1997 CHEVROLET EXPRESS tires

Downloaded from www.Manualslib.com manuals search engine Inflation -- Tire Pressure
The CertificatiodTire label, which is on the rear edge of
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold.
“Cold” means your
vehicle has been sitting for at least three hours or driven
no more than
1 mile (1.6 lun).
NOTICE:
Don’t let anyone tell you that underinflation or
overinflation is all right. It’s not.
If your tires
don’t have enough air (underinflation), you can
get the following:
0 Too much flexing
Too much heat
Tire overloading
Bad wear
0 Bad handling
Bad fuel economy.
NOTICE: (Continued) NOTICE:
(Continued)
If your tires have too much air (overinflation),
you can get the following:
Unusual wear
0 Bad handling
0 Rough ride
0 Needless damage from road hazards.
When to Check
Check.your tires once a month or more. Also, check the
tire pressure of the spare tire.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be
sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out
dirt and moisture.
6-42

Downloaded from www.Manualslib.com manuals search engine Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 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. See “When It’s Time for New Tires” and
“Wheel Replacement” later in
this section for more
information. If your vehicle has dual rear wheels, also
see “Dual Tire Operation” later in this section.
The purpose of regular rotation is to achieve more
uniform wear for
all tires on the vehicle. The first
rotation is the most important. See “Scheduled
Maintenance Services’’
in the Index for scheduled
rotation intervals.
I FRT FRT
If your vehicle has single rear wheels, always use one of
the correct rotation patterns shown here when rotating
your tires.
If your vehicle has dual rear wheels, always use one
of
the correct rotation patterns shown here when rotating
your tires.
When you install dual wheels, be sure the vent holes in
the inner and outer wheels on each side are lined
up.

Downloaded from www.Manualslib.com manuals search engine After the tires have been rotated, adjust the front and rear
inflation pressures as shown on the Certificatioflire label.
Make certain that
all wheel nuts are properly tightened.
See “Wheel Nut Torque” in the Index.
1
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 you
need to, to get all the rust or dirt
off. (See
“Changing a Flat Tire” in the Index.) When
It’s Time
for New Tires
One way to tell when it’s
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.
Some commercial truck
tires may not have
treadwear indicators.
You need
a new tire if any of the following statements
are true:
0 You can see the indicators at three or more places
0 You can see cord or fabric showing through the
around the tire.
tire’s rubber.
0 The tread or sidewall is cracked, cut or snagged deep
enough
to show cord or fabric.
0 The tire has a bump, bulge or split.
0 The tire has a puncture, cut or other damage that
can’t be repaired well because
of the size or location
of the damage.
6-44
, , , .

Downloaded from www.Manualslib.com manuals search engine 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, see “Wheel
Nut Torque’’ in
the Index.
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.
If you’re going to be doing a lot
of driving on
high-crown roads, you can reduce tire wear by adding
5 psi (35 kPa) to the tire pressure in the outer tires. Be
sure
to return to the recommended pressures when no
longer driving under those conditions. See “Changing a
Flat Tire” in the Index for more information.
A CAUTION:
Buying New Tires
To find out what kind and size of tires you need, look at
the Certificationrnire label.
The tires installed
on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number
on each tire’s sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue
to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all-season tread
design, the TPC number will be followed by
an “MS”
(for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.
If you operate your vehicle with a tire that is
badly underinflated, the tire can overheat. An
overheated tire can lose air suddenly or catch
fire.
You or others could be injured. Be sure all
tires (including the spare) are properly inflated.

Downloaded from www.Manualslib.com manuals search engine Mixing tires could cause you to lose control while
driving.
If you mix tires of different sizes or types
(radial and bias-belted tires), the vehicle may not
handle properly, and you could have a crash.
Using tires
of different sizes may also cause
damage to your vehicle.
Be sure to use the same
size and type tires on all wheels.
1
Uniform Tire Quality Grading
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 -- A, B, C
The traction grades, from highest to lowest, are A, B, and
C, and they 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 braking (straightahead) traction tests and does not
include cornering (turning) traction.

Downloaded from www.Manualslib.com manuals search engine 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 wheels on your vehicle were aligned and balanced
carefully
at the factory to give you the longest tire life
and best overall performance. Scheduled
wheel alignment
and wheel balancing are not
needed. However, if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need
to be reset. If you notice your vehicle
vibrating when driving
on a smooth road, your wheels
may need to be rebalanced.
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
GM dealer if any of these conditions exist.
Your dealer 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 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.

Downloaded from www.Manualslib.com manuals search engine 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.
I 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.
Whenever a wheel, wheel bolt or wheel nut is replaced
on a dual wheel setup, check the wheel nut torque after
100, 1,000 and 6,000 miles (I 60, 1 600 and 10 000 km)
of driving. For proper torque, see “Wheel Nut Torque”
in the Index.
See “Changing a Flat Tire” in the Index for
more information.
Used Replacement Wheels
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been used or
how far it’s been driven. It could fail suddenly
and cause an accident.
If you have to replace a
wheel, use a new GM original equipment wheel.
6-48

Downloaded from www.Manualslib.com manuals search engine Tire Chains
NOTICE:
Use tire chains only where legal and only when
you must. Use chains that are the proper size
for your tires. Install them on the tires of the
rear axle.
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.
Appearance Care
Remember, cleaning products can be hazardous. Some
are toxic. Others can burst
into flame if you strike a
match or get them on a hot part of the vehicle. Some are
dangerous if you breathe their fumes in a closed space.
When you use anything from a container to clean your
vehicle, be sure to follow the manufacturer’s warnings
and instructions. And always open your doors or
windows when you’re cleaning the inside.
Never use these to clean your vehicle:
Gasoline
0 Benzene
0 Naphtha
Carbon Tetrachloride
Acetone
Paint Thinner
Turpentine
0 Lacquer Thinner
Nail Polish Remover
They can all be hazardous
-- some more than
others
-- and they can all damage your vehicle, too.
6-49