i had a funny prob.

i bought my second hand car almost 1 year ago. and recently changed the brake pads. And i find that the pad does not in contact fully with the disc.

now only i realise that the previous pads leave a thin protuding line at the outer most perimeter of the disc, while the new pads sit on top of the protuding line. This cause a untouched area of around 1 inch thick.

how is this possible? why my prevoius pad and current pad are not the same size? old one is smaller and new one is bigger.. or else it won leave a thin line at the disc as the position of the pads is not adjustable.