2003 CHEVROLET ASTRO Owners Manual

‘he following chart shows how much your trailer can weigh, based upon your vehicle model and options.
Two-Wheel Drive (Passenger)
Maximum trailer weight is calculated assuming the
driver and one passenger are in the tow vehicle and it
has all the required trailering equipment. The weight
of additional optional equipment, passengers and
cargo in the tow vehicle must be subtracted from the
maximum trailer weight. 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 LIH
8P7
4-34

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. 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. See
Loading Your Vehicle
on page
4-29 for more information about your vehicle’s
maximum load capacity.
A B
If you’re using a weight-carrying or a weight-distributing
hitch, the trailer tongue weight (A) should be
10 percent
to
15 percent of the total loaded trailer weight (B).
Do not exceed the maximum allowable tongue weight
for your vehicle.
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 inflated to the upper
limit for cold tires.
You’ll find these numbers on
the Certificationflire label at the rear edge of the driver’s
door or see
Loading 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.
4-35

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.
Here are some rules to follow:
If you’ll be pulling a trailer that, when loaded, will
weigh more than
2,000 Ibs. (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.
Will you have to make any holes in the body of
your vehicle when you install a trailer hitch? 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 Ibs (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:
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. Dirt and water can, too.
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. 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 fluid 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 fluid tap at the
port on the master cylinder that
sends fluid to the rear brakes. But don’t use
copper tubing for this. If you do, it will bend and
finally break
off. Use steel brake tubing.
4-36

Driving with a Trailer
If you ~ ve a rear-most window open and
you pull a trailer with your vehicle, carbon monoxide (CO) could come into your vehicle.
You can’t see or smell
CO. It can cause
unconsciousness or death. See “Engine
Exhaust” in the Index.
To maximize your safety
when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window
in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle.
Do not use
the climate control setting for maximum air because
it only recirculates the air inside
your vehicle. See “Climate Controls” in
the Index. Towing
a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be
sure the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally
to be sure that
the load
is secure, and that the lamps and any trailer
brakes are still working.
4-37

Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left.
To move the trailer to the right, move your
hand to the right. Always back up slowly and,
if possible,
have someone guide you.
Making Turns
Notice: Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns than
normal.
Do this so your trailer won’t strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have extra
wiring (included in the optional trailering package).
The arrows on your instrument panel will flash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also flash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even
if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
4-38

Driving On Grades Parking on Hills
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD
(3) or, if necessary, a lower gear
selection
if the transmission shifts too often (e.g., under
heavy loads and/or hilly conditions).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes.
If you turn your
engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating.
To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK
(P) for a
few minutes before turning the engine
off. If you do get
the overheat warning, see
Engine Overheating on
page
5-3 1.
You really shoul tot park your vehicle, ith a
trailer attached, on a hill.
If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
2. Have someone place chocks under the trailer
3. When the wheel chocks are in place, release the
4. Reapply the regular brakes. Then apply your PARK (P) yet.
wheels. regular brakes until the chocks absorb the load.
parking brake, and shift to PARK (P).
5. Release the regular brakes.
4-39

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belt, cooling system and
brake system. Each
of these is covered in this manual,
and the Index will help you find them quickly.
If you’re
trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-40

Trailer Wiring Harness
If you have the optional trailering package, your vehicle
will have an eight-wire harness, including the center
high-mounted stoplamp battery feed wire. The harness
is stored on the passenger’s side of the vehicle near
the rear wheel well. This harness has a
30 amp battery
feed wire and no connector, and should be wired by
a qualified electrical technician. After choosing an
aftermarket trailer mating connector pair, have the
technician attach one connector to the eight-wire trailer
harness and the other connector to the wiring harness
on the trailer. Be sure the wiring harness on the trailer
is
taped or strapped to the trailer’s frame rail and leave
it loose enough
so the wiring doesn’t bend or break, but
not
so loose that it drags on the ground. The eight-wire
harness must be routed out of your vehicle between
the rear door and the floor, with enough of the harness
left on both sides
so that the trailer or the body won’t
pull it. If you do not have the optional trailering
package, your vehicle will still have a trailering harness.
The harness is located near the passenger’s side
rear wheel well. It consists
of six wires that may be
used by after-market trailer hitch installers. The
technician can use the following color code chart
when connecting the wiring harness to your trailer.
e
e
Brown: Rear lamps.
Yellow: Left stoplamp and turn signal.
Dark Green: Right stoplamp and turn signal.
White (Heavy Gage): Ground.
Light Green: Back-up lamps.
White (Light Gage): Center High-Mounted Stoplamp.
Blue: Auxiliary circuit (eight-wire harness only).
Orange: Fused auxiliary (eight-wire harness only).
Store the harness in its original place. Wrap the
harness together and tie it neatly
so it won’t
be damaged.
4-4 1