What is the Problem with Rusty Brake Pads?

[AaronFitz]

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.

[DiKing]

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.

[AdrianLee]

Old Zhang, who has been repairing cars for twenty years, says there's no need to panic if the brake pads rust. These gray cast iron pads inevitably rust when exposed to moisture, just like a newly bought kitchen knife will develop rust spots if left unused. The key lies in the location of the rust: surface rust will wear off after a couple of brake applications, but rust on the fixed pins or caliper slide rails can easily cause jamming. He suggests pressing the brakes a few more times after washing the car to drain water, and warns that in snowy winter regions, the most dangerous thing is the mixture of snow and salt, which can double the rusting speed. Last month, a water-damaged car came in for repairs, with the brake pads and iron frame rusted together—that's when real trouble arises. Ordinary thin rust doesn't require part replacement, and Old Zhang always advises us not to waste money.

[Norah]

Last week while washing my car, I noticed reddish-brown rust spots on the wheel hubs and thought the car was totaled. The mechanic laughed and said every car gets this - it's like nails rusting in rain when metallic brake pads meet moisture. What really matters is the brake pad material; today's semi-metallic formulas resist rust better than pure ceramic ones. He had a test car left outdoors for three rainy days - it creaked for three brake applications before functioning perfectly. The real concern is coastal areas with salty sea breeze, where long-term parking may corrode caliper guide pins. The mechanic taught me a trick: during rainy seasons, park in P gear without engaging the handbrake to keep brake pads suspended away from moisture. Now I stay calm seeing rust marks - what truly warrants alert is when brake discs become mirror-smooth from wear.