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 DiscEngine Removal
Support the rear part of the swingarm with a stand.
Squeeze the brake lever slowly and hold it with a band
[A].
WARNINGMotorcycle may fall over unexpectedly
resulting in
an accident or injury. Be sure to hold the front brake
when removing the engine.
NOTICE
Be sure ...
Dimmer Switch
High or low beam can be selected
with the dimmer switch. When the
headlight is on high beam ( ), the
high beam indicator light goes on.
High beam.......( )
Low beam.......( )
NOTE
When the headlight is on high beam,
both headlights go on. When the
headlight is on low beam, only one
headl ...
ESD (Electronic Steering Damper) ECU Removal (ZX1000JD/KD)
NOTICE
Never drop the ECU especially on a hard surface.
Such a shock to the ECU can damage it.
Lift up the front portion of the fuel tank, and hold it with a
suitable bar or block (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
NOTE
When removing the ESD ECU only, there ...