Final answer:
Hydraulic brakes usually fail due to leaks in the system or air in the hydraulic fluid, as both disrupt the transmission of pressure dictated by Pascal's principle. Regular maintenance is essential to prevent such failures. Manufacturers can be held liable for known defects leading to brake failures.
Step-by-step explanation:
The two main reasons hydraulic brakes fail are typically either due to leaks in the brake system or air getting into the hydraulic fluid. In a properly functioning hydraulic brake system, Pascal's principle ensures that pressure is transmitted undiminished in every direction and applies equal force to equal areas. Thus, when a driver exerts force onto the brake pedal, it is increased through a simple lever and further amplified by the hydraulic system. Each wheel cylinder receives this same pressure, creating an equal force output, which allows for the vehicle to decelerate uniformly.
However, if there is a leak, the hydraulic fluid necessary to transmit the pressure can be lost, consequently reducing the system's ability to create the necessary braking force. Similarly, if air enters the system, it can compress, unlike the hydraulic fluid, which disrupts the consistent transmission of pressure and diminishes braking efficiency. Regular maintenance of the braking system, including checking for leaks and ensuring there is no air in the hydraulic lines, is essential to prevent brake failure.
A counter example highlights the consequences of neglecting such maintenance. If a manufacturer is aware of defects in the brake system of an automobile but still decides to proceed with production and sale, resulting in accidents, the manufacturer can be held liable for any resulting injuries and deaths.