hi every one,,bit of a quary realy..few weeks back i changed my rear pads,came to check them and the one brake pad was almost gone,,and relised only the one piston was working hence the bad ware on the one pad,,i there for stripped the caliper down and sorted the problem and once again put new pads on,,how ever now im getting a grinding noise,,thats on and off wen im driveing,,could the disc be warped of sumat due to the previuose problem,,hope iv described it good enuff,,cheers