service CHEVROLET ASTRO 2004 Service Manual

(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªLTº as
the ®rst two characters in the tire size means a light
truck 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 ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The letter
ªRº means radial ply construction; the letter ªDº means
diagonal or bias ply construction; and the letter ªBº
means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº. The light truck tire size example
above shows dual or single tire con®gurations.Tire Terminology and De®nitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire's height to its
width. Light Truck (LT-Metric) Tire
5-63

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. See
When It Is Time
for New Tires on page 5-69andWheel Replacement
on page 5-72for 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 ratchet/wheel wrench to tighten the cable. See
Changing a Flat Tire on page 5-75.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The ®rst rotation
is the most important. See
Part A: Scheduled
Maintenance Services on page 6-4.When rotating your tires, always use the correct rotation
patterns shown here.
Don't include the compact spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear in¯ation pressures as shown on the
Certi®cation/Tire label or Tire and Loading Information
label. See
In¯ation - Tire Pressure on page 5-66andLoading Your Vehicle on page 4-30. Make certain
that all wheel nuts are properly tightened. See
ªWheel Nut Torqueº under
Capacities and Speci®cations
on page 5-102.
5-68

Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Certi®cation/Tire label or the Tire and Loading
Information label. See
Loading Your Vehicle on
page 4-30, for examples of the labels and where they
can be found on your vehicle.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci®cation (TPC Spec)
number on each tire's sidewall. When you get new tires,
GM recommends that you get tires 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 ªMSº (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.
{CAUTION:
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. It's all right to drive with your
compact spare temporarily, it was developed
for use on your vehicle. See ªCompact Spare
Tireº in the index.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim ¯anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
5-70

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 speci®ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) 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 signi®cantly 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 speci®ed 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.
5-71

Vehicle Identi®cation
Vehicle Identi®cation Number (VIN)
This is the legal identi®er for your vehicle. It appears on
a plate in the front corner of the instrument panel, on
the driver's side. You can see it if you look through the
windshield from outside your vehicle. The VIN also
appears on the Vehicle Certi®cation and Service Parts
labels and the certi®cates of title and registration.
Engine Identi®cation
The 8th character in your VIN is the engine code. This
code will help you identify your engine, speci®cations
and replacement parts.
Service Parts Identi®cation Label
You'll ®nd this label on the front passenger door frame.
It's very helpful if you ever need to order parts. On
this label is:
·your VIN,
·the model designation,
·paint information and
·a list of all production options and special
equipment.
Be sure that this label is not removed from the vehicle.
Electrical System
Add-On Electrical Equipment
Notice:Don't add anything electrical to your
vehicle unless you check with your dealer ®rst.
Some electrical equipment can damage your vehicle
and the damage wouldn't be covered by your
warranty. Some add-on electrical equipment can
keep other components from working as they
should.
Your vehicle has an air bag system. Before attempting
to add anything electrical to your vehicle, see
Servicing Your Air Bag-Equipped Vehicle on page 1-69.
5-95

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Maintenance Requirements..............................6-2
Your Vehicle and the Environment....................6-2
How This Section is Organized.........................6-3
Part A: Scheduled Maintenance Services...........6-4
Using Your Maintenance Schedule....................6-4
Selecting the Right Schedule...........................6-5
Short Trip/City Scheduled Maintenance..............6-6
Long Trip/Highway Scheduled Maintenance......6-16
Part B: Owner Checks and Services................6-24
At Each Fuel Fill..........................................6-24
At Least Once a Month.................................6-24
At Least Twice a Year...................................6-24At Least Once a Year...................................6-25
Part C: Periodic Maintenance Inspections.........6-28
Steering, Suspension and Front Drive Axle
Boot and Seal Inspection............................6-28
Exhaust System Inspection............................6-28
Fuel System Inspection..................................6-28
Engine Cooling System Inspection...................6-28
Throttle System Inspection.............................6-29
Transfer Case and Front Axle (All-Wheel
Drive) Inspection.......................................6-29
Brake System Inspection................................6-29
Part D: Recommended Fluids and Lubricants. . . .6-30
Part E: Maintenance Record...........................6-32
Section 6 Maintenance Schedule
6-1

How This Section is Organized
This maintenance schedule is divided into ®ve parts:
ªPart A: Scheduled Maintenance Servicesºexplains
what to have done and how often. Some of these
services can be complex, so unless you are technically
quali®ed and have the necessary equipment, you
should let your GM dealer's service department do
these jobs.
Your GM dealer has GM-trained and supported
service people that will perform the work using genuine
GM parts.
{CAUTION:
Performing maintenance work on a vehicle can
be dangerous. In trying to do some jobs, you
can be seriously injured. Do your own
maintenance work only if you have the
required know-how and the proper tools and
equipment for the job. If you have any doubt,
have a quali®ed technician do the work.
If you want to get the service information, see
Service
Publications Ordering Information on page 7-11.ªPart B: Owner Checks and Servicesºtells you what
should be checked and when. It also explains what
you can easily do to help keep your vehicle in good
condition.
ªPart C: Periodic Maintenance Inspectionsºexplains
important inspections that your dealer's service
department can perform for you.
ªPart D: Recommended Fluids and Lubricantsºlists
some recommended products necessary to help
keep your vehicle properly maintained. These products,
or their equivalents, should be used whether you do
the work yourself or have it done.
ªPart E: Maintenance Recordºis a place for you to
record and keep track of the maintenance performed on
your vehicle. Keep your maintenance receipts. They
may be needed to qualify your vehicle for warranty
repairs.
6-3

