2004 CHEVROLET ASTRO cooling

To close the rear doors, close the driver's side door
®rst. Check to make sure both doors are completely
closed.
The rear doors have a check assembly to keep the
doors from opening beyond 90 degrees.
To fully open the rear
doors, push in on the clip
and lift the check
assembly up off the
mounting bracket.
Do this on each door. Replace the check assemblies on
the mounting brackets before closing the doors.
{CAUTION:
It can be dangerous to drive with the rear
glass open because carbon monoxide (CO)
gas can come into your vehicle. You can not
see or smell CO. It can cause
unconsciousness and even death. If you must
drive with the rear glass open or if electrical
wiring or other cable connections must pass
through the seal between the body and the
rear glass:
·Make sure all other windows are shut.
·Turn the fan on your heating or cooling
system to its highest speed and select the
control setting that will force outside air
into your vehicle. See
Climate Control
System on page 3-16.
·If you have air outlets on or under the
instrument panel, open them all the way.
See
Engine Exhaust on page 2-28.
2-12

Climate Controls
Climate Control System
With this system you can control the heating, cooling
and ventilation for your vehicle.
Turn the right knob clockwise or counterclockwise to
direct the air¯ow inside of your vehicle.To change the current mode, select one of the following:
)(Bi-Level):This mode directs approximately half
of the air to the instrument panel outlets and directs
most of the remaining air to the ¯oor outlets. Some air
may be directed toward the windshield.
H(Vent):This mode directs air to the instrument
panel outlets.
6(Floor):This mode directs most of the air to the
¯oor outlets with some air directed to the outboard
outlets (for the side windows) and some air directed to
the windshield.
A/C (Air Conditioning):This setting brings in outside
air, cools and dehumidi®es it.
MAX A/C (Maximum Air Conditioning):This setting
cools the air the fastest, by recirculating the inside air.
The right knob can also be used to select the defrost
mode. Information on defogging and defrosting can be
found later in this section.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan speed.
Temperature Control:Turn the center knob clockwise
or counterclockwise to increase or decrease the
temperature inside your vehicle.
3-18

If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that can make
your trips safer and more enjoyable.
·Keep your vehicle in good shape. Check all ¯uid
levels and also the brakes, tires, cooling system
and transmission. These parts can work hard
on mountain roads.
·Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when you go
down a steep or long hill.
{CAUTION:
If you do not shift down, your brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let your engine assist your brakes on a
steep downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. They could
get so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Always
have your engine running and your vehicle in
gear when you go downhill.
·Know how to go uphill. You may want to shift down to
a lower gear. The lower gears help cool your engine
and transmission, and you can climb the hill better.
·Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at speeds
that let you stay in your own lane.
·As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled car or
an accident.
·You may see highway signs on mountains that
warn of special problems. Examples are long
grades, passing or no-passing zones, a falling rocks
area or winding roads. Be alert to these and take
appropriate action.
4-23

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You can not see or smell CO. It can cause
unconsciousness or death. See
Engine
Exhaust on page 2-26
. 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 Control System
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.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.
4-41

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 ¯uid (don't over®ll),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you ®nd 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.
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 quali®ed 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-wireharness must be routed out of your vehicle between the
rear door and the ¯oor, 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.
·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.
4-44

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood.....................5-9
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Cover...............................................5-17
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-27
Engine Overheating.......................................5-28
Cooling System............................................5-30
Engine Fan Noise.........................................5-36
Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
All-Wheel Drive..............................................5-47
Rear Axle.......................................................5-48
Front Axle......................................................5-48
Bulb Replacement..........................................5-49
Halogen Bulbs..............................................5-49
Headlamps..................................................5-50
Front Turn Signal Lamps...............................5-53
Taillamps.....................................................5-54
Replacement Bulbs.......................................5-55
Windshield Wiper Blade Replacement..............5-56
Tires..............................................................5-56
In¯ation - Tire Pressure.................................5-66
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-69
Buying New Tires.........................................5-70
Uniform Tire Quality Grading..........................5-71
Wheel Alignment and Tire Balance..................5-72
Wheel Replacement......................................5-72
Tire Chains..................................................5-74
If a Tire Goes Flat........................................5-74
Changing a Flat Tire.....................................5-75
Compact Spare Tire......................................5-86
Section 5 Service and Appearance Care
5-1

How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission ¯uid to use. SeePart D:
Recommended Fluids and Lubricants on page 6-30.
Using a funnel, add ¯uid down the transmission dipstick
tube only after checking the transmission ¯uid while it
is hot. (A cold check is used only as a reference.) If the
¯uid level is low, add only enough of the proper ¯uid
to bring the level up to the HOT area for a hot check. It
doesn't take much ¯uid, generally less than one pint
(0.5 L).
Don't over®ll.
Notice:We recommend you use only ¯uid labeled
DEXRONž-III, because ¯uid with that label is
made especially for your automatic transmission.
Damage caused by ¯uid other than DEXRON
ž-III is
not covered by your new vehicle warranty.
·After adding ¯uid, recheck the ¯uid level as
described under²How to Check.²
·When the correct ¯uid level is obtained, push the
dipstick back in all the way; then ¯ip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see
Engine Overheating on
page 5-28.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOLžmay
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs ®rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
ž(silicate-free) coolant in your vehicle.
5-25

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOLžcoolant which won't damage
aluminum parts. If you use this coolant mixture,
you don't need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle's coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch ®re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and the proper coolant.
Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
Checking Coolant
The engine coolant tank is
located in the engine
compartment on the
passenger's side at the
front. See
Engine
Compartment Overview on
page 5-12
for more
information on location.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at ADD, or a
little higher. When your engine is warm, the level
should be up to FULL HOT, or a little higher.
5-26