If they show any damage, replace it.

Caliper Fluid Seal Damage
Caliper Piston and Cylinder DamageSteering Stem Bearing Lubrication
Remove the steering stem (see Stem, Stem Bearing Removal
in the Steering chapter).
Using a high flash-point solvent, wash the upper and
lower ball bearings [A] in the cages.
Wipe the upper and lower outer races which are press
-fitted into the head pipe to clean off grease and dirt.
V ...
Cylinder Head Cover Installation
Replace the cylinder head cover gasket [A] with a new
one
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 [B] to the cylinder head as shown
in the figure.
Sealant - Li ...
Rear Master Cylinder Installation
Replace the washers that are on each side of hose fitting
with new ones.
Install the brake hose [A].
Touch the brake hose to the stopper [B] of the rear master
cylinder.
Tighten:
Torque - Brake Hose Banjo Bolt: 25 N·m (2.5 kgf·m, 18 ft·lb)
Install the master cylinder, the brack ...