How do you flush a brake system?

To flush a brake system, start by lifting the vehicle and removing the wheels for access to the brake calipers. Use a brake bleeder kit or a vacuum pump to remove old brake fluid from the master cylinder, then refill it with fresh fluid. Begin at the brake furthest from the master cylinder and have an assistant pump the brake pedal while you open the bleeder valve to release old fluid and air until new fluid flows out. Repeat this process for each brake, ensuring the master cylinder remains filled throughout to avoid introducing air into the system.