What is the Principle of Automotive Braking Systems?
3 Answers
Automotive braking system principle: It utilizes mutual friction between non-rotating components connected to the vehicle body and rotating components connected to the wheels to prevent wheel rotation or its tendency, converting the kinetic energy of the moving vehicle into heat energy dissipated into the atmosphere. Wheel brakes mainly consist of rotating parts, fixed parts, and actuating mechanisms. Currently, automotive braking systems are generally divided into two types: hydraulic braking and pneumatic braking. Hydraulic braking uses the master cylinder to transmit brake fluid as the medium through brake lines to each wheel cylinder, achieving the braking effect. Pneumatic braking employs high-pressure gas as the braking medium, delivered through pipelines to each wheel cylinder to achieve braking.
When I first started learning car repair, I studied the braking system. Simply put, it uses friction to stop the car. When you press the brake pedal, the push rod moves the piston in the master cylinder, forcing brake fluid to the wheel cylinders at each wheel. The wheel cylinder pistons then push the brake pads to clamp the rotating brake discs, slowing the wheels. The whole process is like squeezing bicycle brakes, but with hydraulics to amplify the force. During friction, kinetic energy turns into heat and dissipates, which is why brake discs get hot after aggressive driving. Modern cars also have ABS (Anti-lock Braking System), which uses sensors to monitor wheel speed. If a wheel is about to lock up, ABS automatically adjusts brake pressure to prevent skidding. Regularly changing brake fluid is crucial because water contamination can affect hydraulic performance.
I've driven old trucks for years, and the braking principle is actually quite simple. The driver steps on the pedal to generate force, which is amplified and transmitted to the wheels through the hydraulic system. Key components include the master cylinder, wheel cylinders, and brake lines. The master cylinder acts like a large syringe—when pressed, it pushes brake fluid to all four wheels. Since fluid is incompressible, force transmission is rapid. Modern cars mostly use disc brakes, where two brake pads clamp onto a rotating brake disc. Heavy vehicles often employ drum brakes at the rear, where brake shoes expand to create friction against the brake drum. Regardless of type, the core principle remains friction-based deceleration. Maintenance involves checking brake pad thickness and ensuring no fluid leaks from the lines, otherwise braking may become soft or even fail.
