Disc brake caliper lever bumps into caliper body

Not sure if it is still actual but making lever go further than it suppoed to WILL result in brake caliper failure. Inside a caliper there is a piston. Piston is made out of two cylinders, one is has a notch preventing it prom turning, other turns freely. Between cylinders there are 3 metal balls that gave grooves that they sit in.Grooves have dynamic depth. When lever is pulled the turning cylinder spins and balls are pushed out of deeper grooves and made to go up to less deeper part of a groove. That pushes the piston that pushes the prake pad. If cylinder is turned too much balls fall out of their groves and braking mechanism fails. To repair it you have to take caliper apart and lace balls back to their grooves.