right, after wearinf my vaux OE pads to about 14k miles i decided to change to ebc pad, after that i now find tat when im braking heavily the pedal vibrates up and down, but it doesnt happen when breaking gently what is it? discs bent? would it be due to wearing the old pads down too much, or would it be the new discs? how much would a set of dics cost? ive been told they are about £40 a set from, halfords