radiator CHEVROLET ASTRO 1996 Owners Manual

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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Heater and radiator hoses, and other engine
parts, can be
very hot. Don’t touch them. If you
do, you can be burned.
Don’t run the engine if there is a leak.
If you run
the engine, it could lose
all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
Engine damage from running your engine without coolant isn’t covered by your warranty.
If there seems to be
no leak, start the engine again. See
if the fan speed increases when idle speed
is doubled by
pushing the accelerator pedal down.
If it doesn’t, your
vehicle needs service. Turn off the engine.
How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the
ADD mark, add a 50/50 mixture of clean
water (preferably distilled) and DEX-COOL TM
(orange-colored, silicate-free) antifreeze at the coolant
recovery tank. (See “Engine Coolant’’
in the Index for
more information.)
Adding only plain water to your cooling system
can be dangerous. Plain water,
or some other
liquid like alcohol, can boil before the proper
coolant mix
will. Your vehicle’s coolant warning
system is set
for the proper coolant mix. With
plain water or the wrong mix, your engine could
get too hot but you wouldn’t get the overheat
warning. Your engine could catch fire and you or
others could be burned. Use a
50/50 mix of clean
water and
DEX-COOL TM antifreeze.
5-16

NOTICE:
In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts. Use the recommended coolant and the proper
coolant mix.
I A CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn
if the engine parts are hot
enough. Don’t spill coolant on
a hot engine.
When the coolant in
the coolant recovery tank is at the
ADD mark, start your vehicle.
If the overheat warning continues, there’s one more
thing
you can try. You can add the proper coolant mix
directly
to the radiator, but be sure the cooling system is
cool before you do
it.

Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure, and if you turn the radiator
pressure cap
-- even a little -- they can come out
at high speed. Never turn the cap when the
cooling system, including the radiator pressure
cap,
is hot. Wait for the cooling system and
radiator pressure cap to cool if you ever have to
turn the pressure cap.

How to Add Coolant to the Radiator
1. You can remove the
radiator pressure cap
when the cooling
system, including the
radiator pressure cap and
upper radiator hose, is
no longer hot. Turn the
pressure cap slowly
counterclockwise until it
first stops. (Don't press
down while turning the
If
you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left.
I 2. Then keep turning
I ,the pressure cap, but
now push down as you
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I
I
3. Fill the radiator with the proper mix, up to the base -
of the filler neck.
4. Then fill the coolant recovery tank to the ADD mark.
5. Put the cap back on the coolant recovery tank, but
leave the radiator pressure cap off.

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine fan.
filler neck may be lower.
If the level is lower, add
more of the proper
mix through the filler neck until
the level reaches the base of the filler neck.
7. By this time the coolant level inside the radiator
8. Then replace the pressure cap. At any time during
this procedure
if coolant begins to flow out of the
filler neck, reinstall the pressure cap. Be sure the
arrows on the pressure cap line up like this.
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NOTICE:
When adding coolant it is important that you use
DEX-COOL
TM (orange-colored, silicate-free)
coolant meeting
GM Specification 6277M.
If silicated coolant is added to the system,
premature engine, heater core or radiator
corrosion may result. In addition, the engine
coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first.
What to Use
Use a mixture
of one-half clean water (preferably
distilled) and one-half
DEX-COOL (orange-colored,
silicate-free) antifreeze that meets GM Specification
6277M, which won’t damage aluminum parts. Use GM
Engine Coolant Supplement (sealer)
(GM Part
No. 3634621) with any complete coolant change. If you
use this mixture, you don’t need to add anything else.
A CAUTION:
I
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like alcohol, can boil before the proper
coolant mix will. Your vehicle’s coolant warning
system is set for the proper coolant mix. With
plain water or the wrong mix, your engine could
get too hot but
you wouldn’t get the overheat
warning. Your engine could catch fire and you or
others could be burned. Use
a 50/50 mix of clean
water and DEX-COOL (orange-colored,
silicate-free) antifreeze.
6-26

NOTICE:
If you use an improper coolant mix, your engine
could overheat and be badly damaged. The repair
cost wouldn’t be covered by your warranty. Too
much water in the mix can freeze and crackthe
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.
I NOTICE: I
If you use the proper coolant, you don’t have to
add extra inhibitors or additives which claim
to
improve the system. These can be harmful.
Checking Coolant
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.
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Adding Coolant If ,you need more coolant, add the proper mix
at the
Add coolant mix at the recovery tank, but be,careful not
to spill it.
' A CAUTION:
Turnj J the radiator pressure cap when the
engine.and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
With the'coolant recovery tank, you will almost
never have
to add coolant at the radiator.
Never turn the radiator pressure cap
-- even a
1. little -- when,the engine and radiator are hot. I
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
.
and it will burn if the engine parts are hot
enough. Don't spill coolant on
a hot engine.
6-28