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 DiscRear Shock Absorber Scrapping
WARNINGPressurized nitrogen may explode when
heated.
The rear shock contains nitrogen gas. To avoid
an explosion, do not incinerate the shock body
without first releasing the nitrogen and removing
the shraeder valve.
Remove the rear shock absorber (see Rear Shock Ab ...
Front Wheel Removal
Remove:
Front Caliper Mounting Bolts [A] (Both Sides)
Front Caliper [B] (Both Sides)
Loosen:
Front Axle Clamp Bolts [A] (Right Side)
Front Axle [B]
Remove the lower fairings (see Lower Fairing Removal in
the Frame chapter).
Raise the front wheel off the ground.
...
KIBS Hydraulic Unit Terminal Names
1. Ground: BK
2. CAN Communication Line (High): GY/BL
3. Front Wheel Rotation Sensor Signal Input: Y
4. Power Supply: BR/W
5. KIBS Kawasaki Self-Daignosis System Terminal: P
6. Front and Rear Brake Light Switch Signal: BL/R
7. Unused
8. Front Wheel Rotation Sensor Signal Output: G/Y
9. P ...