1997 CHEVROLET EXPRESS 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. Radiator pressure cap
B. Coolant recovery tank
C. Engine fan(s)
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 or above the FULL
COLD mark.
5-14

Downloaded from www.Manualslib.com manuals search engine 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. 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 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.

Downloaded from www.Manualslib.com manuals search 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
FULL COLD mark, add a 50/50 mixture of
dean water (preferably distilled) and DEX-COOL@
(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.
CAUTION: (Continued) 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@ coolant.
I 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.
5-16

Downloaded from www.Manualslib.com manuals search engine . . . :
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
FULL COLD 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.

Downloaded from www.Manualslib.com manuals search engine A CAUTION:
- -
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 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.

Downloaded from www.Manualslib.com manuals search engine 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
pressure cap.)
' 2. Then keep turning the pressure cap, but now push
down
as you turn it. Remove the pressure cap.
If you hear a hiss, wait for that to stop. A hiss means
there is still some pressure left.
5-19

Downloaded from www.Manualslib.com manuals search engine Engine Fan Noise
Your 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 fan is spinning slower and the clutch is not fully
engaged. This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing and/or
high outside temperatures, the fan speed increases as the
clutch more fully 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 partially disengages.
You may also hear this fan noise when you start the engine.
It will go away as the fan clutch partially 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.
5-22

Downloaded from www.Manualslib.com manuals search engine Rear Axle Engine Coolant
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
What to
Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants”
in the Index. The cooling
s stem
in your vehicle is filled with
DEX-COOL
8 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:
0 Give freezing protection down to -34°F (-37°C).
0 Give boiling protection up to 265 “F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should .