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 DiscIntake Air Temperature Sensor Resistance Inspection
Remove the intake air temperature sensor (see Intake Air
Temperature Sensor Removal).
Suspend the sensor [A] in a container of machine oil so
that the heat-sensitive portion is submerged.
Suspend a thermometer [B] with the heat-sensitive portion
[C] located in almost the same depth with ...
Intake Air Pressure Sensor #2 Output Voltage Inspection
Measure the output voltage at the intake air pressure sensor
#2 in the same way as input voltage inspection, note
the following.
Disconnect the intake air pressure sensor #2 connector
and connect the measuring adapter [A] between these
connectors.
[B] Main Harness
[C] Intake Air Pressu ...
Precautions
There are a number of important precautions that are
musts when servicing electrical systems. Learn and observe
all the rules below.
Do not reverse the battery cable connections. This will
burn out the diodes on the electrical parts.
Always check battery condition before condemning other
...