I've recently noticed that during fairly hard braking (not ABS kicking in hard braking, but just a little harder that you normally would) car is producing two distinct metallic clicks that I can feel (sort of) in the in the break pedal. It seems to do that after driving the car for some time (at least 15min or so). Gentle breaking produces no foreign sounds. I've removed the tires, took the pads off, cleaned and lubricated pins, inspected rototrs- all seems to check out fine (although, I believe rotors are warped as there's a bit of pedal pulsation when breaking from highway speeds). All suspension components appear to be in a good shape. Any idea what could be the root cause? Any one else had the same issues perhaps?