What causes the clunking sound when the car starts moving?

1 Answers
OSadie
07/29/25 9:44pm
The clunking sound when the car starts moving is caused by friction between the brake pads and brake discs, which is normal and nothing for the owner to worry about. The vehicle's braking system consists of the master cylinder, vacuum booster, wheel cylinder, brake pads, and brake discs. When the brake pedal is pressed, the brake pads clamp onto the brake discs, converting kinetic energy into heat energy to slow down the car. The vacuum booster provides assistance when the brake pedal is pressed, making it easier for the driver to apply the brakes. Upon opening the engine hood, a black metal disc can be seen below the windshield on the driver's side - this is the vacuum booster. In front of the vacuum booster is the master cylinder, which has a reservoir for holding brake fluid.
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