When I apply brake, there is a sound under the body.. sound is like 'cling..' I think some nuts are lose.. anybody have had same problem as me?
Thanks. Also, my car is A4 1.8 quattro 2002. Thanks again.

 

front or rear. right or left. you gotta isolate the problem.
raise the car and spin the wheels while someone else presses the brake.
you watch to see if anything is out of ordinary. pads being loose, caliper
moving more around.

 

Did you replace your brake pads recently... I had some pads in my car for a bit and they made a clink cuz they were moving in the carriers.