If a master cylinder or piston shows any damage, replace them.

If a cup is worn, damaged softened (rotted), or swollen, the piston assembly should be replaced to renew the cups.
If fluid leakage is noted at the brake lever, the piston assembly should be replaced to renew the cups.
If they are damaged, replace them.
If the springs are damaged, replace them.
If the relief port becomes plugged, the brake pads will drag on the disc. Blow the ports clean with compressed air.
Front Master Cylinder [I] Rear Master Cylinder [J]

Rear Master Cylinder Installation
Brake DiscBreak-in
The first 1 600 km (1 000 mi) that the motorcycle is ridden is designated
as the
break-in period. If the motorcycle is not used carefully during this period, you
may
very well end up with a “broken down� instead of a “broken in� motorcycle after
a
few thousand kilometers.
The fol ...
Meter Unit Removal/Installation
Remove the upper fairing assembly (see Upper Fairing
Assembly Removal in the Frame chapter)
Remove the bolt [A] (other than US, CA and CALmodels).
Slide back the dust cover and disconnect the meter unit
connector [B].
Remove:
Bolts [A]
Nut [B] (other than US, CA and CAL mode ...
Lights and Switches Operation Inspection
First Step
Set the gear position in the neutral position.
Turn the ignition switch to ON.
The following lights should go on according to below table.
If the following light does not go on, inspect the meter
unit (see Meter Unit Inspection in the Electrical System
chapter).
...