If they show any damage, replace it.

Caliper Fluid Seal Damage
Caliper Piston and Cylinder DamageWiring Diagram (Other than US, CA and CAL without KIBS Models)
ZX1000JC
ZX1000JD
...
General Lubrication
Lubricate the points shown below,
with either motor oil or regular grease,
in accordance with the Periodic Maintenance
Chart or whenever the vehicle
has been operated under wet or rainy
conditions.
Before lubricating each part, clean off
any rusty spots with rust remover and
wipe off any g ...
Piston Ring, Piston Ring Groove Wear Inspection
Check for uneven groove wear by inspecting the ring seating.
The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.
With the piston rings in their grooves, make several measurements
with a thickness gauge [A] to determine pisto ...