Insufficient information. How many miles on car, how old, what year car? It could be many things. If you aren't able or willing to pull the wheels and investigate, look up a reputable mechanic.
Try rotating your tires. Put the fronts on back and backs on front. Could be a bad tire.Thank you for your reply.
I forgot to mention that these vibration occurs not only during brake, sometimes but not often it occurs when I drive steep uphill. Vibrating starts Just the beginning of the climb and continues about 8-10 seconds.
Today I changed all four tires with new one, but now I doubt my problem is only related to the brakes because the same vibration was observed when going uphill without pushing brake pedal. I can't explain well but it feels like something jumping in front driveshaftTry rotating your tires. Put the fronts on back and backs on front. Could be a bad tire.
I don't notice anything suspicious or wrong, all rotors looks quite well, brake pads also not, the pads were not burnt.When you had the tires off did you look or feel for anything wrong with brakes, suspension or drivetrain? How did the rotors look?