Part A: Scheduled Maintenance
Services
In this part are scheduled maintenance services which
are to be performed at the mileage intervals speci®ed.
Using Your Maintenance Schedule
We at General Motors want to help you to keep
your vehicle in good working condition. But we do not
know exactly how you will drive it. You may drive
short distances only a few times a week. Or you may
drive long distances all the time in very hot, dusty
weather. You may use your vehicle in making deliveries.
Or you may drive it to work, to do errands or in many
other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You may need more
frequent checks and replacements. So please read
the following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your dealer.
This part tells you the maintenance services you should
have done and when to schedule them.When you go to your dealer for your service needs, you
will know that GM-trained and supported service
people will perform the work using GM parts.
The proper ¯uids and lubricants to use are listed in
Part D. Make sure whoever services your vehicle uses
them. All parts should be replaced and all necessary
repairs done before you or anyone else drives the
vehicle.
These schedules are for vehicles that:
·carry passengers and cargo within recommended
limits. You will ®nd these limits on the tire and
loading information label. See
Loading Your Vehicle
on page 4-30.
·are driven on reasonable road surfaces within
driving limits.
·use the recommended fuel. SeeGasoline Octane
on page 5-4
.
6-4

Selecting the Right Schedule
First you will need to decide which of the two schedules
is right for your vehicle. Here is how to decide which
schedule to follow:
Short Trip/City De®nition
Follow the Short Trip/City Scheduled Maintenance if any
one of these conditions is true for your vehicle:
·Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures
are below freezing.
·Most trips include extensive idling (such as frequent
driving in stop-and-go traffic).
·You frequently tow a trailer or use a carrier on top
of your vehicle.
·If the vehicle is used for delivery service, police,
taxi or other commercial application.
One of the reasons you should follow this schedule if
you operate your vehicle under any of these conditions
is that these conditions cause engine oil to break
down sooner.
Short Trip/City Intervals
Every 3,000 Miles (5 000 km):Engine Oil and Filter
Change (or 3 months, whichever occurs ®rst). Chassis
Lubrication (or 3 months, whichever occurs ®rst).
Drive Axle Fluid Check.
Every 6,000 Miles (10 000 km):Tire Rotation.
Every 15,000 Miles (25 000 km):Engine Air Cleaner
Filter Inspection. Front Wheel Bearing Repack
(two±wheel drive only) (or at each brake relining,
whichever occurs ®rst). Automatic Transmission Service
(severe conditions only).
Every 30,000 Miles (50 000 km):Engine Air Cleaner
Filter Replacement. Fuel Filter Replacement.
Every 50,000 Miles (83 000 km):Automatic
Transmission Service (normal conditions). Transfer
Case Fluid Change.
Every 100,000 Miles (166 000 km):Spark Plug Wire
Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150 000 Miles (240 000 km):Cooling System
Service (or every 60 months, whichever occurs
®rst). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
6-5

Long Trip/Highway De®nition
Follow this scheduled maintenanceonlyif none of the
conditions from the Short Trip/City Scheduled
Maintenance are true. Do not use this schedule if the
vehicle is used for trailer towing, driven in a dusty area
or used off paved roads. Use the Short Trip/City
schedule for these conditions
Driving a vehicle with a fully warmed engine under
highway conditions will cause engine oil to break down
slower.
Long Trip/Highway Intervals
Every 7,500 Miles (12 500 km):Engine Oil and Filter
Change (or every 12 months, whichever occurs
®rst). Chassis Lubrication (or 12 months, whichever
occurs ®rst). Drive Axle Fluid Check. Tire Rotation.
Every 15,000 Miles (25 000 km):Engine Air Cleaner
Filter Inspection. Automatic Transmission Service
(severe conditions only).
Every 30,000 Miles (50 000 km):Fuel Filter
Replacement. Engine Air Cleaner Filter Replacement.
Front Wheel Bearing Repack (two±wheel drive only) (or
at each brake relining, whichever occurs ®rst).
Every 50,000 Miles (83 000 km):Automatic
Transmission Service (normal conditions). Transfer
Case Fluid Change.Every 100,000 Miles (166 000 km):Spark Plug Wire
Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150,000 Miles (240 000 km):Cooling System
Service (or every 60 months, whichever occurs
®rst). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
Short Trip/City Scheduled
Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same interval
after 150,000 miles (240 000 km) for the life of this
vehicle.
See
Part B: Owner Checks and Services on page 6-24andPart C: Periodic Maintenance Inspections on
page 6-28.
6-6