If the disc has worn past the service limit, replace it.
Measuring Area [B]

Brake Disc Thickness Standard:
Front 5.3
5.7 mm (0.21
0.22 in.)
Rear 4.8
5.2 mm (0.19
0.20 in.)
Service Limit:
Front 5.0 mm (0.20 in.)
Rear 4.5 mm (0.18 in.)
Brake Disc Installation
Brake Disc Warp InspectionESD (Electronic Steering Damper) ECU Error (Service Code E3b, ZX1000JD/KD)
If this service code appears, check that the following parts
are correctly.
Crankshaft Sensor
Gear Position Switch
Starter Lockout Switch
Main Throttle Sensor
Rear Wheel Rotation Sensor
If these parts are normal, check the ESD ECU for its
ground and power supply (see ESD ECU Power Supply
...
Tie-Rod Removal
Squeeze the brake lever slowly and hold it with a band
[A].
Remove the front footpeg bracket bolts [A].
Raise the rear wheel off the ground with the jack (see
Rear Shock Absorber Removal).
Special Tools - Jack: 57001-1238
Jack Attachment: 57001-1608
Remove:
Upper ...
Stick Coil Input Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the ECU (see ECU Removal in the Fuel System
(DFI) chapter).
Do not disconnect the ECU connectors.
Connect a digital meter [A] to the connector [B] with the
needle adapter set.
Special Tool - N ...