What Causes the Clicking Sound When Starting and Braking?
2 Answers
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 noises. Solution: Release the brake more quickly. 2. Rust adhesion between the brake disc and brake pads: This 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, causing abnormal noises when starting the car again. Solution: Apply lubricating oil or specialized lubricant at the connection between the brake pads and brake calipers at a repair shop to resolve the issue. 3. Excessive metal fibers in the brake pads: Sometimes, metal particles may form, producing a harsh sound when pressing or releasing the brake. This condition typically disappears after driving for a while. Solution: If the problem persists, it may be due to poor manufacturing quality. It is recommended to replace the brake pads promptly to avoid scratching the brake disc.
Last time I drove my old Passat, I encountered the same situation - a clunking sound when releasing the brake on cold start. After some investigation, I found it was caused by the brake discs and pads sticking together, especially noticeable after parking in rainy weather for extended periods. Try parking without the handbrake engaged, just put it in P gear and use bricks as wheel chocks. If the sound disappears the next day, then that's the issue. However, pay attention to the brake caliper pins - my neighbor's car had clunking sounds caused by seized pins leading to uneven brake pad wear. Additionally, worn transmission mounts can also cause braking sounds during start-up and gear shifts, producing a dull noise. For vehicles with auto-hold function, the sound of the release mechanism activating at the moment of start-up can easily be misdiagnosed. Anyway, rule out minor issues first. If accompanied by brake pedal pulsation or steering wheel vibration, you should immediately check the drive shaft.
