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 DiscSubthrottle Sensor Output Voltage Inspection
Measure the output voltage at the subthrottle sensor in
the same way as input voltage inspection, note the following.
Disconnect the subthrottle sensor connector and connect
the setting adapter [A] between these connectors.
Special Tool - Throttle Sensor Setting Adapter: 57001
-1538
...
Wheel Inspection
Raise the front/rear wheel off the ground.
Special Tools - Jack: 57001-1238
Jack Attachment: 57001-1608
Spin the wheel lightly, and check for roughness or binding.
If roughness or binding is found, replace the hub bearings
(see Hub Bearing Removal/Installation).
Inspect the wh ...
Loading and accessories information
WARNINGIncorrect loading, improper installation
or use of accessories,
or modification of your motorcyclemay
result in an unsafe riding
condition. Before you ride the
motorcycle, make sure it is not
overloaded and that you have
followed these instructions.
With the ...