[TR] caliper piston pop-out?

[Nolan]

>I wonder if something like the o-ring-like piston rubber would ever
> get twisted, come out-of-grove or not 'correctly center' itself on the
> traveling piston if ever this ever reoccurs?  Would the piston 'push-out' 
> so
> far as to establish a leak or take in air?

The answer partially depends on the vehicle.  If the piston is popped all 
the way out, air will certainly be introduced.  The re-installation of the 
piston can twist the seal.  Otherwise, as long as the piston stays in the 
bore, the seal will not be twisted.