Is It Normal for Car Brake Discs to Rust?

[StSpencer]

For most household cars, brake disc rust is a very normal phenomenon and is not a criterion for checking whether the car is new or not. Whether the brakes are prone to rust mainly depends on the material of the brake discs, as most household cars currently use gray cast iron 250 standard brake discs. Although they provide good braking performance, they have a high carbon content and no rust protection on the surface, making rust inevitable. Below is relevant information about car brake disc rust: 1. Reasons for rust: Brake discs are exposed to the elements, constantly in contact with mud, rainwater, and moisture in the air. If the car is not driven for a few days, the brake discs will start to rust. Even newly replaced brake discs can rust overnight in humid weather. General rust does not affect braking performance. In fact, simply driving the car out and applying the brakes a few times can remove the rust. 2. How to deal with rust: If the car is left unused for a long time and the brake discs are severely rusted, cleaning is necessary. This is because car braking relies on the friction between the brake pads and the brake discs. If the rust on the brake disc surface is too thick, it will not provide effective braking, inevitably extending the braking distance. Moreover, friction between the brake pads and rust is unstable, often causing brake pedal vibration, producing harsh noises, and accelerating wear on the brake pads.