Today I will show you the easiest way to DIY a brake fluid flush on a 2018 Audi S4/S5 B9. The power brake bleeding method is by far the quickest, least messy and most sure way to flush your brakes. Per the Audi maintenance schedule brakes should be flushed every 20,000 miles or 2 years. While this may seem like a frequent interval fresh fluid and elimination of air in brake lines is essential to optimal braking performance.