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 DiscLubrication
It is important to lubricate rotating or sliding parts during
assembly to minimize wear during initial operation. Lubrication
points are called out throughout this manual, apply
the specific oil or grease as specified.
Direction of Engine Rotation
When rotating the crankshaft by hand, the fre ...
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 ...
Hoses and Pipes
Hose Installation
Install the hoses and pipes, being careful to follow bending
direction. Avoid sharp bending, kinking, flattening or
twisting.
Run the hoses (see Cable, Wire, and Hose Routing section
in the Appendix chapter).
Install the clamp [A] as near as possible to the hose end
...