2008 SATURN ASTRA tires

Rear disc brake pads do not have
built-in brake pad wear indicators.
Periodic visual inspection of the rear
brake pads is required to determine
when to replace the pads. Visually
inspect the rear brake pads
whenever the rear wheels are
removed such as during tire rotation.
1. Set the parking brake and make
sure that the brakes have been
given enough time to cool.
2. Remove the rear wheels.
3. Visually inspect the rear brake
inner pads (C) at each rear
wheel through the inspection
window in the brake caliper (A).Brake pads should be replaced
when the inner pad (C) is
worn to 5/64 in (2 mm) of pad
thickness (B). New brake
pads, with no wear, are 25/64 of
an inch (10 mm) thick.
4. After brake pad inspection or
replacement, install the rear
wheels.Some driving conditions or climates
can cause a brake squeal when
the brakes are rst applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel bolts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel bolts in
the proper sequence to torque
specications inCapacities
and Specifications on page 10-2.
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 you make a brake stop,
the disc brakes adjust for wear.
9-24 Vehicle Service and Care
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Headlamp Aiming
The optical headlamp aiming system
has been preset at the factory
and should need no further
adjustment.
However, If the vehicle is damaged
in a crash, the headlamp aim
may be affected and adjustment
may be necessary.
If oncoming vehicles ash their high
beams at you, this may also mean
the vertical aim needs to be adjusted.
It is recommended that the vehicle
is taken to your dealer/retailer for
service if the headlamps need to be
re-aimed. It is possible however, to
re-aim the headlamps as described.The vehicle should:Be placed so the headlamps
are 25 ft. (7.6 m) from a light
colored wall.
Have all four tires on a perfectly
level surface which is level all
the way to the wall.
Be placed so it is perpendicular
to the wall.
Not have any snow, ice, or
mudonit.
Be fully assembled and all other
work stopped while headlamp
aiming is being done.
Have a full tank of fuel and
one person or 160 lbs (75 kg)
on the driver seat.
Have all tires properly inated.Headlamp aiming is done with the
vehicle’s low-beam headlamps.
The high-beam headlamps will be
correctly aimed if the low-beam
headlamps are aimed properly.
To adjust the vertical aim on
the headlamps:
1. Open the hood. SeeHood
Release on page 9-5for more
information.
2. Locate the aim dot on the lens of
the low-beam headlamp.
9-26 Vehicle Service and Care
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Fuses Usage
16Front Passenger Seat
Detection Sensor
17Tire Pressure
Monitoring
System (TPMS)/
Rain Sensor/Inside
Rearview Mirror
18 Interior Lights
21 Outside Mirror Heating
22 Sunroof
23 Rear Power Window
24Diagnostic Link
Connector
29Accessory Power
Outlet (APO)
34 Sunroof
38 Door Locks
39 Seat Heating Driver
40Seat Heating Front
PassengerTires
Your new vehicle comes with
high-quality tires made by
a leading tire manufacturer.
If you ever have questions about
the tire warranty and where to
obtain service, see the “Limited
Warranty, Maintenance and
Owner Assistance Information”
manual for details.
{CAUTION
Poorly maintained and
improperly used tires are
dangerous.
Overloading your tires can
cause overheating as a
result of too much exing.
You could have an air-out
and a serious accident.
SeeLoading the Vehicle
on page 8-30.
(Continued)
CAUTION (Continued)
Underinated tires pose
the same danger 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 tires
are cold. SeeInflation - Tire
Pressure on page 9-46.
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.
(Continued)
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CAUTION (Continued)
Worn, old tires can cause
accidents. If your tread
is badly worn, or if your
tires have been damaged,
replace them.
SeeHigh-Speed Operation
on page 9-47for ination
pressure adjustment for
high speed driving.
Low-Prole Tires
If the vehicle has 225/40ZR18
or 215/45R18 size tires, they
are classied as low-prole
performance tires. These tires
are designed for very responsive
driving on wet or dry pavement.
You may also notice more
road noise with low-prole
performance tires and that they
tend to wear faster.
Notice:If the vehicle has
low-prole tires, they are
more susceptible to damage
from road hazards or curb
impact than standard prole
tires. Tire and/or wheel
assembly damage can occur
when coming into contact with
road hazards like, potholes,
or sharp edged objects,
or when sliding into a curb.
The vehicle warranty does not
cover this type of damage.
Keep tires set to the correct
ination pressure and,
when possible avoid contact
with curbs, potholes, and
other road hazards.Winter Tires
If the vehicle has 225/40ZR18 or
215/45R18 size tires, they are
classied as low-prole performance
tires. These tires are designed for
very responsive driving on wet or dry
pavement. If you expect to drive
on snow or ice covered roads often,
you may want to get winter tires
for your vehicle. All season tires
provide good overall performance on
most surfaces but they may not
offer the traction you would like or
the same level of performance
as winter tires on snow or ice
covered roads.
Winter tires, in general, are
designed for increased traction on
snow and ice covered roads.
With winter tires, there may be
decreased dry road traction,
increased road noise, and shorter
tire tread life. After switching to
winter tires, be alert for changes in
vehicle handling and braking.
Vehicle Service and Care 9-39
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See your dealer/retailer for details
regarding winter tire availability
and proper tire selection. Also, see
Buying New Tires on page 9-54.
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 your original
equipment tires.
Winter tires with the same speed
rating as the 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.(A) Tire Size
:The tire size 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) 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.Passenger (P-Metric) Tire
Example
9-40 Vehicle Service and Care
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(D) Tire Identication Number
(TIN):The letters and numbers
following DOT (Department
of Transportation) code is 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 9-56.(G) Maximum Cold Ination
Load Limit
:Maximum load
that can be carried and the
maximum pressure needed to
support that load.
(A) Tire Ply Material
:The type
of cord and number of plies in the
sidewall and under the tread.(B) Temporary Use Only
:The compact spare tire or
temporary use tire has a tread
life of approximately 3,000 miles
(5 000 km) and should not be
driven at speeds over 50 mph
(80 km/h). The compact
spare tire is for emergency use
when a regular road tire has
lost air and gone at. If your
vehicle has a compact spare tire.
SeeCompact Spare Tire on
page 9-67andIf a Tire
Goes Flat on page 9-60.
(C) Tire Identication
Number (TIN)
:The letters and
numbers following the DOT
(Department of Transportation)
code is 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.
Compact Spare Tire Example
Vehicle Service and Care 9-41
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(D) Maximum Cold Ination
Load Limit:Maximum load that
can be carried and the maximum
pressure needed to support
that load.
(E) Tire Ination
:The
temporary use tire or compact
spare tire should be inated
to 60 psi (420 kPa). For more
information on tire pressure
and ination seeInflation - Tire
Pressure on page 9-46.
(F) Tire Size
:A combination of
letters and numbers dene a
tire’s width, height, aspect ratio,
construction type, and service
description. The letter T as
the rst character in the tire size
means the tire is for temporary
use only.(G) 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.
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 rst
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.
9-42 Vehicle Service and Care
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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
Inflation - Tire Pressure on
page 9-46andLoading
the Vehicle on page 8-30.
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 9-53.
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 9-56.Vehicle Capacity Weight
:The number of designated
seating positions multiplied
by 150 lbs (68 kg) plus the
rated cargo load. SeeLoading
the Vehicle on page 8-30.
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” under
Loading the Vehicle on
page 8-30.
Vehicle Service and Care 9-45
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