Why is brake fluid hygroscopic To prevent rust in the brake system. To prevent local freezing in the brake system. To keep the brake fluid viscosity as high as possible. Brake pedal feel is improved if there's a little water in the brake system.

Brake fluid is hygroscopic, meaning it has the ability to absorb moisture from the air. The primary reason for this is to prevent rust in the brake system. When moisture is absorbed by the brake fluid, it forms a protective layer on the metal surfaces within the brake system, preventing direct contact between the metal parts and thus preventing rust from forming. This helps maintain the integrity and performance of the brake system over time.