If they show any damage, replace it.

Caliper Fluid Seal Damage
Caliper Piston and Cylinder DamageValve Clearance
Valve and valve seat wear decreases
valve clearance, upsetting valve timing.
NOTICE
If valve clearance is left unadjusted,
wear will eventually
cause the valves to remain
partly open; which lowers performance,
burns the valves and
valve seats, and may cause serious
engine damage.
Valve cle ...
Cylinder (Upper Crankcase) Wear Inspection
Split the crankcase (see Crankcase Splitting).
Remove the pistons (see Piston Removal).
Assemble the cylinder (upper crankcase) [A], the cylinder
head [B] and the cylinder head gasket [C].
Tighten the cylinder head bolts (see Cylinder Head Installation
in the Engine Top End chapter).
...
Alternator Cover Installation
Using a high flash-point solvent, clean off any oil or dirt
that may be on the silicone sealant coating area. Dry
them with a clean cloth.
Apply silicone sealant to the alternator lead grommet and
crankcase halves mating surface [A] on the front and rear
sides of the cover mount.
Sea ...