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 DiscFuel Pump Removal
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions, creating the
potential for serious burns. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light. Do not smoke. T ...
Starter Clutch Inspection
Remove:
Torque Limiter Cover (see Torque limiter Removal)
Turn the torque limiter [A] by hand. The torque limiter
should turn forward freely [B], but should not turn backward.
If the starter clutch does not operate as it should or if it
makes noise, go to the next step.
Disassem ...
Oil 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 ...