I bought my 2001 A4 1.8t about a month ago and its been great. Recently however I have noticed a popping sort of sound when i apply them quickly. It doesn't make the sound when i gently apply them. A friend of my mentioned it might just be break dust. The breaks seem to work just fine, its just that they make this noise. I bought the car used and it has about 58000 miles on it. Could it also be I just need to change the break fluid, I know that it needs to be changed every two years and i don't know the last time it was changed. Any advice would be much appreciated.

 

Have you taken the wheels off and looked at the brakes?
Do the pads look ok?
Do they feel real loose? meaning can you easily move them in the caliper.

 

You should have the brakes inspected. Could be the brake pad seperating from the metal backing.