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 DiscRelay Box Removal
Remove the left fuel tank cover (see Fuel Tank Removal
in the Fuel System (DFI) chapter).
Disconnect the connectors [A].
Pull out the relay box [B] from the rubber protector [C].
NOTE
The relay box has relays and diodes. The relays and
diodes can not be removed.
Relay Box Installa ...
Oxygen Sensor Removal (Equipped Models)
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Right Lower Fairing (see Lower Fairing Removal in the
Frame chapter)
Disconnect the oxygen sensor lead connector [A].
NOTICE
Do not pull strongly, twist, or bend the oxygen sensor
lead. This may cause the wi ...
Catalytic Converter
This motorcycle is equipped with a
catalytic converter in the exhaust system.
The converter reacts with carbonmonoxide,
hydrocarbons and nitrogen
oxides to convert them into carbon
dioxide, water, nitrogen and oxygen resulting
in much cleaner exhaust gases
to be discharged into the atmosphe ...