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 DiscTire Repair
Currently two types of repair for tubeless tires have come
into wide use. One type is called a temporary (external) repair
which can be carried out without removing the tire from
the rim, and the other type is called permanent (internal)
repair which requires tire removal. It is generally unders ...
Radiator Fan System
Fan Motor Inspection
Remove the air cleaner housing (see Air Cleaner Housing
Removal in the Fuel System (DFI) chapter).
Disconnect the connector [A].
Using an auxiliary leads, supply battery power to the fan
motor.
If the fan does not rotate, the fan motor is defective and
must be re ...
Check 3-1: CAN Communication Line Resistance Inspection
Set the hand tester [A] to the ×1 Ω range and connect it
to the terminal [11] and [12] in the meter unit.
Special Tool - Hand Tester: 57001-1394
CAN Communication Line Resistance (at Meter Unit)
Standard: 122 126 Ω
If the tester reading is not specified, replace the meter ...