How do you effectively bleed air from a brake system?

To effectively bleed air from a brake system, the correct method involves pumping the brake pedal with the bleeder valve open. This process works by allowing brake fluid to flow from the master cylinder through the brake lines and out of the brake caliper or wheel cylinder while simultaneously forcing air bubbles trapped in the system out through the open bleeder valve.

When the brake pedal is pressed, it creates pressure in the brake system, pushing the hydraulic fluid, along with any trapped air, towards the bleeder valve. Opening the valve releases both the brake fluid and the air, ensuring that the system is properly purged of air pockets that could cause a spongy brake feel or reduce braking effectiveness.

In contrast, simply replacing the brake fluid entirely does not guarantee that all the air will be removed from the system, as air can still reside in various parts of the brake lines. Driving the vehicle in reverse does not address the issue of trapped air and is not a method used in brake bleeding. Adding air to the brake lines is counterproductive, as it would introduce air into the system rather than removing it, which can compromise brake performance.