cooling CHEVROLET SUBURBAN 1996 User Guide

Cooling System - Diesel Engines
When you decide it’s safe to lift the hood, here’s what you’ll see:
A. Coolant surge tank pressure cap
B. Engine fan(s)
C. Radiator
If the coolant inside the coolant surge tank is boiling, don’t do anything else
until
it cools down.
The coolant level
should be at or above
the
COLD mark. If it
isn’t,
you may have a
leak in the radiator
hoses, heater hoses,
radiator, water pump
1 or somewhere else in
the cooling system.
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NOTICE:
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 Surge Tank
NOTICE:
The diesel engine has a specific coolant fill procedure. Failur\
e to
follow this procedure could cause your engine to overheat and \
be
severely damaged.
If you haven’t found a problem yet, but the coolant level isn’t at the COLD
mark, add a 50/50 mixture of clean water (preferably distilled) and a proper
antifreeze at the coolant surge tank, but be sure the cooling system,
including the coolant surge tank pressure cap, is cool before you do it. (See
“Engine Coolant” in the Index for more information about the proper
coolant mix.)
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NOTICE:
In cold weather, water can freeze and crack the engine, radiat\
or,
heater core and other parts.
So use the recommended coolant.
1. You can remove the coolant surge tank pressure cap when the cooling
system, including the coolant surge tank pressure cap and upper
radiator hose, is no longer hot. Turn the pressure cap slowly to the left
until
it first stops. (Don’t press down while turning the pressure cap.)
If you hear a hiss, wait for that
to stop. A hiss means there is still some
pressure left.
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h
9. Then replace the
pressure cap. Be
sure the arrows
on the pressure
cap line up like
this.
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 every day
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, 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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How to Check Lubricant
P
If the level is below the bottom of the filler plug hole, you’ll need to add
some lubricant.
If the differential is at operating temperature (warm), add enough lubricant
to raise the level to the bottom of the filler plug hole.
If the differential is cold, add enough lubricant to raise the level to 1/2 inch
(I 2 mm) below 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 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.
The proper coolant for your vehicle will:
Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 262°F (128°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they should.
What to Use
Use a mixture of one-half chi? wcmr (preferably distilled) and one-half
antifreeze that meets
“GM Specification 6038-M,” which won’t damage
aluminum parts.
You can also use a recycled coolant conforming to “GM
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Specification 6038-M.” Use GM Coolant Supplement (Sealer) with a
complete coolant flush and refill. If
you use this mixture, you don’t need to
add anything else.
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 crack
the engine, radiator, heater core and other parts.
Some conditions, such
as air trapped in the cooling system, can affect the
coolant level
in the radiator. Check the coolant level when the engine is cold
and follow the steps under “Adding Coolant”
for the proper way to add
coolant.
If you have to add coolant more than four times
a year, have your dealer
check
your cooling system.
I NOTICE:
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.
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Surge Tank Pressure Cap - Diesel Engine
The surge tank
pressure cap must
be
tightly installed with
the arrows on the cap
lined up with the top
tube
of the coolant
surge tank.
NOTICE:
Your surge tank pressure cap is a unique 15 psi (105 kPa)
pressure-type cap for use with surge tank cooling systems only.
It must be tightly installed to prevent coolant
loss and possible
engine damage from overheating. Be sure the arrows on the cap
line up with the top tube of the coolant surge tank.
Thermostat
Engine coolant temperature is controlled by a thermostat in the engine
coolant system. The thermostat stops the flow
of coolant through the
radiator
until the coolant reaches a preset temperature.
When you replace your thermostat, an
AC@ thermostat is recommended.
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Air Conditioning
Every now and then have your dealership check your air conditioning
system to be sure
it has not lost any cooling ability. If you think the system
is not working properly, have your dealership check it out as soon as
possible.
The air conditioning will not work when the temperature is below
40°F
(4°C).
Fluid Leak Check
After the vehicle has been parked for a while, inspect the surface under the
vehicle for water, oil, fuel or other fluids. Water dripping from the air
conditioning system after
it has been used is normal. If you notice fuel leaks
or fumes, the causes should be found and corrected at once.
Lock Cylinders
To be sure your locks operate properly, they must be lubricated. Your
vehicle’s maintenance schedule will tell
you how often to lubricate them.
See “Recommended Fluids and Lubricants”
in the Index for the proper
lubricant to use.
You should not use penetrating oils because they could wash out the factory
installed lubricant and cause the lock
to bind. De-icers which contain
alcohol could also wash away
the lubricant, so be sure to lubricate the lock
after using
a de-icer of this type.
Battery
Every new GM vehicle has a Delco Freedom’ battery. You never have to
add water
to one of these. When it’s time for a new battery, we recommend
a Delco Freedom@ battery. Get one that has the replacement number shown
on the original battery’s label.
Vehicle Storage
If you’re not going to drive your vehicle for 25 days or more, take off the
black, negative
(-) cable from the battery. This will help keep your battery
from running down.
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I NOTICE:
The wrong wheel can also cause problems with bearing life,
brake cooling, speedometer/odometer calibration, headlamp
aim, bumper height, vehicle ground clearance, and tire
or tire
chain clearance
to the body and chassis.
Used Replacement Wheels
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Engine Identification - Diesel Engines
Engine Type
VTN Code
Fuel System
Wheel Nut Torque
MODEL
C 1500
K 1500, C-K 2500
C-K 2500
6.5L
V8
S
Turbo Diesel
DESCRIPTION
5 bolts (14mm)
6 bolts
(1 4mm)
8 bolts ( 14mm)
Cooling System Capacity
ENGINE
5.7L
6.5L
6.5L 7.4L
VIN
K
S
F
N
6.5L
V8
F
Turbo Diesel
TORQUE
120 ft. Ibs. ( 160 N*m)
120 ft. Ibs. (1 60 Nom)
I20
ft. lbs. ( 160 Nom)
QTY Without
Rear Heater*
1 7.5 Quarts
( 16.5 Liters)
23.5 Quarts (22.2 Liters)
23.5 Quarts
(22.2 Liters)
25 Quarts
(23.5
Liters)
QTY With
Rear Heater4’
20 Quarts (1 9
Liters)
27.5 Quarts (26
Liters)
27.5 Quarts (26
Liters)
27.5 Quarts (26
Li ters)
After refill. the level MUST be checked
as outlined under “Engine Cooling
System” in Section 5.
‘$All quantities are approximate.
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