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 DiscOil Pan Installation
If the oil filter holder bolt [A] was removed, tighten it.
Apply a non-permanent locking agent to the threads of
the oil filter holder bolt.
Torque - Oil Filter Holder Bolt: 35 N·m (3.6 kgf·m, 26 ft·lb)
Replace the O-rings [B] with new ones, and apply grease
to them.
Install the O-ri ...
ECU Removal
NOTICE
Never drop the ECU especially on a hard surface.
Such a shock to the ECU can damage it.
Remove the upper air cleaner housing (see Air Cleaner
Element Replacement in the Periodic Maintenance chapter).
Lift up the ECU [A] with rubber protector [B] to disconnect
the connectors [C]. ...
Chassis Parts Lubrication
Before lubricating each part, clean off any rusty spots with
rust remover and wipe off any grease, oil, dirt, or grime.
Lubricate the points listed below with indicated lubricant.
NOTE
Whenever the vehicle has been operated under
wet or rainy conditions, or especially after using a
high ...