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 DiscCheck 2-2: Fuel Level Warning Inspection
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Connect the resistor(s) [A] (about 50 to 100 Ω) between
the fuel pump connector terminal [B] of the main harness
side and the battery negative (–) terminal [C] as shown.
Turn the ignition switch ...
Damping Force Adjustment (
ZX1000JC/KC)
To adjust the damping force, turn the damping adjuster
[A] until you feel a click.
The standard adjuster setting is the 18th click from the
1st of the fully clockwise position. If the damping feels too
soft or too stiff, adjust it in accordance with the following
table.
Damping Force Adj ...
KIBS Troubleshooting Outline
When an abnormality in the system occurs, the ABS indicator
light (LED) and KIBS indicator light (LED) light up and
the KIBS warning symbol are displayed on the LCD (Liquid
Crystal Display) to alert the rider. In addition, the nature of
the fault is stored in the memory of the KIBS hydraulic uni ...