I recently had new brake pads installed both front and rear, plus had the brake fluid flushed. Now I notice a single initial click or knock when applying the brakes. If I push on the brakes a second or third time it is quiet. The next time I need to brake there it is again, one click/knock. It doesn't happen when still, only moving. The sound is coming from the front on the driver's side. Anyone with an idea of what this sound could be? Thanks in advance!

 

Is it there when you acclereate. By best guess based on your description is that when/if the hub was reinstalled/adjusted the bolt that holds the hub inokace was overtightened. I know someone who hears a click with every front to back weight shift on the car (so accel and braking).