Knocking sound when applying brakes
 

Hi Guys,

Every morning when I start driving my 2009 Sonata, I hear a knocking sound when I apply the brakes. This happens for the first 10-15 km after which, it disappears.

I had my brakes pad and rotors changed few weeks ago but I have this sound for the last one year

Any idea what could be the problem?

knocking sound when applying brakes
 

had that flapping valve sound when i applied brakes with my 2001 lumina.
my son in law says it was the abs system needing diagnostic work.
my mechanic had said there was no safety risk, but that i should see his brake man. I sold that car for another reason, yet i should have found out just to know. good luck!

I've same problem with 2011 Sonata Limited from day 1. I keep telling this to the dealer, but dealer service dept unable to fix this at. I brought the vehicle to the dealer almost 1-2 times per month til now (almost 15 times)

The brake works without any sound up to 2-3 days after each service or maintenance. Also this is related to the ABS.

Recently I met with an accident (since i unable to come to full stop under 35MPH) and the Collision center repair adviser told me that I should consult the dealer or 3rd party service dept to evaluate or diagnose the ABS.

Any further information regarding ABS or this kind of brake sound issues from senior members would be appreciated.