If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterTire Tread Wear Inspection
As the tire tread wears down, the tire becomes more susceptible
to puncture and failure. An accepted estimate is
that 90% of all tire failures occur during the last 10% of tread
life (90% worn). So it is false economy and unsafe to use
the tires until they are bald.
Measure the tread depth a ...
Chassis Parts Lubrication
Before lubricating each part, clean off any rusty spots with
rust remover and wipe off any grease, oil, dirt, or grime.
Lubricate the points listed below with indicated lubricant.
NOTE
Whenever the vehicle has been operated under
wet or rainy conditions, or especially after using a
high ...
Fuel Tank and Cap Inspection
Visually inspect the gasket [A] on the tank cap for any
damage.
Replace the gasket if it is damaged.
Check to see if the water drain pipe [B] and fuel breather
pipe [C] in the tank are not clogged. Check the tank cap
breather also.
If they are clogged, remove the tank and drain it ...