Why does the parking brake use a mechanical linkage instead of a fluid linkage?

The parking brake uses a mechanical linkage instead of a fluid linkage primarily for reliability and simplicity. Mechanical linkages provide a direct connection between the brake lever and the brake mechanism, ensuring immediate response and consistent performance without the risk of fluid leaks or pressure loss. Additionally, mechanical systems are easier to diagnose and repair, making them more practical for a safety-critical system like the parking brake.