(C) Aspect Ratio:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is
60, as shown in item C of the illustration, it would
mean that the tire’s sidewall is 60 percent as
high as it is wide.
(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction;
the letter D means diagonal or bias ply
construction; and the letter B means belted-bias
ply construction.
(E) Rim Diameter:Diameter of the wheel
in inches.
(F) Service Description:These characters
represent the load range and speed rating of the
tire. The load index represents the load carry
capacity a tire is certi ed to carry. The load index
can range from 1 to 279. The speed rating is
the maximum speed a tire is certi ed to carry a
load. Speed ratings range from A to Z.Tire Terminology and De nitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the
tire. Air pressure is expressed in pounds
per square inch (psi) or kilopascal (kPa).
Accessory Weight:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic
transmission/transaxle, power steering, power
brakes, power windows, power seats, and
air conditioning.
Aspect Ratio:The relationship of a tire’s height
to its width.
Belt:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
426
Maintenance Footnotes
†The U.S. Environmental Protection Agency or
the California Air Resources Board has determined
that the failure to perform this maintenance item
will not nullify the emission warranty or limit
recall liability prior to the completion of the
vehicle’s useful life. We, however, urge that all
recommended maintenance services be performed
at the indicated intervals and the maintenance
be recorded.
(a)Visually inspect brake lines and hoses for
proper hook-up, binding, leaks, cracks, cha ng,
etc. Inspect disc brake pads for wear and rotors for
surface condition. Inspect other brake parts,
including calipers, parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing
parts or signs of wear. Inspect power steering lines
and hoses for proper hook-up, binding, leaks,
cracks, cha ng, etc.(c)Visually inspect hoses and have them replaced
if they are cracked, swollen, or deteriorated.
Inspect all pipes, ttings, and clamps; replace with
genuine GM parts as needed. To help ensure
proper operation, a pressure test of the cooling
system and pressure cap and cleaning the outside
of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or
cracking. Replace wiper blades that appear worn
or damaged or that streak or miss areas of
the windshield.
(e)Make sure the safety belt reminder light and all
your belts, buckles, latch plates, retractors, and
anchorages are working properly. Look for any
other loose or damaged safety belt system parts. If
you see anything that might keep a safety belt
system from doing its job, have it repaired. Have
any torn or frayed safety belts replaced. Also look
for any opened or broken airbag coverings, and
have them repaired or replaced. The airbag system
does not need regular maintenance.
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