hi . i have ad a annoying rattle on my 300 tdi . then sussed it was from front wheel . then sussed if u kept ya foot on brake pedal lightly it didnt rattle put new springs on pads other day still rattles only on bad roads which this island as loads of . while pads were out got me boy push on brake pedal n only one piston come out . so can anyone tell me is me caliper shot n if a caliper repair kit would sort it thanks steve