
Brake Wear
Your vehicle has front disc brakes and may have rear
drum brakes or rear disc brakes.
Disc brake pads have built-in wear indicators that make a
high-pitched warning sound when the brake pads are
worn and new pads are needed. The sound may come
and go or be heard all the time your vehicle is moving,
except when you are pushing on the brake pedal firmly.
{CAUTION:
The brake wear warning sound means that soon
your brakes will not work well. That could lead
to an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are first applied or lightly applied.
This does not mean something is wrong with your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque specifications.If you have rear drum brakes, they do not have wear
indicators, but if you ever hear a rear brake rubbing
noise, have the rear brake linings inspected immediately.
Also, the rear brake drums should be removed and
inspected each time the tires are removed for rotation or
changing. When you have the front brake pads
replaced, have the rear brakes inspected, too.
Brake linings should always be replaced as complete
axle sets.
SeeBrake System Inspection on page 6-24.
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a moderate brake stop, your disc
brakes adjust for wear. If you rarely make a moderate or
heavier stop, then your brakes might not adjust correctly.
If you drive in that way, then — very carefully — make a
few moderate brake stops about every 1,000 miles
(1 600 km), so your brakes will adjust properly.
If your brake pedal goes down farther than normal, your
rear drum brakes may need adjustment. Adjust them by
backing up and firmly applying the brakes a few times.
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Tire Size
The following illustration shows an example of a typical
passenger car tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter P as the
first character in the tire size means a passenger
vehicle tire engineered to standards set by the U. S.
Tire and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is 70, as shown in item C of the
illustration, it would mean that the tire’s sidewall is
70% 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 the speed rating of a tire. The
load range represents the load carry capacity a tire is
certified to carry. The speed rating is the maximum
speed a tire is certified 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, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to its
width.
5-48

Remove the valve cap from the tire valve stem. Press
the tire gage firmly onto the valve to get a pressure
measurement. If the cold tire inflation pressure matches
the recommended pressure on the Tire and Loading
Information label, no further adjustment is necessary. If
the inflation pressure is low, add air until you reach
the recommended amount.
If you overfill the tire, release air by pushing on the
metal stem in the center of the tire valve. Re-check the
tire pressure with the tire gage.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. SeeWhen It Is Time
for New Tires on page 5-53andWheel Replacement
on page 5-56for more information.The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first rotation
is the most important. SeePart A: Scheduled
Maintenance Services on page 6-4.
When rotating your tires, always use the correct rotation
pattern shown here.
Do not include the compact spare tire in the tire
rotation.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the tire and loading
information label. SeeLoading Your Vehicle on
page 4-27for an example of the tire and loading
information label and where it is located on your vehicle.
5-52

Make certain that all wheel nuts are properly tightened.
See “Wheel Nut Torque” underCapacities and
Specifications on page 5-80.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-58.
When It Is Time for New Tires
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.
You need a new tire if any of the following statements
are true:
•You can see the indicators at three or more places
around the tire.
•You can see cord or fabric showing through the
tire’s rubber.
•The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
•The tire has a bump, bulge, or split.
•The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
5-53

Buying New Tires
GM has developed and matched specific tires for your
vehicle. If you need replacement tires, GM strongly
recommends that you get tires that are the same size,
brand, load range, speed rating, and construction
type (radial and bias-belted tires) as your vehicle’s
original tires. This way, your vehicle will continue to have
tires that are designed to give the same performance
and vehicle safety, during normal use, as the original
tires. SeeTire Sidewall Labeling on page 5-46for
additional information.
{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes,
brands, or types (radial and bias-belted tires),
the vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes, brands, or types may also cause
damage to your vehicle. Be sure to use the
correct size, brand, and type of tires on all
wheels. It is all right to drive with your
compact spare temporarily, as it was
developed for use on your vehicle. See
Compact Spare Tire on page 5-66.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information Label. This label is
attached to the vehicle’s center pillar (B-pillar). See
Loading Your Vehicle on page 4-27, for more information
about the Tire and Loading Information Label.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability, and
resistance to rollover. Additionally, if your vehicle
has electronic systems such as, anti-lock brakes,
traction control, and electronic stability control, the
performance of these systems can be affected.
5-54

{CAUTION:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will
crash and suffer serious injury. Only use GM
speci c wheel and tire systems developed for
your vehicle, and have them properly installed
by a GM certi ed technician.
SeeBuying New Tires on page 5-54andAccessories
and Modifications on page 5-3for additional information.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
selection width.For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system developed
by the Unites States National Highway Traffic Safety
Administration (NHTSA), which grades tires by
treadwear, traction, and temperature performance. This
applies only to vehicles sold in the United States. The
grades are molded on the sidewalls of most passenger
car tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type snow
tires, space-saver, or temporary use spare tires, tires with
nominal rim diameters of 10 to 12 inches (25 to 30 cm),
or to some limited-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course.
For example, a tire graded 150 would wear one and
a half (1
1⁄2) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart significantly from the norm
due to variations in driving habits, service practices, and
differences in road characteristics and climate.
5-55

Traction — AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance.
Warning:The traction grade assigned to this tire is
based on straight-ahead braking traction tests, and does
not include acceleration, cornering, hydroplaning, or
peak traction characteristics.
Temperature — A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire’s resistance to the generation
of heat and its ability to dissipate heat when tested
under controlled conditions on a specified indoor
laboratory test wheel. Sustained high temperature can
cause the material of the tire to degenerate and
reduce tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to a
level of performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the
minimum required by law.Warning:The temperature grade for this tire is
established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you the
longest tire life and best overall performance.
Adjustments to wheel alignment and tire balancing will
not be necessary on a regular basis. However, if
you notice unusual tire wear or your vehicle pulling to
one side or the other, the alignment may need to
be checked. If you notice your vehicle vibrating when
driving on a smooth road, your tires and wheels
may need to be rebalanced. See your dealer for proper
diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts, and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
5-56

Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts, or
wheel nuts, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts, and wheel nuts for your vehicle.
{CAUTION:
Using the wrong replacement wheels, wheel
bolts, or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.
Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance, and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-58for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
Notice:Use tire chains only where legal and only
when you must. Use only SAE Class “S” type chains
that are the proper size for your tires. Install them
on the front tires and tighten them as tightly as
possible with the ends securely fastened. Drive
slowly and follow the chain manufacturer’s
instructions. If you can hear the chains contacting
your vehicle, stop and retighten them. If the contact
continues, slow down until it stops. Driving too
fast or spinning the wheels with chains on will
damage your vehicle.
5-57