Why is it important to bleed the brakes after replacing brake components?

Bleeding the brakes is a vital process after replacing brake components, primarily to remove air from the brake lines. Air can introduce compressibility into the brake system, which diminishes braking performance and can lead to a spongy or unresponsive brake pedal. When air is present in the hydraulic brake fluid, it compromises the system's ability to transmit pressure effectively from the brake pedal to the brake calipers, thereby preventing the brakes from functioning optimally.

By bleeding the brakes, technicians ensure that only brake fluid, which is incompressible, remains in the lines. This step is essential to restore proper hydraulic pressure and ensure that the brakes respond reliably when needed, enhancing both safety and performance while driving.