GMC SIERRA DENALI 2003 Owners Manual

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 or above the
FULL COLD mark, add
a
50/50 mixture of clean, drinkable waterand
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 Engine
Coolant on
page 5-24 for more information.
/;1 CAUTIC I:
Steam and scaldin, ,iquids from a hot coa ....g
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) 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.
5-32

Adding ~.ly p.-.n water to your coa....g 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 i i 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.
I
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.
5-33

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.
2. 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.
3. Then keep turning the pressure cap slowly, and
remove
it.
5-34

4. Then fill the coolant surge tank with the proper
mixture, to the FULL COLD mark. 5. 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 the FULL COLD mark.
5-35

6. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated. 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 disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-36

Power Steering Fluid
When to Check Power Steering Fluid
It is not necessary to regularly check power steering fluid
unless you suspect there is a leak in the system or
you hear an unusual noise. A fluid loss in this system
could indicate a problem. Have the system inspected
and repaired. See
Engine Compartment Overview
on page
5-12 for reservoir location.
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at the fluid level on the dipstick.
The level should be at the
FULL COLD mark.
If necessary, add only enough fluid to bring the
level up to the mark.
What to Use
To determine what kind of fluid to use, see Part Dr
Recommended Fluids and Lubricants on page 6- 16.
Always use the proper fluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
5-37

Windshield Washer Fluid
What to Use
When you need windshield washer fluid, be sure to read
the manufacturer’s instructions before use. If you will
be operating your vehicle in an area where the
temperature may fall below freezing, use a fluid that
has sufficient protection against freezing. See
Engine
Compartment Overview
on page 5-12 for reservoir
location.
Adding Washer Fluid
Open the cap with the
washer symbol on it.
Add washer fluid until
the tank is full.
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.
5-38

Brake Fluid
Your brake master cylinder reservoir is filled with DOT-3
brake fluid. See
Engine Compantment Overview on
page
5-12 for the location of the reservoir.
There are only two reasons why the brake fluid level
in the reservoir might go down. The first is that the brake
fluid goes down to an acceptable level during normal
brake lining wear. When new linings are put in, the fluid
level goes back
up. The other reason is that fluid is
leaking out of the brake system.
If it is, you should have
your brake system fixed, since a leak means that
sooner or later your brakes won’t work well, or won’t
work at all.
So, it isn’t a good idea to “top off your brake fluid.
Adding brake fluid won’t correct a leak.
If you add fluid
when your linings are worn, then you’ll have too much
fluid when you get new brake linings. You should add (or
remove) brake fluid, as necessary, only when work is
done
on the brake hydraulic system.
If yo, ..rave 1,- _._____ rake ---id, it ~~-1 spill on
the engine. The fluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
Refer to the Maintenance Schedule to determine when
to check your brake fluid. See
Part C: Periodic
Maintenance Inspections on page 6-14.
5-39

Checking Brake Fluid
You can check the brake fluid without taking off the cap.
What to Add
When you do need brake fluid, use only DOT-3 brake
fluid.
Use new brake fluid from a sealed container
only. See
Part Dr Recommended Fluids and Lubricants
on
page 6- 16.
Just look at the brake fluid reservoir. The fluid level
should be above
MIN. If it isn’t have your brake system
checked to see
if there is a leak. Always
clean the brake fluid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
With the wrong kind
of fluid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake fluid.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over the
MAX mark.
5-40

Notice:
Using the wrong fluid can badly damage brake
system parts. For example, just a few drops of
mineral-based
oil, such as engine oil, in your
brake system can damage brake system
parts
so badly that they’ll have to be replaced.
Don’t let someone
put in the wrong kind of fluid.
If you spill brake fluid on your vehicle’s painted
surfaces, the paint finish can be damaged.
Be careful not to spill brake fluid on your
vehicle.
If you do, wash it off immediately.
See “Appearance Care” in the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal firmly). The
brake wear warning sound means that soon
your brakes won’t work well. That could lead to
an accident. When you hear the brake wear
Notice: Continuing to drive with worn-out brake
pads could result
in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are first applied or lightly applied.
This does not mean something is wrong with your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence
to GM torque specifications.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6- 15
5-41