Noise when brakes are applied

toyota
rav4

#1

I have a front wheel drive 07 Rav4. When I apply the brakes there will occassionally be a clunk. It is a single noise and not a vibration, grinding, or squealing. You can feel it in both the drivers side and passengers side floor board. I have had it to my mechanic and to the dealer, but we can’t get it to reproduce the noise. It happens every day,but not at a consistent speed or anything where I can make it happen. HELP!! Any ideas??