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 DiscBalancer Adjustment
Remove the left lower fairing (see Lower Fairing Removal
in the Frame chapter).
Start the engine and warm it up thoroughly.
Adjust the balancer gear backlash with the engine idling.
The amount of backlash can be changed by turning the
balancer shaft which has eccentric journals.
St ...
Compression Damping Force Adjuster and Rebound
Damping Force Adjuster Adjustment
The compression damping force adjuster
and the rebound damping force
adjuster are located on top of each front
fork leg.
Turn the adjuster clockwise with a
screwdriver to increase damping
force.
Turn the adjuster counterclockwise
to decrease damping force.
NOTICE
Do not force to t ...
Valve Clearance Inspection
NOTE
Valve clearance must be checked and adjusted when
the engine is cold (at room temperature).
Remove:
Crankshaft Sensor Cover (see Crankshaft Sensor Removal
in the Electrical System chapter)
Cylinder Head Cover (see Cylinder Head Cover Removal
in the Engine Top End chapter)
Turn t ...