tires GMC SIERRA CLASSIC 2007 Owner's Guide

Washing Your Vehicle............................... 592
Cleaning Exterior Lamps/Lenses................ 593
Finish Care............................................... 593
Windshield and Wiper Blades.................... 594
Aluminum or Chrome-Plated Wheels......... 594
Tires......................................................... 595
Sheet Metal Damage................................. 595
Finish Damage.......................................... 596
Underbody Maintenance............................ 596
Chemical Paint Spotting............................ 596
Vehicle Care/Appearance Materials............ 597
Vehicle Identication.................................. 598
Vehicle Identication Number (VIN)........... 598
Service Parts Identication Label............... 598Electrical System........................................ 599
Add-On Electrical Equipment..................... 599
Windshield Wiper Fuses............................ 599
Power Windows and Other Power
Options.................................................. 599
Fuses and Circuit Breakers....................... 600
Instrument Panel Fuse Block..................... 600
Center Instrument Panel Fuse Block......... 602
Underhood Fuse Block.............................. 603
Capacities and Specications.................... 609
Section 5 Service and Appearance Care
467

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 rmly.
{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 rst 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
specications.
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. Rear brake drums should
be removed and inspected each time the tires
are removed for rotation or changing. Drum brakes
have an inspection hole to inspect lining wear
during scheduled maintenance. When you have
the front brake pads replaced, have the rear
brakes inspected, too.
Brake linings should always be replaced as
complete axle sets.
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 brake stop, your brakes
adjust for wear.
519

Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your GM Warranty booklet
for details. For additional information refer to
the tire manufacturer’s booklet included with your
vehicle.
{CAUTION:
Poorly maintained and improperly used
tires are dangerous.
Overloading your vehicle’s tires can
cause overheating as a result of too
much friction. You could have an
air-out and a serious accident. See
Loading Your Vehicle on page 409.
CAUTION: (Continued)
CAUTION: (Continued)

Underinated tires pose the
samedanger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your vehicle’s tires are cold. See
Inflation - Tire Pressure on page 551.
Overinated tires are more likely
to be cut, punctured, or broken by a
sudden impact — such as when
you hit a pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents.
If the tire’s tread is badly worn, or
if your vehicle’s tires have been
damaged, replace them.
543

20-Inch Tires
If your vehicle has the optional 20-inch
P275/55R20 size tires, they are classied as
touring tires and are designed for on road use. The
low-prole, wide tread design is not recommended
for “off-road” driving or commercial uses such
as snow plowing. SeeOff-Road Driving on
page 372andAdding a Snow Plow or Similar
Equipment on page 416for additional information.
Tire Sidewall Labeling
Useful information about a tire is molded into the
sidewall. The following illustrations are examples
of a typical P-Metric and a LT-Metric tire sidewall.
(A) Tire Size:The tire size code is a combination
of letters and numbers used to dene 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.
Passenger (P-Metric) Tire
544

(B) TPC Spec (Tire Performance Criteria
Specication):Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications 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 Identication Number (TIN):The letters
and numbers following DOT code are the Tire
Identication 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.(E) Tire Ply Material:The type of cord and
number of plies in the sidewall and under
the tread.
(F) Uniform Tire Quality Grading (UTQG):Tire
manufacturers are required to grade tires
based on three performance factors: treadwear,
traction, and temperature resistance. For more
information, seeUniform Tire Quality Grading on
page 559.
(G) Maximum Cold Ination Load
Limit:Maximum load that can be carried and the
maximum pressure needed to support that load.
For information on recommended tire pressure see
Ination - Tire Pressure on page 551andLoading
Your Vehicle on page 409.
545

(A) Tire Size:The tire size code is a combination
of letters and numbers used to dene 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
Specication):Original equipment tires designed
to GM’s specic tire performance criteria have
a TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all
federal safety guidelines.
(C) Dual Tire Maximum Load:Maximum load
that can be carried and the maximum pressure
needed to support that load when used in a dual
conguration. For information on recommended
tire pressure seeInation - Tire Pressure on
page 551andLoading Your Vehicle on page 409.
(D) 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.
(E) Tire Identication Number (TIN):The letters
and numbers following DOT code are the Tire
Identication 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.
Light Truck (LT-Metric) Tire
546

