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 DiscKey Registration
Case 1: When the ignition key has been lost or additional
spare ignition key is required.
Prepare a new spare ignition key.
Cut the key in accordance with the shape of the current
ignition key.
Remove the rear seat (see Rear Seat Removal in the
Frame chapter).
Remove the immobilizer/K ...
Connecting Rod Big End Side Clearance Inspection
Measure connecting rod big end side clearance.
Insert a thickness gauge [A] between the big end and either
crank web to determine clearance.
Connecting Rod Big End Side Clearance
Standard: 0.13 0.38 mm
(0.0051 0.0150 in.)
Service Limit: 0.58 mm (0.023 in.)
If the clearance exceeds ...
Spring Plate Free Play Adjustment
NOTE
The free play adjustment is performed by replacing the
steel plate(s).
Measure the clutch spring plate free play (see Clutch
Spring Plate Free Play Measurement), and then replace
the steel plate(s) which brings the free play within the
usable range.
Spring Plate Free Play
Usable ...