Understanding Brake Dust & What Causes It

Brake dust can be a real nuisance, especially for motorists who like to keep their rims looking clean and shiny. But apart from detracting from a vehicle’s appearance, excessive brake dust can cause more serious issues.

What is brake dust? 

Simply explained, brake dust is the combination of friction material from brake pads as well as the iron particles from the surface of the rotors, that are shed during the heat build-up and friction developed through braking applications. These microscopic particles accumulate over time, presenting as a dark-coloured film on rims as well as calipers and other braking and suspension components.

Along with resulting in unsightly dirty and dull rims (which can take considerable elbow grease to clean), brake dust can cause other problems. Metallic brake dust is corrosive in nature and can etch into the surface of the rim – especially alloy wheels – causing damage. Brake dust can potentially also discolour tyres.

Accumulation of brake dust on rotors and inside brake drums may also lead to braking performance issues, as the build-up can cause uneven braking surfaces which may result in vibration and noise.  

Excessive brake dust could be a sign that there is an issue with the braking system. Sticking calipers or sliding pins can result in brake drag, which happens when the pads don’t properly retract after the brake pedal has been released, and this causes more brake dust than normal.

Tips for reducing brake dust on your car

Choosing the right brake pads makes a big difference when trying to minimise brake dust. Friction material manufacturers such as Bendix invest heavily in developing and testing dust-reducing compounds in their brake pads. Through its specially selected compounds, Bendix ceramic pads including General CT, 4WD/SUV, Ultimate 4WD Ultimate+ and Euro+ ranges, offer superior low dust performance.

A regularly maintained braking system will also help reduce excessive dust by identifying any potential issues such as dragging brakes as early as possible, allowing them to be promptly fixed.

For motorists concerned about the aesthetics of dirty rims, ceramic wheel coatings are a further option. Available from leading automotive outlets, once applied to rims, these coatings offer a protective barrier that helps repel brake dust and road impurities.