1993 CHEVROLET ASTRO PASSENGER Owners Manual

Downloaded from www.Manualslib.com manuals search engine A Poorly maintained and improperly used tires are dangerous. Overloading your 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” in the Index.
Underinflated tires pose the same danger as overloaded tires.
The resulting accident could cause serious injury. Check all ti\
res
frequently to maintain the recommended pressure. Tire pressure
should be checked when the tires are cold.
Overinflated tires are more likely to be cut, punctured, or broken
by sudden impact (as when you hit a pothole). Keep tires at\
the recommended pressure.
Worn, old tires can cause accidents.
If your tread is badly worn,
or
if your tires have been damaged, replace them.
Don’t drive over
85 mph (1 35 km/h) even if it’s legal, unless you
have the correct high speed rated tires.
Inflation-Tire Pressure
The Certification/Tire 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 a mile.
6-45

Downloaded from www.Manualslib.com manuals search engine Senrice & Appearance Care
on’t let anyone tell you that underinflation or overinflation is all right. It’s
When to Check: Check your tires once a month or more. Don’t forget your
compact spare tire.
It should be at 60 psi (420 kPa).
How to Check: Use a good quality pocket-type gage to check tire pressure.
Simply looking at the tires will not tell you the pressure, e\
specially
if you
have radial tires-which may look properly inflated even
if they’re
underinflated.
If your tires have valve caps, be sure to put them back on. They help
prevent leaks by keeping out dirt and moisture.
6-46

Downloaded from www.Manualslib.com manuals search engine Tire Inspection and Rotation
To make your tires last longer, have them inspected and rotated a\
t the
mileages recommended in the Maintenance Schedule. See “Scheduled
Maintenance Services” in the Index.
Use this rotation pattern.
If your vehicle has front tires with different load ratings or tread designs (such
as all season vs. on/off road) than the rear tires, don’t \
rotate your tires front
to rear.
After the tires have been rotated, adjust the front and rear inflation pressure
as shown on the CertificationRire label. Make certain that all wheel nuts are
properly tightened. See “Wheel Nut Torque” in the Index.
CAUTION I
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 an\
y
- - .-..-rust. -o,r dit-.from places where the wheel attaches to the vehicle. In
an emergency, you can use a cloth or 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.)
I
6-47

Downloaded from www.Manualslib.com manuals search engine Sewice & Appearance Cam
When lt3 Time for New Tires
K1656
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
2/32 inch (1.6 mm) or
less of tread remaining.
You need a new tire
if:
You can see the indicators at three 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
The tire has a bump, bulge or split.
cord
or fabric.
The tire has a puncture, cut, or other damage that can’t be repaired
because of the size or location of the damage.
Buying New Tires
To find out what kind and size of tires you need, look at the CertificationRire
label. The tires installed on your vehicle when
it was new had a Tire
Performance Criteria Specification (TPC Spec) number on each t\
ire’s sidewall.
When you get new tires, get ones with that same TPC Spec num\
ber. That
way, your vehicle will continue to have tires that are designed to give proper
endurance, handling, speed rating, traction, ride and other thin\
gs during normal service on your vehicle. If your tires have an all-season tread design,
the
TPC number will be followed by a “MS” (for mud and snow).
6-48

Downloaded from www.Manualslib.com manuals search engine 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 an\
d construction
type (bias, bias-belted
or radial) as your original tires.
A
Mixing tires could cause you to lose control while driving. If you mix
tires
of different sizes or types (like radial and bias-belted tires) the
vehicle may not handle properly, and you could have a crash. Be
sure
to use the same size and type tires on all wheels. I
It’s all right to drive with your compact spare, though. It was developed for
limited use on your vehicle.
Uniform Tire Quality Grading
The following information relates to the system developed by the United
States National Highway Traffic Safety Administration which grade\
s tires by
treadwear, traction and temperature performance. (This applies o\
nly
to
vehicles sold in the United States.)
Treadwear
The treadwear grade is a comparative rating based on the wear \
rate of the
tire when tested under controlled conditions on a specified governmen\
t test
course.
For example, a tire graded 150 would wear one and a half (142)
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 var\
iations in
driving habits, service practices and differences in road charac\
teristics and
climate.
Traction-A, B, C
The traction grades, from highest to lowest are: A, B, and C. 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
(straight-ahead) traction tests and does not include cornering \
(turning) traction.
Temperatur+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 laborat\
ory 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
6-49

Downloaded from www.Manualslib.com manuals search engine 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, underinfla\
tion,
or
excessive loading, either separately or in combination, can cause heat buildup
and possible tire failure.
These grades are molded on the sidewalls of passenger car tire\
s.
While the tires available as standard
or optional equipment on General Motors
vehicles may vary with respect to these grades, all such tires meet General
Motors performance standards and have been approved for use on \
General
Motors vehicles.
All passenger type (P Metric) tires must conform to Federal
safety requirements in addition to these grades.
Wheel Alignment and lire Balance
The wheels on your vehicle were aligned and balanced carefully \
at the
factory to give you the longest tire life and best overall pe\
rformance.
In most cases, you will not need
to have your wheels aligned again.
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. If wheel nuts keep
coming loose the wheel, wheel
bolts, and wheel nuts should be replaced. If
the wheel leaks air out, replace it (except some aluminum whe\
els, which can
sometimes be repaired). See your GM dealer if any of these c\
onditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load carrying capacity dia\
meter, 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 you have the right wheel, wheel bolts, and wheel nuts\

for your
vehicle.
6-50

Downloaded from www.Manualslib.com manuals search engine CAUTION
I
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 I
The wrong wheel can also cause problems with bearing life, bra\
ke cooling, speedometer/odometer calibration, headlight aim, bumper height, vehiclc
ground clearance, and tire
or tire chain clearance to the body and chassi I
Used Replacement Wheels
Putting a used wheel on your vehicle is dangerous. You can’t know
how it’s been used or how many miles it’s been driven. It could fail
suddenly and cause an accident.
If you have to replace a wheel use
1 a new GM original equipment wheel.
Tire Chains
f your vehicle has PqA
iamage your vehicle
f you have other size tires, use tire chains only when you ... st. se on
SAE Class “S” type chains that are the proper size for your tires. lnst
hem on the rear axle tires and tighten them
as tightly as PO
he ends securely fastened. Drive slowly and follow the chain
nanufacturer’s instructions.
If you can hear the chains contacting your
rehicle, stop and retighten them.
If the contact continues, slow d8
t stops. Driving too fast with chains on will damage your vehicle.
6-5 1

Downloaded from www.Manualslib.com manuals search engine