Volvo: front brake vibration/pulsation, pulsation, rotors

Question
Why is there pulsation when I brake? I have replaced rotors and pads a couple of times in the last year.

Answer
Edward,
I have had problems if I used anything other that the original pads and rotors. Now I used Volvo pads and rotors not a problem. Now do you clean the surface where the rotor mounts? There might be a build up of "crud" that does not allow the rotor to set or sit flat against the hub