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 DiscSpecial Tools
Bearing Driver Set:
57001-1129
Jack:
57001-1238
Bearing Remover Head, 25 × 28:
57001-1346
Bearing Remover Shaft, 13:
57001-1377
Jack Attachment:
57001-1608 ...
Caliper Installation
Install the caliper and brake hose lower end.
For the front caliper, be sure to install the collars [A].
Replace the washers on each side of hose fitting with new
ones.
Touch the brake hoses [A] to the stopper [B] of the caliper.
Front Calipers [C]
Rear Caliper [D]
Tighten:
To ...
Check 2-3: Intake Air Temperature Inspection
Disconnect the intake air temperature sensor connector
[A] (see Intake Air Temperature Sensor Removal in the
Self-Diagnosis System chapter).
Connect the variable rheostat [B] to the R/BK lead [C] and
BR/BK lead [D] terminals.
Turn the ignition switch to ON.
Read the temperatur ...