cooling CHEVROLET C/K 2003 User Guide

5-25
4. With the coolant surge tank pressure cap off, start the
engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the engine
cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge
tank until the level reaches slightly above the
FULL mark.
5. Then replace the
pressure cap. Be
sure the pressure
cap is hand
-tight
and fully seated.

5-26
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 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 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 ªblow outº 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 ªblowout,º 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, avoid further tire and wheel damage
by driving slowly to a level place and turn on your
hazard warning flashers. The next part tells you what
to do.

6-35
Engine Coolant
If your vehicle has a Caterpillar diesel engine, the
Caterpillar Operation & Maintenance Manual provided
with your vehicle has information regarding the proper
coolant to use.
The cooling system 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 ªEngine Overheatingº in
the Index.A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 252F (122C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
NOTICE:
When adding coolant, it is important that you use
only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL 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. Damage caused by the use
of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.

6-36 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid such as 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, drinkable water
and DEX
-COOL
coolant.
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the 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.
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.

6-38
Adding Coolant
If you need more coolant, add the proper DEX
-COOL

coolant mixture at the surge tank, but only when the
engine is cool.
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 replacing the pressure cap, make sure it is
hand
-tight.
Engine Coolant (Caterpillar

Diesel Engine)
If your vehicle has a Caterpillar diesel engine, see the
Caterpillar
Diesel Engine Operation & Maintenance
Manual provided with your vehicle to find out what to
add, also when and how to service your cooling system.
Surge Tank Pressure Cap
The surge tank pressure cap
is located in the engine
compartment, on the
driver's side of the vehicle.
The surge tank pressure cap must be tightly installed.
NOTICE:
Your surge tank pressure cap is a 15 psi (103kPa)
pressure
-type cap for use with medium duty
cooling systems only. It must be tightly installed
to prevent coolant loss and possible engine
damage from overheating.

6-57 Front Wheel Bearings with Oil-Filled Hubs
If your vehicle has oil-filled
hubs, occasionally check to
see if they have enough oil.
You can tell if there is oil
there by using the circular
gage on the sight glass.
If there isn't, clean the rubber fill plug in the center of
the glass, and then remove it. Be careful not to allow
any dirt or water to get into the oil. Add enough of the
recommended oil to bring it up to the level mark that
you'll see on the glass.Refer to your Maintenance Schedule for the proper
oil to use.
When you fill the hub, check the glass again after
driving a short distance. It takes a while for the oil to
flow through the system, and you may find that you
have to add a little more to fill it to the proper level. Be
sure not to overfill the hub.
Air Conditioning System
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 GM dealer check it out as soon
as possible.

6-67
NOTICE:
The wrong wheel can cause trouble in bearing
life, brake cooling, speedometer/odometer
calibration, headlamp aim, bumper height,
vehicle ground clearance, stopping distance and
tire clearance to the body and chassis. You could
also have other problems like a tire air
-out.
Used Replacement Wheels
CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used or
how many miles it's been driven. It could fail
suddenly and cause an accident. If you have to
replace a wheel, use a new GM original
equipment wheel.
Appearance Care
Remember, cleaning products can be hazardous. Some
are toxic. Others can burst into flame if you strike a
match or get them on a hot part of the vehicle. Some are
dangerous if you breathe their fumes in a closed space.
When you use anything from a container to clean your
vehicle, be sure to follow the manufacturer's warnings
and instructions. And always open your doors or
windows when you're cleaning the inside.
Never use these to clean your vehicle:

Gasoline

Benzene

Naphtha

Carbon Tetrachloride

Acetone

Paint Thinner

Turpentine

Lacquer Thinner

Nail Polish Remover
They can all be hazardous
-- some more than
others
-- and they can all damage your vehicle, too.

