What Causes the Loud Noise When Releasing the Brake During Car Startup?

[Claudia]

The reasons for the loud noise when releasing the brake during car startup are as follows: 1. Releasing the brake too slowly when starting. When the brake pedal is released gradually, the engine already has sufficient power to propel the car forward, but the brake hasn't been fully released yet. As a result, the moving wheels are restrained by the brake system, naturally causing abnormal noise. 2. The brake disc and brake pads are stuck together due to rust, causing abnormal noise. This situation usually occurs after driving in rainy weather and then leaving the car unused for several days. The brake disc and brake pads rust and stick together, resulting in noise when starting the car again. 3. The semi-metallic material of the brake pads. Brake pads contain a large amount of metal fibers, which can sometimes form metal particles. These particles produce a harsh noise when pressing or releasing the brake. This noise typically disappears after driving for a while. If it persists, it may indicate poor manufacturing quality, and it is advisable to replace the brake pads promptly to avoid scratching the brake disc.

[DiEllie]

I've encountered the issue of loud noises when starting the car and releasing the brake. A common cause is rust on the brake disc surface, especially noticeable during humid rainy days or after prolonged parking. Rainwater or dew seeping in causes metal oxidation and rust. When you release the brake pedal, the brake pads rubbing against the rusted disc produce a screeching noise. This is usually not a major issue, as driving a short distance to clean off the rust through friction will eliminate the noise. However, if it occurs frequently, it might indicate uneven wear of the brake pads, debris stuck in them, or loose suspension components amplifying the noise through vibration. It's advisable to park in dry, well-ventilated areas, avoid waterlogged zones, or regularly inspect and maintain the brake discs to remove rust, ensuring a more secure driving experience.

[LailaLee]

My car sometimes makes a loud rumbling noise when starting and releasing the brake. At first, it scared me into thinking the car was broken. Later, fellow car enthusiasts told me it's mostly due to severely rusted brake discs or stuck brake pads, which occurs more often on winter mornings or after rain. Actually, this noise comes from the sudden release of friction. It usually quiets down after driving a few hundred meters to wear off the rust. However, if it happens every time or is accompanied by vibrations, you should check the brake system for debris or worn suspension to prevent unsafe driving. I've developed a habit of lightly pressing the brake pedal a few times to warm it up before driving in the morning, avoiding the sticking noise. In short, don't worry too much—most cases are minor issues. But remember to keep your tires dry and clean.

[DaniellaFitz]

A loud noise when releasing the brake during car startup is mostly caused by rust or sticking on the brake discs, as metal easily oxidizes and creates friction noise after rain. Sometimes, aged brake pads can cause excessive separation due to sticking. This temporarily interferes but isn't a malfunction; if the noise disappears after short-distance driving, it's normal. If the loud noise persists with vibration, it indicates component damage, requiring prompt inspection of brake discs or suspension to avoid brake failure risks. Regular wheel hub rinsing can prevent rust.