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 DiscFront Fork Disassembly
Remove the front fork (see Front Fork Removal (Each
Fork Leg))
Drain the fork oil (see Front Fork Oil Change).
Take the dust seal [A] off the outer tube.
Remove the retaining ring [B].
Separate the outer tube from the inner tube.
Remove the following parts from the inner tube. ...
Lower Fairing Removal
Remove the quick rivets [A].
Remove:
Quick Rivets [A]
Bolts [B]
Pull up the core by the flat-head screwdriver (–), and then
remove the quick rivet.
Clear the hook portions on the upper edges [C] from the
slots, and remove the left lower fairing [D].
While pulling down ...
Daily Checks
Check the following items each day before you ride. The time required is
minimal,
and habitual performance of these checks will help ensure you a safe, reliable
ride.
If any irregularities are found during these checks, refer to the Maintenance
and
Adjustment chapter or see your dealer fo ...