As far as I can see the amount of movement of the piston /caliper when handbrake is pulled on is 'low' ie less than a mm !!
it is the same on BOTH sides. this is when I have caliper off and have wound the piston back against the 'stop' has any-body actually measured how much it moves? I guess it does not need to go far as the pads are 'touching' most of the time.
I have adjusted both wee adjusters in back of caliper and taken ALL slack out of cable, AND it sits against the stops when OFF
I found that the bonding on one of the pads had failed letting it 'drop' a touch so losing ALL surface area, this would explain why I had a stack of slack to take up last week as I did my 'rounds' not very carefully obviously!! (I fitted new cables the month earlier and assumed it was just cable bedding in)
![Sad :(](./images/smilies/icon_sad.gif)
I did see thsi once before about 20 years ago on a FIAT 128 and they dropped into the gap tween disc and caliper and so stopped the car from reversing!!