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 Pedal Position Adjustment
NOTE
Usually it is not necessary to adjust the pedal position,
but always adjust it when push rod locknut has been
loosened.
Loosen the locknut [A] and turn the push rod with the hex
head [B] to achieve the correct pedal position.
If the length [C] shown is 69 ±1 mm (2.7 ±0.04 in.), th ...
Thermostat Removal
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Air Cleaner Housing (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter)
Throttle Body Assy (see Throttle Body Assy Removal in
the Fuel System (DFI) chapter)
Throttle Body Assy Holder Clamp [A]
...
Steering Play Adjustment
Remove:
Steering Stem Head with Handlebars (see Handlebar
Removal in the Steering chapter).
Bend the claws [A] of the claw washer [B] straighten.
Remove:
Steering Stem Locknut [C]
Claw Washer
Adjust the steering using the steering stem nut wrench
[A].
Special Tool - Ste ...