Occupant Distribution:Designated seating
positions.
Outward Facing Sidewall:The side of an
asymmetrical tire that has a particular side that
faces outward when mounted on a vehicle.
The side of the tire that contains a whitewall, bears
white lettering, or bears manufacturer, brand,
and/or model name molding that is higher
or deeper than the same moldings on the other
sidewall of the tire.
Passenger (P-Metric) Tire:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.
Recommended Ination Pressure:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard. See
Ination - Tire Pressure on page 551andLoading
Your Vehicle on page 409.
Radial Ply Tire:A pneumatic tire in which the
ply cords that extend to the beads are laid at
90 degrees to the centerline of the tread.
Rim:A metal support for a tire and upon which
the tire beads are seated.
Sidewall:The portion of a tire between the tread
and the bead.Speed Rating:An alphanumeric code assigned
to a tire indicating the maximum speed at
which a tire can operate.
Traction:The friction between the tire and the
road surface. The amount of grip provided.
Tread:The portion of a tire that comes into
contact with the road.
Treadwear Indicators:Narrow bands, sometimes
called wear bars, that show across the tread of
a tire when only 1/16 inch (1.6 mm) of tread
remains. SeeWhen It Is Time for New Tires on
page 555.
UTQGS (Uniform Tire Quality Grading
Standards):A tire information system that
provides consumers with ratings for a tire’s
traction, temperature, and treadwear. Ratings
are determined by tire manufacturers using
government testing procedures. The ratings are
molded into the sidewall of the tire. SeeUniform
Tire Quality Grading on page 559.
Vehicle Capacity Weight:The number of
designated seating positions multiplied by 150 lbs
(68 kg) plus the rated cargo load. SeeLoading
Your Vehicle on page 409.
550

Vehicle Maximum Load on the Tire:Load on
an individual tire due to curb weight, accessory
weight, occupant weight, and cargo weight.
Vehicle Placard:A label permanently attached to
a vehicle showing the vehicle’s capacity weight
and the original equipment tire size and
recommended ination pressure. See “Tire and
Loading Information Label” underLoading
Your Vehicle on page 409.
Ination - Tire Pressure
Tires need the correct amount of air pressure to
operate effectively.
Notice:Do not let anyone tell you that
under-ination or over-ination is all right.
It is not. If your tires do not have enough air
(under-ination), you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economyIf your tires have too much air (over-ination),
you can get the following:
Unusual wear
Poor handling
Rough ride
Needless damage from road hazards
A Tire and Loading Information label is attached
to the vehicle’s center pillar (B-pillar), below the
driver’s door lock post (striker). This label lists
your vehicle’s original equipment tires and their
recommended cold tire ination pressures. The
recommended cold tire ination pressure, shown
on the label, is the minimum amount of air pressure
needed to support your vehicle’s maximum load
carrying capacity.
For additional information regarding how much
weight your vehicle can carry, and an example
of the tire and loading information label, see
Loading Your Vehicle on page 409.
When to Check
Check your tires once a month or more. Do not
forget to check the spare tire. For additional
information regarding the spare tire, seeSpare
Tire on page 588.
551

How to Check
Use a good quality pocket-type gage to check
tire pressure. You cannot tell if your tires are
properly inated simply by looking at them.
Radial tires may look properly inated even when
they’re underinated. Check the tire’s ination
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck 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.
Dual Tire Operation
When the vehicle is new, or whenever a wheel,
wheel bolt or wheel nut is replaced, check the
wheel nut torque after 100, 1,000 and 6,000 miles
(160, 1 600 and 10 000 km) of driving. For proper
torque and wheel nut tightening information, see
Removing the Spare Tire and Tools on page 566.
The outer tire on a dual wheel setup generally
wears faster than the inner tire. Your tires will wear
more evenly and last longer if you rotate the
tires periodically, seeTire Inspection and Rotation
on page 553. Also seeScheduled Maintenance
(Gasoline Engine) on page 617.
{CAUTION:
If you operate your vehicle with a tire
that is badly underinated, the tire can
overheat. An overheated tire can lose air
suddenly or catch re. You or others
could be injured. Be sure all tires
(including the spare) are properly inated.
SeeInation - Tire Pressure on page 551, for
information on proper tire ination.
552

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 555
andWheel Replacement on page 560for
more information.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, use the wheel wrench/hoist shaft to tighten
the cable. SeeChanging a Flat Tire on page 564.
If your vehicle has dual rear wheels, also see
Dual Tire Operation on page 552.The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The
rst rotation is the most important. SeeScheduled
Maintenance (Gasoline Engine) on page 617.
If your vehicle has single rear wheels and the
tread design for your front tires is the same as your
rear tires, use the rotation pattern shown here
when rotating your tires.
553