2004 CHEVROLET ASTRO CARGO VAN Owners Manual

Certication/Tire Label
The Certication/Tire label in your vehicle will look
similar to this example.
The Certication/Tire label is found on the rear edge of
the driver’s door. The label shows the size of your
original tires and the ination pressures needed to obtain
the gross weight capacity of your vehicle.
This is called the Gross Vehicle Weight Rating (GVWR).
The GVWR includes the weight of the vehicle, all
occupants, fuel, cargo and tongue weight, if pulling
a trailer.The Certication/Tire label also tells you the maximum
weights for the front and rear axles, called Gross
Axle Weight Rating (GAWR). To nd out the actual
loads on your front and rear axles, you need to go to
a weigh station and weigh your vehicle. Your dealer can
help you with this. Be sure to spread out your load
equally on both sides of the centerline.
Never exceed the GVWR for your vehicle, or the GAWR
for either the front or rear axle.
And, if you do have a heavy load, you should spread
it out.
{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask your
dealer to help you load your vehicle the right way.
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Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
If you put things inside of your vehicle — like suitcases,
tools, packages, or anything else — they will go as
fast as the vehicle goes. If you have to stop or
turn quickly, or if there is a crash, they’ll keep going.
{CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn,
or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight evenly.
Never stack heavier things, like suitcases,
inside the vehicle so that some of them
are above the tops of the seats.
Do not leave an unsecured child restraint
in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down unless
you need to.
Payload
The Payload Capacity is shown on the Certication/Tire
label. This is the maximum load capacity that your
vehicle can carry. Be sure to include the weight of the
people inside as part of your load. If you added any
accessories or equipment after your vehicle left
the factory, remember to subtract the weight of these
things from the payload. Your dealer can help you
with this.
Trailering Package
There is a load rating which includes the weight of the
vehicle and the trailer it tows. This rating is called
the Gross Combination Weight Rating (GCWR).
When you weigh your trailer, be sure to include the
weight of everything you put in it. And, remember
to gure the weight of the people inside the vehicle as
part of your load.
Add-On Equipment
When you carry removable items, you may need to
put a limit on how many people you carry inside your
vehicle. Be sure to weigh your vehicle before you
buy and install the new equipment.
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Towing a Trailer
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. Pull a trailer only if you have
followed all the steps in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.
Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs that would
not be covered by your warranty. Always follow
the instructions in this section and check with your
dealer for more information about towing a trailer
with your vehicle.
To identify the trailering capacity of your vehicle, you
should read the information in “Weight of the Trailer”
that appears later in this section.If yours was built with trailering options, as many are,
it’s ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, acceleration, braking, durability
and fuel economy. Successful, safe trailering takes
correct equipment, and it has to be used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully
before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you’ll be driving. A good source for
this information can be state or provincial police.
Consider using a sway control. See “Hitches” later
in this section.
Don’t tow a trailer at all during the rst 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
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Then, during the rst 500 miles (800 km) that you
tow a trailer, don’t drive over 50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
See also “Driving on Grades” later in this section.
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
Tow/Haul Mode
Tow/haul is designed to assist while your vehicle is
pulling a large or heavy load or trailer. Tow/haul is
most useful while pulling such a load in rolling terrain,
in stop-and-go traffic, or when you need improved
low-speed control, such as when parking. The purpose
of the tow/haul mode is to:
Reduce the frequency and improve the predictability
of transmission shifts,
provide the same solid shift feel when pulling a
heavy load as when the vehicle is unloaded, and
improve control of vehicle speed while requiring
less throttle pedal activity.Press the button on the end of the shift lever to turn
tow/haul mode on and off. While activated, the indicator
light on the instrument panel will be on. Tow/haul
mode will turn off automatically when the ignition is
turned off. SeeTow/Haul Mode Light on page 3-34.
Tow/haul is most effective when the vehicle and trailer
combined weight is at least 75% of the vehicle’s
Gross Combined Weight Rating (GCWR). See “Weight
of the Trailer” later in this section.
Driving with tow/haul activated without a heavy load
will cause reduced fuel economy and unpleasant engine
and transmission driving characteristics, but will not
cause damage.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig.
For example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to
pull a trailer are all important. And, it can also
depend on any special equipment that you have
on your vehicle.
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The following chart shows how much your trailer can weigh, based upon your vehicle model and options.
Vehicle Axle RatioMax. Trailer Wt.
