Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionBrake 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 ...
Battery Installation
Visually inspect the surface of the battery container.
If any signs of cracking or electrolyte leakage from the
sides of the battery.
Put the battery into the rear fender
Install the band [A].
Connect the positive (+) cable [B] (red cap) to the positive
(+) terminal first, and then ...
Hub Bearing Installation
Before installing the hub bearings, blow any dirt or foreign
particles out of the hub with compressed air to prevent
contamination of the bearings.
Replace the bearings with new ones.
Install the bearings by using the bearing driver set which
does not contact the bearing inner race.
...