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 DiscStick Coil Inspection
Remove the stick coils (see Stick Coil Removal).
Measure the primary winding resistance [A] as follows.
Connect the hand tester between the coil terminals.
Set the tester to the × 1 Ω range, and read the tester.
Measure the secondary winding resistance [B] as follows.
Conn ...
Charging Condition Inspection
Battery charging condition can be checked by measuring
battery terminal voltage with a digital voltmeter [A].
Remove the seat (see Seat Removal in the Frame chapter).
Disconnect the battery terminals.
NOTICE
Be sure to disconnect the negative (–) cable first.
Measure the battery ...
Coupling Bearing Installation
Replace the bearing with a new one.
Press in the bearing [A] until it is bottomed.
Special Tool - Bearing Driver Set [B]: 57001-1129
Pack the bearing with high-temperature grease.
Replace the circlip with a new one.
Special Tool - Inside Circlip Pliers: 57001-143
Replace the grease se ...