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 DiscInquiries to Rider
DFI Diagnosis Flow Chart
Each rider reacts to problems in different ways, so it is important to
confirm what kind of symptoms
the rider has encountered.
Try to find out exactly what problem occurred under exactly what
conditions by asking the rider;
knowing this information may h ...
Outline
When a problem occurs with DFI system, the warning indicator
light (LED) [A] and FI warning symbol [B] goes on
to alert the rider. In addition, the condition of the problem is
stored in the memory of the ECU. For models equipped with
an immobilizer system, the warning indicator light (LED)
and ...
Drive Chain
The drive chain slack and lubrication
must be checked each day before riding
the motorcycle and must be maintained
in accordance with the Periodic
Maintenance Chart for safety and to
prevent excessive wear. If the chain
becomes badly worn or maladjusted -
either too loose or too tight - the c ...