Why does the car make noise when braking at the beginning?
2 Answers
There are two main reasons why a car makes noise when braking at the beginning: 1. Hard spots on the brake disc: This is caused by harder material during manufacturing, and the noise will disappear after the brake pads wear down these spots; 2. Severe wear of the brake disc and pads, resulting in metal-to-metal contact, which also produces noticeable noise. Solutions: 1. For hard spots, a simple method is to drive in reverse at about 5 km/h and apply the brakes a few times to remove the hard spots. If the noise is not too loud, it can usually be ignored as it does not affect driving; 2. If it is metal-to-metal contact, the brake disc and pads should be replaced immediately. Additionally, if the brake warning light on the dashboard is not activated, the sensor connected to the brake warning light should also be checked for any issues.
I find it quite common for cars to make noise when braking right after starting, such as when the disc brake rotors develop a thin layer of rust, especially after rainy days or prolonged inactivity, causing a sharp squealing sound when driving in the morning. Another reason is the accumulation of dust or sand on the brake pads, which can produce a squeaking noise during friction. Newly installed brake pads often behave this way initially, requiring a week or so of breaking in to quiet down. This isn't a major issue as long as the noise stops after a few instances. However, if the noise persists or is accompanied by unstable braking, it might indicate loose calipers or debris stuck in the system, necessitating an immediate visit to the auto shop. I often encounter this with my older car, particularly in winter when metal contracts in the cold, making it more prone to noise, but it usually resolves after the car warms up.
