engine CHEVROLET ASTRO 1996 Service Manual

If You Do Decide To Pull A Trailer
If you do, here are some important points:
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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
if your trailer will
weigh 2,000 lbs.
(900 kg) or less. You should always
use a sway control if your trailer will weigh more
than 2,000 lbs.
(900 kg). You can ask a hitch dealer
about sway controls.
Don’t tow a trailer
at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the first
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.
You should
use DRIVE (D) (or, as you need to,
a lower gear) when towing
a trailer. Operating your
vehicle in DRIVE
(D) when towing a trailer will
minimize heat buildup and extend the
life of
your transmission. 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.
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.
The following chart shows how much your trailer can
weigh, based upon your vehicle model and options.
Vehicle
Two-Wheel Drive
All-Wheel Drive
Axle Ratio Max. Trailer Wt.
3.23
3.42
3.73
3.42
3.73 4,500 lbs. (1 8 16 kg)
5,000 lbs. (2 270 kg)
5,500 lbs. (2 497 kg)
4,500 lbs.
(1 8 16 kg)
5,000 lbs. (2 270 kg)
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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:
a
a
a
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.
Driving with a Trailer
A 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’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
MAX A/C because it only recirculates the
air inside your vehicle. (See “Comfort
Controls” in the Index.)
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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.
Tbrn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have extra
wiring and a heavy-duty turn signal flasher (included
in
the optional trailering package).
The green 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 green 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.
Driving On Grades
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.
On a long uphill grade, shift down and reduce your
speed to around
45 mph (70 km/h) to reduce the
possibility
of engine and transmission overheating.
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” in
the Index.
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Parking on Hills
Youereally should not park your vehicle, with 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
PARK
(P) yet. Turn your wheels into the curb
when facing downhill and away from the curb when
facing uphill.
2. Have someone place chocks under the trailer wheels.
3, When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking
brake, and shift to PARK
(P).
5. Release the regular brakes.
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
0 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 adjustment. 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.
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I A CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use
a flashlight if
you need more light.
Be sure the battery has enough water. You’don’t
need to add water to the Delco Freedom’ battery
installed in every new
GM vehicle. But if a
battery
has filler caps, be sure the right amount
of fluid is there. If it is low, add water to take
care
of that first. If you don’t, explosive gas could
be present.
Battery fluid contains acid that can burn you.
Don’t get it on you.
If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
5. Check that the jumper cables don’t have loose or
missing insulation.
If they do, you could get a shock.
The vehicles could be damaged too.
Before you connect the cables, here are some basic
things you should
know. Positive (+) will go
to positive (+) and negative (-) will go to
negative (-) or a metal engine part. Don’t connect
positive
(+) to negative (-) or you’ll get a short that
would damage the battery
and maybe other
parts too.
Fans or other moving engine pa, can injure you
badly. Keep your hands
away from moving parts
once the engines are running.
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6. Connect the red
positive
(+) cable to the
positive
(+) terminal
of the vehicle with the
dead battery.
7. Don’t let the other
end touch metal.
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Connect it to the
positive
(+) terminal of
the good battery.
8. Now connect the black
negative
(-) cable to
the good battery’s
negative
(-) terminal.
Don’t
let the other end
touch anything
until the
next step. The other end
of the negative (-) cable
doesn’t go to the dead
battery.
It goes to a
heavy unpainted metal
part
of the vehicle with
the dead battery.
9. Attach the cable at least
18 inches (45 cm) away
from the dead battery,
but
not near engine parts
that move.
The electrical
connection is just
as
good there, but the
chance
of sparks getting
back to the battery is
much less.

10. Now start the vehicle with the good battery and run
11. Try to start the vehicle with
the dead battery. If it
the engine for a while.
won’t start after a
few tries, it probably needs service.
12. Remove the cables in reverse order to prevent
electrical shorting. Take care that they don’t
touch
each other or any other metal.
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A. Heavy Metal Engine Part
B. Good Battery
C. Dead Battery
Towing Your Vehicle
Try to have a GM dealer or a professional towing
service tow your vehicle. They can provide the right
equipment and know how to tow it without damage. See
“Roadside Assistance” in the Index.
If your vehicle has been changed or modified since
it
was factory-new by adding aftermarket items like fog
lamps, aero skirting, or special tires and wheels, these
things can be damaged during towing.
Before
you do anything, turn on the hazard
warning flashers.
When
you call, tell the towing service:
Whether your vehicle has rear-wheel drive or the
all-wheel-drive option.
That your vehicle cannot be towed from the front or
rear with sling-type equipment.
0 The make, model and year of your vehicle.
Whether you can still move the shift lever.
0 If there was an accident, what was damaged.
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Engine Overheating
You will find a temperature gage on your vehicle’s
instrument panel.
If Steam Is Coming From Your Engine
Steam from an overheated engine can burn you
badly, even if you just open the hood.
Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before
opening the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.
I NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty.
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If No Steam Is Coming From Your Engine
If you get the overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get
a little too hot when you:
0 Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. See “Driving on Grades” in
If you get the overheat warning with no sign of steam,
try this for a minute or
so:
1. If you have an air conditioner, turn it off.
the Index.
2. Turn on your heater to full hot at the highest fan
speed and open
the window as necessary.
3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D).
If you no longer have the overheat warning, you
can drive. Just
to be safe, drive slower for about
10 minutes. If the warning doesn’t come back on,
you
can drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push the accelerator until
the engine speed is about twice as fast as normal idle
speed. Bring the engine speed back
to normal idle speed
after two or three minutes. Now see if the warning stops.
But then,
if you still have the warning, turn ofthe
engine
and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.
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When you decide it’s safe to lift the hood, here’s what
you’ll see: If the coolant inside the coolant recovery tank is boiling,
don’t do anything else
until it cools down.
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Fan The
coolant level should be at
the ADD mark. If it
isn’t, you may have a leak in the radiator hoses, heater
hoses, radiator, water pump or somewhere else
in the
cooling system.
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