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 DiscBreak-in
The first 1 600 km (1 000 mi) that the motorcycle is ridden is designated
as the
break-in period. If the motorcycle is not used carefully during this period, you
may
very well end up with a “broken down” instead of a “broken in” motorcycle after
a
few thousand kilometers.
The fol ...
Rear Shock Absorber Inspection
Remove the rear shock absorber (see Rear Shock Absorber
Removal).
Visually inspect the following items.
Smooth Stroke
Oil Leakage
Crack or Dent
If there is any damage to the rear shock absorber, replace
it.
Visually inspect the rubber bushing [A].
If it show any signs o ...
Radiator Cap Inspection
Remove:
Radiator Cap (see Coolant Change in the Periodic Maintenance
chapter)
Check the condition of the bottom [A] and top [B] valve
seals and valve spring [C].
If any one of them shows visible damage, replace the cap
with a new one.
Install the cap [A] on a cooling system pr ...