Caliper Inspection: Piston
WARNING: This page is about a different car, the 2008 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Since the piston surface is plated, do not repair using sandpaper.
Check piston surface for corrosion, wear, and damage. If any non-standard condition is detected, replace applicable part.