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 DiscIntake Air Pressure Sensor #1 Output Voltage Inspection
Measure the output voltage at the intake air pressure sensor
#1 in the same way as input voltage inspection, note
the following.
Disconnect the intake air pressure sensor #1 connector
and connect the measuring adapter [A] between these
connectors.
[B] Main Harness
[C] Intake Air Pressu ...
Warning Indicator Light (LED)
Light (LED) Inspection
The warning indicator light (LED) [A] is used for the FI indicator,
immobilizer indicator (immobilizer equipped models),
water temperature warning indicator and oil pressure
warning indicator.
In this model, the warning indicator light (LED) (FI/immobilizer)
goes ...
Braking
Close the throttle completely, leaving
the clutch engaged (except when
shifting gears) so that the engine will
help slow down the motorcycle.
Shift down one gear at a time so that
you are in 1st gear when you come
to a complete stop.
When stopping, always apply both
brakes at the ...