Why Do Brake Discs Turn Yellow?
2 Answers
Turning yellow is a normal phenomenon and has no impact on the vehicle or braking performance. Since brake discs are made of steel and lack anti-rust protection due to frequent friction, rust can appear after being parked in humid weather for a few days or exposed to rain. Even new cars at 4S dealerships may experience this if left outdoors for an extended period. It is important to emphasize that rust on brake discs does not affect braking performance, and you can drive with confidence. For more information on rust removal: 1. Braking: Drive the car out and apply the brakes several times to wear off the rust on the brake disc. 2. Sanding: If some rust remains, you can remove the steel wheel and sand it off with sandpaper.
I also noticed my car's brake discs turning yellow recently, which is actually quite common. It's mainly due to the oxidation of the iron surface of the brake discs in humid environments, forming a layer of yellow rust—especially after rain or when the car isn't dried thoroughly after washing. No need to worry too much, as this doesn't affect braking performance; driving out and braking a few times will wear off the rust. However, if the yellow spots are deep or there are cracks, it might indicate excessive brake disc wear or residue from brake pad materials, which could increase the risk of unusual noises. I usually make sure to keep the vehicle dry and park under a shelter to minimize rain exposure, which helps prevent yellowing. Maintenance tip: Inspect the braking system monthly, and replace worn parts promptly—don't skimp on safety.