly against the wheel hub. 

Drum brakes are enclosed, so the brake drum contains most of the brake dust buildup. This means that aesthetically, you won’t face as big an issue. However, it does mean that your drum needs to be cleaned of excessive brake dust periodically. 

But all this is just dust, right?

How big a deal is this?

Why Is Cleaning Brake Dust Important?

The modern brake pad typically contains some amount of metallic fibers to aid with friction. 

When your brakes generate brake dust, these metal particles end up on the wheel, the brake caliper or brake drum, and other nearby suspension components to cause a variety of problems.

Here’s why you wouldn’t want to leave brake dust on your wheels for too long:

1. It Can Damage Alloy Wheels 

Metallic brake dust is a caustic and abrasive material. 

If left uncleaned, it can etch into the protective coating on an alloy wheel, making the wheel vulnerable to corrosion and cause permanent damage. 

2. It Can Affect Braking Performance

A small amount of brake dust on your wheel is normal. 

But excessive brake dust can reduce braking performance and cause brake noise.

Brake dust can also collect on the brake caliper and brake rotor, creating an uneven surface for braking, resulting in vibration and noise. This condition is even more prevalent in drum brakes when brake dust gets trapped inside. 

If you notice large amounts of brake dust on a wheel or notice brake noise, get a mechanic to review your brake system, as it can indicate a more serious issue — like worn springs in a brake drum or problems with the brake pad and rotor installation. 

Okay, so brake dust is more serious than it seems.

How do you remove it? 

How Do I Clean Brake Dust?

Cleaning off brake dust is not difficult, but regular car wash supplies might not give you spotlessly clean wheels if you’ve had brake dust piling up for a long time. 

In those cases, you’ll probably need an appropriate wheel cleaner.

Make sure you get the correct type of wheel cleaner as different wheels have different coatings and finishes. Don’t use harsh chemicals, as while these can remove dirt, they may also damage the protective coating on your wheels. 

Here’s what you need to do to clean brake dust buildup:

Getting your wheels professionally cleaned is always a good idea, but is there a way to prevent you from getting to that stage?

What Can I Do To Prevent Brake Dust?

Your brakes will always generate brake dust, but there are several things you can do to keep it from accumulating

1. Use A Brake Dust Repellent

You can try out an aerosol brake dust repellent that is sprayed onto your rims. This forms an invisible, protective barrier that repels brake dust and lasts for a few weeks. 

Keep in mind that it may not work on all types of alloy wheels. 

2. Mount A Brake Dust Shield 

A brake dust shield is another way to curb brake dust accumulation on disc brakes. These aluminum plates are mounted between the wheel rim and brake rotor, and are designed to catch brake dust so that it doesn’t settle on the rims. 

However, some drivers may find an excessive heat buildup in their front brakes as a result of this, which can affect brake performance. The dust shield also makes the wheel look less appealing if aesthetics are a concern.

3. Apply An Advanced Finishing

You can consider layering on an advance finishing on the wheels, like a ceramic coating, to create a protective barrier that repels brake dust and other road contaminants. 

These wheel coatings tend to be permanent or semi-permanent and are easier to clean. They’re often applicable to other car surfaces to help combat road grime, too. However, they’re also more expensive than a regular brake dust repellent and may need to be applied by a professional.

4. Change To Ceramic Brake Pads

Ceramic brake pads produce very little brake dust, are quieter, and last longer than semi-metallic brake pads. The few drawbacks are that they’re more expensive than a semi-metallic brake pad, and they’re not suited to performance vehicles. 

If you’re not sure what type of brake pad suits your vehicle, you can always consult a mechanic for advice.

Closing Thoughts

Cleaning brake dust off your wheels helps preserve how it looks and ensures its long-term durability. However, keep in mind that excessive brake dust can be indicative of not only brake wear but other more serious issues. 

If you’re concerned, you can always count on RepairSmith to lend a hand with any brake system problems.

Why RepairSmith?

RepairSmith’s ASE-certified technicians can perform all types of repairs and replacements right in your driveway. Booking an appointment online is easy, and all repairs come with a 12-month, 12,000-mile warranty.

For an accurate estimate of how much a brake repair or maintenance will cost, just fill out this online form.