In a normally operating brake system, the master cylinder secondary piston is activated by ________

The activation of the master cylinder secondary piston in a normally operating brake system occurs due to the fluid pressure generated between the primary and secondary pistons. When the brake pedal is pressed, the primary piston moves forward, creating hydraulic pressure in the brake lines. This pressure is then transmitted to the fluid inside the master cylinder, causing the secondary piston to activate. This design ensures that both pistons work in synchronization, contributing to the overall effectiveness of the brake system.

The hydraulic pressure is crucial because it allows for the efficient transfer of force from the brake pedal to the brake components, ensuring that the vehicle can stop effectively. The secondary piston plays a vital role in maintaining consistent brake pressure and enhancing braking performance. This hydraulic system's efficient operation is why fluid pressure is integral to the process of braking in modern vehicles.