6-33 Brake Wear
Your vehicle has four-wheel 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 won't 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.
Brake linings should always be replaced as complete
axle sets.
See ªBrake System Inspectionº in Section 7 of this manual
under Part C ªPeriodic Maintenance Inspections.º
6-50 Check Tire Pressure System (If Equipped)
The check tire pressure system can alert you to a
large change in the pressure of one tire. The system
won't alert you before you drive that a tire is low or
flat. You must begin driving before the system will
work properly.
The TIRE PRESSURE LOW message will appear on
the Driver Information Center (DIC) if pressure
difference (low pressure) is detected in one tire. The
check tire pressure system may not alert you if:
more than one tire is low,
the vehicle is moving faster than 65 mph (105 km/h),
the system is not yet calibrated,
the tire treadwear is uneven,
the compact spare tire is installed,
tire chains are being used, or
the vehicle is being driven on a rough or frozen road.
If the anti
-lock brake system warning light comes on,
the check tire pressure system may not be working
properly. See your dealer for service. Also, see
ªAnti
-Lock Brake System Warning Lightº in the Index.The check tire pressure system detects differences in
tire rotation speeds that are caused by changes in
tire pressure. The system can alert you about a low
tire
-- but it doesn't replace normal tire maintenance.
See ªTiresº in the Index.
When the TIRE PRESSURE LOW message appears on
the Driver Information Center, you should stop as soon
as you can and check all your tires for damage. If a tire
is flat, see ªIf a Tire Goes Flatº in the Index. Also check
the tire pressure in all four tires as soon as you can. See
ªInflation
-Tire Pressureº in the Index.
Any time you adjust a tire's pressure or have one or
more tires repaired or replaced, you'll need to reset
(calibrate) the check tire pressure system. You'll also
need to reset the system whenever you rotate the tires,
buy new tires and install or remove the compact spare.
Don't reset the check tire pressure system without first
correcting the cause of the problem and checking and
adjusting the pressure in all four tires. If you reset the
system when the tire pressures are incorrect, the check
tire pressure system will not work properly and may not
alert you when a tire is low or high.
6-54 Uniform Tire Quality Grading
Quality grades can be found where applicable on the tire
sidewall between tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, 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 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 and additional General Motors Tire
Performance Criteria (TPC) standards.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.
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.
