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 DiscBrake Hose and Pipe Damage and Installation Condition Inspection
Inspect the brake hoses, pipes and fittings for deterioration,
cracks and signs of leakage.
The high pressure inside the brake line can cause fluid to
leak [A] or the hose to burst if the line is not properly maintained.
Bend and twist the rubber hose while examining
it.
Replace the ...
Tire 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 ...
Washing Your Motorcycle
Rinse your bike with cold water from
a garden hose to remove any loose
dirt.
Mix a mild neutral detergent (designed
for motorcycles or automobiles)
and water in a bucket. Use
a soft cloth or sponge to wash your
motorcycle. If needed, use a mild degreaser
to remove any oil or greas ...