What is the primary purpose of bleeding a brake system?

The primary purpose of bleeding a brake system is to remove air from the brake lines. When air enters the brake lines, it can create compressibility in the brake fluid, leading to a spongy brake pedal feel and reduced braking efficiency. In hydraulic brake systems, it’s crucial to maintain a solid column of fluid for effective brake operation. Bleeding the brakes involves releasing the trapped air to ensure that the brake fluid can exert consistent pressure on the brake components, allowing for proper braking performance.

While replacing brake fluid is also a part of maintenance and can be an associated benefit of bleeding the brakes, the main focus of the bleeding process itself is to eliminate any air. Cleaning brake components and checking brake pad wear are important maintenance tasks, but they do not relate directly to the bleeding process. Thus, the act of bleeding specifically targets air removal to ensure optimal brake function.