Why Does the Car Make a Squeaking Sound When Braking?
2 Answers
It is normal for a car to make noise when the brakes are applied, as the brake pads and brake discs rub against each other, causing sound. Below is an introduction to car braking: Brake System Introduction: Braking, also known as stopping, refers to the action of halting or reducing the speed of moving locomotives, vehicles, and other transport tools or machinery. The general principle of braking involves fixing a wheel or disc on the high-speed shaft of the machine and installing corresponding brake shoes, bands, or discs on the machine base, which generate braking torque under external force. Purpose of Braking: The goal is to decelerate, reducing speed or bringing the vehicle to a stop. The principle of braking is to convert the kinetic energy of the car into heat energy, which is then dissipated. The kinetic energy comes from the power provided by the engine, which requires fuel combustion to generate work. Drum Brakes: Two semi-circular brake shoes are installed inside the wheel, and the "lever principle" is used to push the brake shoes into contact with the inner surface of the brake drum, creating friction. Drum brakes utilize stationary brake shoes inside the brake drum to rub against the rotating drum, generating friction to reduce the wheel's rotation speed. When the brake pedal is pressed, the force from the foot causes the piston in the master cylinder to push brake fluid forward, creating pressure in the hydraulic circuit. This pressure is transmitted via brake fluid to the wheel cylinders at each wheel, where the pistons push the brake shoes outward, causing them to rub against the inner surface of the brake drum. This generates sufficient friction to reduce the wheel's rotation speed, achieving the braking effect.
When I first started learning to drive, I would hear a squealing sound every time I stepped on the brakes, which made me quite nervous. Later, I learned that this could be because the brake pads were almost worn out, causing the metal layer inside to rub directly against the brake disc. Another common reason is rust on the brake discs during rainy days—when the rusted parts come into contact with the brake pads, it produces noise. Alternatively, sand, dust, or small stones stuck in the braking system can also make the friction louder. Newly replaced brake pads also need a break-in period and may not be completely quiet at first. Never ignore this sound—it signals potential safety hazards. I must remind everyone to regularly check the brake pad thickness and clean the system at a shop. Safety comes first!
