Why does the brake feel spongy?

[OEvan]

There are many reasons for spongy brakes, including excessive wear of brake pads, lack of brake fluid, or blockage of brake lines. When a car experiences spongy brakes while driving, it is essential to stop and inspect promptly to prevent potential safety hazards during operation. Braking, also known as deceleration, refers to the action of stopping or reducing the speed of moving locomotives, vehicles, and other transportation 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.