What would indicate that the bleeding procedure of a hydraulic brake system has been completed?

The completion of the bleeding procedure in a hydraulic brake system is indicated by the fluid escaping at the wheel cylinder running clear. This means that any air that was present in the brake line has been purged, and only clean brake fluid is now flowing from the system. Air trapped in the brake lines can lead to a spongy or ineffective brake pedal, as air compresses more readily than fluid, which can cause reduced braking performance. Therefore, when the fluid running out is clear, it demonstrates that the system is free from air bubbles and contaminants, ensuring optimal brake function.

While other options may suggest specific attributes of a brake system, such as the height of the brake pedal or a solid feel to the pedal after pumping, those factors could also be influenced by other issues unrelated to proper bleeding. The critical confirmation that the bleeding process is successful is the observation of clear fluid being expelled, which provides direct evidence of air removal from the hydraulic system.