(lbs) (kg)GCWR
(lbs) (kg)
Two-Wheel Drive (Cargo)3.42
3.735,200 (2359)
5,700 (2585)9,500 (4309)
10,000 (4536)
Two-Wheel Drive (Passenger)3.42
3.734,900 (2223)
5,400 (2449)9,500 (4309)
10,000 (4536)
All-Wheel Drive (Cargo)3.42
3.735,000 (2268)
5,500 (2495)9,500 (4309)
10,000 (4536)
All-Wheel Drive (Passenger)3.42
3.734,600 (2087)
5,100 (2313)9,500 (4309)
10,000 (4536)
The Gross Combined Weight Rating (GCWR) is the
total allowable weight of the completely loaded vehicle
and trailer including any passengers, cargo equipment
and conversion. The GCWR for your vehicle should
not be exceeded.
You can ask your dealer for our trailering information
or advice, or you can write us at the address
listed in your Warranty and Owner Assistance
Information Booklet.In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
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Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total or gross weight of
your vehicle. The Gross Vehicle Weight (GVW) includes
the curb weight of the vehicle, any cargo you may carry in
it, and the people who will be riding in the vehicle. If you
have a lot of options, equipment, passengers or cargo in
your vehicle, it will reduce the tongue weight your vehicle
can carry, which will also reduce the trailer weight your
vehicle can tow. And if you will tow a trailer, you must add
the tongue load to the GVW because your vehicle will be
carrying that weight, too. SeeLoading Your Vehicle on
page 4-29for more information about your vehicle’s
maximum load capacity.The trailer tongue weight (A) should be 10 percent to
15 percent of the total loaded trailer weight, up to a
maximum of 200 lbs (92 kg) with a weight carrying
hitch. The trailer tongue weight (A) should be 10 percent
to 15 percent of the total loaded trailer weight, up to
a maximum of 750 lbs (341 kg) with a weight
distributing hitch.
After you’ve loaded your trailer, weigh the trailer
and then the tongue, separately, to see if the weights
are proper. If they aren’t, you may be able to get
them right simply by moving some items around in
the trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the upper
limit for cold tires. You’ll nd these numbers on
the Certication/Tire label at the rear edge of the
driver’s door or seeLoading Your Vehicle on page 4-29.
Then be sure you don’t go over the GVW limit for
your vehicle, including the weight of the trailer tongue.
If you use a weight distributing hitch, make sure
you don’t go over the rear axle limit before you apply
the weight distribution spring bars.
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Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads
are a few reasons why you’ll need the right hitch.
Weight-Distributing Hitches and Weight
Carrying Hitches
When using a weight-distributing hitch, the hitch
must be adjusted so that the distance (A) remains the
same both before and after coupling the trailer to the
tow vehicle.If you use a step-bumper hitch, your bumper could be
damaged in sharp turns. Make sure you have ample
room when turning to avoid contact between the trailer
and the bumper.
If you’ll be pulling a trailer that, when loaded, will weigh
more than 2,000 lbs. (900 kg.), be sure to use a
properly mounted, weight-distributing hitch and sway
control of the proper size. This equipment is very
important for proper vehicle loading and good handling
when you’re driving. You should always use a sway
control if your trailer will weigh more than these limits.
You can ask a hitch dealer about sway controls.
Will you have to make any holes in the body of your
vehicle when you install a trailer hitch?
If you’re using the wiring provided with the
factory-installed trailering package, you should not
need to make any holes in the body of your vehicle.
However, if you have an aftermarket hitch installed,
you may need to make holes in the body.
If you do, then be sure to seal the holes later when
you remove the hitch. If you don’t seal them, deadly
carbon monoxide (CO) from your exhaust can get into
your vehicle as well as dirt and water. See “Carbon
Monoxide” underEngine Exhaust on page 2-29. (A) Body to Ground Distance, (B) Front of Vehicle
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Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the
tongue of the trailer to help prevent the tongue from
contacting the road if it becomes separated from
the hitch. Instructions about safety chains may be
provided by the hitch manufacturer or by the
trailer manufacturer. Follow the manufacturer’s
recommendation for attaching safety chains and
do not attach them to the bumper. Always leave
just enough slack so you can turn with your rig.
Never allow safety chains to drag on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 lbs (450 kg)
loaded, then it needs its own brakes — and they must
be adequate. Be sure to read and follow the instructions
for the trailer brakes so you’ll be able to install, adjust
and maintain them properly.Your trailer brake system can tap into your vehicle’s
hydraulic brake system, except:
Don’t tap into your vehicle’s brake system if the
trailer’s brake system will use more than 0.02 cubic
inch (0.3 cc) of uid from your vehicle’s master
cylinder. If it does, both braking systems won’t work
well. You could even lose your brakes.
Will the trailer parts take 3,000 psi (20 650 kPa) of
pressure? If not, the trailer brake system must not
be used with your vehicle.
If everything checks out this far, then make the
brake uid tap at the port on the master cylinder
that sends uid to the rear brakes. But don’t
use copper tubing for this. If you do, it will bend
and nally break off. Use steel brake tubing.
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