Doing simple rear pad/rotor change on my 2012 C30, only 90,000 miles.
Turn right side piston back in, no issue. Turn left side piston back in, brake fluid comes out of boot. Its definitely leaking now, so seal is bad. Wasn't leaking before brake job.
My 1997 850 with 205,000 miles still has original calipers!!
Does this different design, instead of just pushing back pistons, cause failure more often? I wonder if turning the piston can tear old seals.