2003 CHEVROLET C/K coolant level

3-4
(Bi-Level Air Conditioning): This setting divides
airflow between the floor vents and instrument panel
vents. The air conditioning compressor will cycle
continuously in this setting as long as the outside air
temperature is warm enough to activate the compressor.
(Vent): This setting directs air through the
instrument panel vents.
(Floor): This setting directs air through the
floor vents.
(Defog): This setting divides airflow between the
floor vents and windshield vents.
(Defrost): This setting directs air through the
windshield vents. This setting is used to remove fog or
ice from the windshield.
Air Conditioning (If Equipped)
Before using the air conditioning, open the windows to
clear the vehicle of hot air. This reduces the time it takes
for your vehicle to cool down. Then keep your windows
closed for the air conditioner to work at its best.You can use maximum air conditioning with the
temperature knob in the blue area when it's really hot
outside and you need to cool the inside air quickly.
Maximum air conditioning lets in only a little air from
the outside.
If you first use maximum air conditioning, you can then
use regular air conditioning with the temperature knob
in the blue area, as soon as the vehicle has cooled down,
so outside air will be going through your vehicle.
While in maximum air conditioning, regular air
conditioning, bi
-level air conditioning, defog or defrost
mode, you may notice a slight increase or decrease in
engine speed, due to compressor operation. This is
normal because the system is designed to cycle the
compressor on and off to maintain the desired
temperature.
Heating
On cold days, use floor with the temperature knob in the
red area. Outside air will be brought in, heated and
distributed through the floor vents. The heater works
best if you keep your windows closed while using it.
If you use the optional engine coolant heater before
starting your engine, your heating system will produce
warmer air faster to heat the passenger compartment in
cold weather. See ªEngine Coolant Heaterº in the Index.

5-20
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Engine Fan
B. Coolant Surge Tank
If your vehicle has a Caterpillar diesel engine, see the
Caterpillar

Diesel Engine Operation and Maintenance
Manual provided with your vehicle.If the coolant inside the coolant surge tank is boiling,
don't do anything else until it cools down. The vehicle
should be parked on a level surface.
The coolant level
should be at COLD
FILL or higher. If it
isn't, you may have a
leak at the pressure cap
or in the radiator
hoses, heater hoses,
radiator, water pump
or somewhere else in
the cooling system.

5-22 How to Add Coolant to the Coolant
Surge Tank
If you haven't found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level isn't at COLD FILL or higher, add
a 50/50 mixture of clean, drinkable water and
DEX
-COOL
coolant 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 ªEngine
Coolantº in the Index for more information.
If no coolant is visible in the surge tank, add coolant
as follows:
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 coolant
surge tank pressure cap
-- even a little -- they
can come out at high speed.
CAUTION: (Continued)
CAUTION: (Continued)
Never turn the cap when the cooling system,
including the coolant surge tank pressure cap, is
hot. Wait for the cooling system and coolant
surge tank pressure cap to cool if you ever have
to turn the pressure cap.

5-23
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:
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.
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.
1. Park the vehicle on a level surface. 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 counterclockwise (left) about
one full turn. If you hear a hiss, wait for that to stop.
A hiss means there is still some pressure left.

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.

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-4 Fuel (Gasoline Engine)
6
-5 Diesel Fuel Requirements and Fuel System
6
-15 Fuels in Foreign Countries (Gasoline Engines)
6
-15 Filling Your Tank
6
-17 Filling a Portable Fuel Container
6
-18 Checking Things Under the Hood
6
-20 Noise Control System
6
-21 Engine Oil (Gasoline Engines)
6
-27 Engine Oil (Caterpillar
Diesel Engines)
6
-27 Engine Oil (DURAMAX Diesel)
6
-30 Engine Air Cleaner/Filter
6
-32 Automatic Transmission Fluid
6
-32 Manual Transmission Fluid
6
-34 Rear Axle
6
-34 Rear Axle Shift Motor (Option)
6
-35 Engine Coolant
6
-38 Engine Coolant (Caterpillar
Diesel Engine)6
-38 Surge Tank Pressure Cap
6
-39 Power Steering Fluid
6
-40 Windshield Washer Fluid
6
-41 Brakes
6
-52 Battery
6
-54 Other Service Items
6
-58 Tires
6
-67 Appearance Care
6
-68 Cleaning the Inside of Your Vehicle
6
-71 Cleaning the Outside Your Vehicle
6
-75 GM Vehicle Care/Appearance Materials
6
-76 Vehicle Identification Number (VIN)
6
-76 Service Statement
6
-77 Service Parts Identification Label
6
-77 Electrical System
6
-86 Capacities and Specifications
6
-90 Normal Maintenance Replacement Parts

6-37 Checking Coolant
The coolant surge tank is located in the engine
compartment on the driver's side of the vehicle.
CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
Never turn the surge tank pressure cap
-- even a
little
-- when the engine and radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the COLD
FILL mark or higher.
If the low coolant light
comes on and stays on,
it means you're low on
engine coolant.
See ªLights, Low Coolant Warning Lightº in the Index
for further information.

6-41
NOTICE:

When using concentrated washer fluid,
follow the manufacturer's instructions for
adding water.

Don't mix water with ready
-to-use washer
fluid. Water can cause the solution to freeze
and damage your washer fluid tank and
other parts of the washer system. Also,
water doesn't clean as well as washer fluid.

Fill your washer fluid tank only
three
-quarters full when it's very cold.
This allows for expansion if freezing occurs,
which could damage the tank if it is
completely full.

Don't use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.
Brakes
Brake Fluid
If your vehicle has hydraulic brakes, there's a brake
master cylinder. Refer to the Maintenance Schedule to
determine when to check your brake fluid.
CAUTION:
Don't add brake fluid before you check the level.
If you do, you could get too much brake fluid.
Brake fluid could spill on the hot engine and it
can catch fire. You could be burned and your
vehicle could be damaged. See ªChecking Brake
Fluidº in this section.