can worn break pads cause vibration when braking? i believe rotors can cause this but what if the rotors are good.. then can the brakes?

 

The most likely cause is a buildup of an uneven coating of brake pad deposits on the surface of the rotors. You can avoid it by properly bedding your brake pads; once it happens, you can try fixing it by re-bedding, by sanding the surface of the rotors, by turning the rotors, or by replacing the rotors.

You may want to read the Stoptech White Papers, including:
The "Warped" Brake Disc and Other Myths of the Braking System
Pad and Rotor Bed-In Theory, Definitions and Procedures

 

Vibration from an out of round rotor, come from bad wheel bearings or control arm bushings...Get your tech to check your wheel bearings, and bushings out...Then see if your rotors can be saved, by turning them....Also a bent wheel hub can have the same effect...Take it to your tech.