6-87 Cooling System Capacity
The following approximate capacities are given in
English and metric conversions.
Please refer to ªRecommended Fluids and Lubricantsº
in the Index for more information.
C4/C5 Models Quarts (Liters). . . . . . . . . . . . . . . . .
8.1L with manual transmission 30.1 (28.5). . . . . . . .
8.1L with automatic transmission 29.8 (28.2). . . . . .
6.6L with manual transmission 27.6 (26.1). . . . . . . .
6.6L with automatic transmission 27.3 (25.8). . . . . .
C6/C7/C8 Models Quarts (Liters). . . . . . . . . . . . . .
8.1L with manual transmission 33.3 (31.5). . . . . . . .
8.1L with manual transmission,
air conditioning and increased
cooling 34.9 (33.0). . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1L with automatic transmission 32.5 (30.8). . . . . .
7.8L 200
-230 hp engine with
manual transmission 31.6 (29.9). . . . . . . . . . . . . . . .
7.8L 200
-230 hp engine with manual
transmission, air conditioning and
increased cooling 35.3 (33.4). . . . . . . . . . . . . . . . . . . C6/C7/C8 Models Quarts (Liters). . . . . . . . . . . . . .
7.8L 200
-215 hp engine with
automatic transmission 33.7 (31.9). . . . . . . . . . . . . .
7.2L 175
-230 hp engine with
manual transmission 29.3 (27.7). . . . . . . . . . . . . . . .
7.2L 175
-230 hp engine with
manual transmission, air conditioning
and increased cooling 33.0 (31.2). . . . . . . . . . . . . . .
7.2L 175
-210 hp engine with
automatic transmission 31.4 (29.7). . . . . . . . . . . . . .
7.8L 250
-275 hp engine with
manual transmission 34.9 (33.0). . . . . . . . . . . . . . . .
7.8L 250
-275 hp engine with
manual transmission, air conditioning
and increased cooling 35.4 (33.5). . . . . . . . . . . . . . .
7.8L 230
-275 hp engine with automatic
transmission 33.3 (31.5). . . . . . . . . . . . . . . . . . . . . .
7.2L 250
-300 hp engine with manual
transmission 32.8 (31.0). . . . . . . . . . . . . . . . . . . . . .
7.2L 250
-300 hp engine with manual
transmission, air conditioning and
increased cooling 33.3 (31.5). . . . . . . . . . . . . . . . . . .
7.2L 250
-300 hp engine with automatic
transmission 31.2 (29.5). . . . . . . . . . . . . . . . . . . . . .

7-6
15,000 Miles (24 000 km)

Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system.
See ªEngine Oilº in the Index. (3)(9)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(6)

DURAMAX Diesel Only: Replace fuel filter.

Steering system service. (13)

Front and rear suspension service. (14)

Spring
-to-axle U-bolts and shackle bolts
service. (16)

Exhaust system service (or every 6 months,
whichever occurs first). (3)(4)(17)

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)(46)

Parking brake service (or every 6 months, whichever
occurs first). (8)

Thermostatically controlled engine cooling fan
service. (4)(20)

Shields and underhood insulation service. (4)(5)(21)

L18/LB7 Engines Only: Clutch pedal free
travel service. (10)
20,000 Miles (32 000 km)

DURAMAX Diesel Only: Change engine oil
and filter (or every 12 months, whichever occurs
first). (2)(3)

Air compressor dry element pleated paper air strainer
service (or every 2 months or every 800 hours,
whichever occurs first).
22,500 Miles (36 000 km)

Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system.
See ªEngine Oilº in the Index. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Inspect door hinge pins and bushings and replace
as necessary.

Cooling system service. Clean the cooling system
filler cap with clean water, clean the core, pressure
test the cap and the system for proper pressure
capability and inspect condition of cooling and
heater hoses and clamps. Replace hoses if cracked,
swollen or damaged.

7-8
30,000 Miles (48 000 km) (Continued)

Wheels and tires service. (15)

Hydraulic brake service (or every 6 months,
whichever occurs first). (7)(46)

Parking brake service (or every 6 months, whichever
occurs first). (8)

C600, C700 and C800 Gasoline Engines Only:
Engine drive belts service (or every 12 months,
whichever occurs first). (18)

Thermostatically controlled engine cooling fan
service. (4)(20)

Shields and underhood insulation service. (4)(5)(21)

L18/LB7 Engines Only: Clutch pedal free
travel service. (10)
37,500 Miles (60 000 km)

Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system.
See ªEngine Oilº in the Index. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(6)

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Wheels and tires service. (15)

Parking brake service (or every 6 months, whichever
occurs first). (8)
L18/LB7 Engines Only: Clutch pedal free
travel service. (10)
40,000 Miles (64 000 km)

DURAMAX Diesel Only: Change engine oil
and filter (or every 12 months, whichever occurs
first). (2)(3)

Air compressor dry element pleated paper air strainer
service (or every 2 months or every 800 hours,
whichever occurs first).
45,000 Miles (72 000 km)

Gasoline Engine Only: Check Oil Life System.
If engine oil and filter are changed, reset system.
See ªEngine Oilº in the Index. (3)(9)

Check fluid levels (or every 3 months, whichever
occurs first). (1)(6)

DURAMAX Diesel Only: Replace fuel filter.

Chassis lubrication service (or every 6 months,
whichever occurs first). (12)

Cooling system service. Clean the cooling system
filler cap with clean water, clean the core, pressure
test the cap and the system for proper pressure
capability and inspect condition of cooling and
heater hoses and clamps. Replace hoses if cracked,
swollen or damaged.