I have a Honda Civic Coupe 2006 with ~158,000 miles. I changed the rotors and break pads on all 4 wheels about 2 months ago. Yesterday I decided to change the break fluid. Started off with bleeding the brakes and putting the new fluid. It was fine except for the fact it looked like there was a lot of air in the hose when I was bleeding the breaks.
After that, during a test drive it was all fine. But later, when I was driving and braking at a moderate-low speed I started hearing this clicking/knocking type sound.
Now if I haven't changed the brake pads and rotors prior to that, I would've assumed it's a potential issue with them. But since I changed them 2 months ago and had no issues, it's probably something else.