9-24 Vehicle Care
Brakes
This vehicle has 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 can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
an accident. When the brake
wear warning sound is heard,
have the vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair. Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the 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 torque
specifications in
Capacities and
Specifications on page 11‑2.
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer/retailer 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
that brake service might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes —for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.
Vehicle Care 9-31
2. Locate the aim dot on the lens ofthe low-beam headlamp.
3. Measure the distance from the ground to the aim dot on the
low-beam headlamp. Record the
distance.
4. At the wall measure from theground upward (A) to the
recorded distance from
Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall the width of the
vehicle at the height of the mark
in Step 4.
Notice: Do not cover a headlamp
to improve beam cut-off when
aiming. Covering a headlamp may
cause excessive heat build-up
which may cause damage to the
headlamp. 6. Turn on the low-beam
headlamps and place a piece of
cardboard or equivalent in front
of the headlamp not being
adjusted. This allows only the
beam of light from the headlamp
being adjusted to be seen on the
flat surface.
Vehicle Care 9-47
If you choose to use winter tires:
.Use tires of the same brand and
tread type on all four wheel
positions.
.Use only radial ply tires of the
same size, load range, and
speed rating as the original
equipment tires.
Winter tires with the same speed
rating as your original equipment
tires may not be available for H, V,
W, Y, and ZR speed rated tires.
If you choose winter tires with a
lower speed rating, never exceed
the tire's maximum speed capability.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
examples below show a typical
passenger vehicle tire and a
compact spare tire sidewall.
Passenger (P-Metric) Tire Example
(A) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size” illustration later in this
section for more detail.
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
(C) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with the
U.S. Department of
Transportation Motor Vehicle
Safety Standards.
(D) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT (Department
of Transportation) code is the
Tire Identification Number (TIN).
The TIN shows the
manufacturer and plant code,
tire size, and date the tire was
manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.
Vehicle Care 9-49
(E) Tire Inflation:The
temporary use tire or compact
spare tire should be inflated to
420 kPa (60 psi). For more
information on tire pressure and
inflation see Tire Pressure
on
page 9‑53
.
(F) Tire Size
:A combination of
letters and numbers define a
tire's width, height, aspect ratio,
construction type, and service
description. The letter T as the
first character in the tire size
means the tire is for temporary
use only.
(G) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
Tire Designations
Tire Size
The following illustration shows
an example of a typical
passenger vehicle 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 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.
9-50 Vehicle Care
(F) Service Description:These
characters represent the load
index and speed rating of the
tire. The load index 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.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in psi (pounds per
square inch) or kPa (kilopascal).
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.
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.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in psi (pounds per
square inch) or kPa (kilopascal) before a tire has built up heat
from driving. See
Tire Pressure
on page 9‑53.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) motor vehicle safety
standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
on page 8‑12.
9-66 Vehicle Care
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/retailer if any of
these conditions exist.
Your dealer/retailer will know the
kind of wheel you need.
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 the
wheels, wheel bolts, wheel nuts,
or Tire Pressure Monitor System
(TPMS) sensors, replace them only
with new GM original equipment
parts. This way, you will be sure to
have the right wheel, wheel bolts,
wheel nuts, and TPMS sensors for
the vehicle.
{WARNING
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.
See If a Tire Goes Flat
on
page 9‑67for more information.
9-70 Vehicle Care
3. Turn the wheel wrenchcounterclockwise to loosen all
the wheel nuts, but do not
remove them yet.
Notice: Make sure that the jack
lift head is in the correct position
or you may damage your vehicle.
The repairs would not be covered
by your warranty.4. Position the jack head, as shown
Set the jack to the necessary
height before positioning it below
the jacking point.5. Attach the jack handle.
{WARNING
Getting under a vehicle when it is
jacked up is dangerous. If the
vehicle slips off the jack, you
could be badly injured or killed.
Never get under a vehicle when it
is supported only by a jack.