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 DiscBrake Hose and Pipe Damage and Installation Condition Inspection
Inspect the brake hoses, pipes and fittings for deterioration,
cracks and signs of leakage.
The high pressure inside the brake line can cause fluid to
leak [A] or the hose to burst if the line is not properly maintained.
Bend and twist the rubber hose while examining
it.
Replace the ...
Idle Speed Control Valve Actuator Resistance Inspection
Turn the ignition switch to OFF.
Remove the air cleaner housing (see Air Cleaner Housing
Removal in the Fuel System (DFI) chapter).
Disconnect the idle speed control valve actuator connector
[A].
Connect a digital meter to the idle speed control valve
actuator connector [A]
...
Rider’s Seat Removal
Remove the bolts and seat cover.
A. Bolts
B. Seat Cover
Remove the mounting bolts and pull
off the seat upward.
A. Mounting Bolts
B. Rider’s Seat ...