Page 72 - Driving Commercial Vehicles Manual

driving commercial vehicles

Tire condition

Never operate a
vehicle that has bald or
damaged tires. Tires are
defective if they:
• have any tread
damage, including
cuts, cracks or snags,
that are longer that
Various types of tire wear 2.5 cm (1 in) and deep
patterns. enough to expose the
ply cords
• have less than 3 mm (1/8 in) of tread on a front tire or 1.6 mm (1/16 in) of
tread on a rear tire and are being used on a vehicle with a GVW of 5,500 kg
or more
• have less than 1.6 mm
(1/16 in) of tread and
31
32 are being used on a
33
trailer
• have less than 3.5 mm
(3/16 in) of tread in the
Ensure the tread depth case of a winter tire.
on your tires conforms
to the standards set out For more details on tire
in the Motor Vehicle Act requirements, consult
Regulations. the Motor Vehicle Act
Regulations.

Tire problems

Here are some common tire problems:
• too much or too little air pressure — use a gauge to ensure correct pressure
• tire wear — check for tread depth and tread recap separation

• cuts, abrasions, exploding cord, sidewall separation or bulges
• tires in contact with each other or tires in contact with any part of the vehicle
• cracked or leaking valve stems
• a mixture of different sizes or radial and bias-ply tires being used on the
same axle — these can be mixed on the same vehicle but not on the same
axle (not a recommended practice).
Note: If you change a tire, stop after a short while and check that the wheel
nuts are tight. Always use a torque wrench to tighten and check wheel nuts.

56