1998 CHEVROLET ASTRO cooling

Downloaded from www.Manualslib.com manuals search engine Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Fan
If the coolant inside the coolant recovery tank is boiling,
don’t do anything else until
it cools down. 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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Downloaded from www.Manualslib.com manuals search engine [6h, CAUTION:
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.
I NOTICE: I
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 engine cooling 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@
engine coolant at the coolant recovery tank. (See
“Engine Coolant” in the Index for more information.)
A CAUTION:
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 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 wouldn’t
get the overheat warning. Your engine could
catch fire and you
or others could be burned.
Use a
50/50 mixture of clean water and
DEX-COOL@ coolant.
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Downloaded from www.Manualslib.com manuals search engine 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 mixture. You
can be burned if you sl I 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
mixture directly
to the radiator, but be sure the cooling
system is
cool before you do it.
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Downloaded from www.Manualslib.com manuals search engine 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.
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Downloaded from www.Manualslib.com manuals search engine How to Add Coolant to the Radiator
1.
I
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
pressure cap.)
2.
If you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left. Then keep turning
the pressure cap, but now push down as you
turn
it. Remove the
pressure cap.
1 I
I 5-19

Downloaded from www.Manualslib.com manuals search engine 6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
filler neck may be lower.
If the level is lower, add
more
of the proper DEX-COOL@ coolant mixture
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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Downloaded from www.Manualslib.com manuals search engine Engine Fan Noise
This vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not
fully engaged. This
improves fuel economy and reduces fan noise. Under
heavy vehicle loading, trailer towing andor high
outside temperatures, the fan speed increases when the
clutch engages.
So you may hear an increase in fan
noise. This is normal and should not be mistaken
as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling
is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away
as the fan clutch disengages.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially
if you maintain your tires properly. If air goes
out of
a tire, it’s much more likely to leak out slowly.
But
if you should ever have a “blowout,” here are a few
tips about what to expect and what
to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off
the
accelerator pedal and grip the steering wheel firmly.
Steer
to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to
a stop -- well off the road if possible.
If
a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.
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Downloaded from www.Manualslib.com manuals search engine Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often
to check the lubricant and when to change it. See
“Scheduled Maintenance Services” in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you’ll need to add some lubricant. Add enough lubricant
to raise the level to the bottom
of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant
to use. See “Recommended Fluids and
Lubricants” in the Index.
Engine Coolant
The cooling s stem in your vehicle is filled with
DEX-COOL engine coolant. This coolant
is designed
to remain in your vehicle for
5 years or 150,000 miles
(240
000 km) whichever occurs first, if you add only
DEX-COOL’ extended 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” in
the Index.
A 50/50 mixture of water and DEX-COOL@
coolant will:
Give freezing protection down to -34°F (-37°C).
0 Give boiling protection up to 265 “F ( 129°C).
0 Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
B
they should.
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