What is the Problem with Rusty Brake Pads?
2 Answers
Rusty brake pads are a normal occurrence, primarily caused by the material of the brake pads, but this does not affect the safety or normal operation of the vehicle and does not cause any issues. If the rust on the brake disc is minimal, it does not require special treatment; if the rust is more severe, it may cause vibrations or shaking during braking, such as brake pad vibration, steering wheel shaking, or body vibration. In such cases, the brake pads need to be replaced. Most car brake pads are made of cast iron. Long-term exposure to rain, snow, and harsh environments inevitably leads to surface rust. If the rust is minor, it can be worn away through regular braking. Additionally, friction between the brake pads and the brake disc can also remove rust after several braking cycles, restoring normal use. If the brake pads are severely rusted, the surface becomes uneven, causing shaking, increased wear, or scratches, which can affect the vehicle's braking performance and driving safety. In such cases, it is best to take the vehicle to a repair shop. The brake disc should be removed, and the rust should be cleaned off with sandpaper. After proper installation, a road test should be conducted to ensure there are no abnormalities in braking. It is important to note that sanding should not be too forceful or done too frequently, as this can thin the brake disc, affecting its performance and lifespan.
Last time I parked my car at the riverside garage for a week, and when I picked it up, I noticed patches of rust on the brake pads. I immediately called the mechanic, Lao Wang. He told me that cast iron brake pads are indeed prone to rust, especially during the rainy season in the south. Lao Wang explained that the rust layer is actually very thin and would wear off automatically after stepping on the brakes a few times when starting the vehicle. This surface rust doesn’t affect braking performance at all; in fact, brake pads washed by rain have better friction. However, he also reminded me that if the car is left parked outdoors for three months without moving, the rust could harden and potentially scratch the brake discs, which would then require a thorough inspection. Now, I don’t cover my car with a car cover during rainy days anymore—letting the brake system ventilate naturally actually helps prevent rust.
