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 DiscPower Mode Indicator
This indicator shows the selected
Power Mode. For more detailed information
about the power mode, see
power mode section in the How to Ride
the Motorcycle chapter.
A. Power Mode Indicator
NOTE
When all power mode indicators go
off, the battery voltage is insufficient.
Have the machine ...
Rear Caliper Removal
Remove:
Bolt [A]
Rear Wheel Rotation Sensor [B]
Loosen the banjo bolt [C] at the brake hose lower end,
and tighten it loosely.
Loosen the caliper holder pin [D].
Remove the rear wheel (see Rear Wheel Removal in the
Wheels/Tires chapter).
Unscrew the banjo bolt and remove t ...
DFI Power Source
ECU Fuse Removal
Refer to the 30 A Main/15 A ECU Fuse Removal in the
Electrical System chapter.
ECU Fuse Installation
If a fuse fails during operation, inspect the DFI system to
determine the cause, and then replace it with a new fuse
of proper amperage.
Refer to the Fuse Installation in ...