CHEVROLET SILVERADO 2007 1.G Owners Manual

Cooling System
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan
{CAUTION:
An electric engine cooling fan can start
even when the engine is not running.
To avoid injury, always keep hands,
clothing, and tools away from any engine
cooling fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
Check the coolant level after the system cools
down. Some amount of coolant may be lost due to
overheating.
5.3L Engine (4.3L, 4.8L and 6.0L Similar)
521

The coolant level should be at or above the FULL
COLD mark. If it is not, 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.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not touch
them. If you do, you can be burned.
Do not run the engine if there is a leak. If
you run the engine, it could lose all
coolant. That could cause an engine re,
and you could be burned. Get any leak
xed before you drive the vehicle.
Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode (V8 Engines Only) on page 520
for information on driving to a safe place in an
emergency.
522

Notice:Using coolant other than DEX-COOL®
may cause premature engine, heater core, or
radiator corrosion. In addition, the engine
coolant could require changing sooner, at
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
How to Add Coolant to the Coolant
Surge Tank for Gasoline Engines
If your vehicle has a diesel engine, see “Cooling
System” in the DURAMAX®Diesel Supplement for
the proper coolant ll procedure.
If you have not found a problem yet, check to see
if coolant is visible in the surge tank. If coolant
is visible but the coolant level is not at or above the
FULL COLD mark, 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. SeeEngine
Coolant on page 514for 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. 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.
523

{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 would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and a proper 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. Do not spill
coolant on a hot engine.
1. 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
about one full turn. If you hear a hiss, wait
for that to stop. A hiss means there is
still some pressure left.
524

2. Then keep turning the pressure cap slowly,
and remove it.
3. Fill the coolant surge tank with the proper
mixture, to the FULL COLD mark.4. With the coolant surge tank pressure cap off,
start the engine and let it run until the engine
coolant temperature gage indicates
approximately 195°F (90°C).
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. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
6. Verify coolant level after engine is shut off
and the coolant is cold. If necessary, repeat
coolant ll procedure Steps 1 through 6.
525

Engine Fan Noise
If 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.If your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling
is required. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, or if you
are operating your air conditioning system, the fans
may change to high speed and you may hear an
increase in fan noise. This is normal and indicates
that the cooling system is functioning properly. The
fans will change to low speed when additional
cooling is no longer required.
Power Steering Fluid
SeeEngine
Compartment Overview
on page 500for
reservoir location.
526

When to Check Power Steering Fluid
It is not necessary to regularly check power
steering uid unless you suspect there is a leak in
the system or you hear an unusual noise. A
uid loss in this system could indicate a problem.
Have the system inspected and repaired.
How to Check Power Steering Fluid
To check the power steering uid, do the following:
1. Turn the key off and let the engine
compartment cool down.
2. Wipe the cap and the top of the reservoir
clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the
uid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough uid to bring the level
up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 639.
Always use the proper uid. Failure to use the
proper uid can cause leaks and damage hoses
and seals.
Windshield Washer Fluid
What to Use
When windshield washer uid needs to be added,
be sure to read the manufacturer’s instructions
before use. Use a uid that has sufficient
protection against freezing in an area where the
temperature may fall below freezing.
527

Adding Washer Fluid
Your vehicle has a low washer uid message in
the DIC that comes on when the washer uid
is low. The message is displayed for 15 seconds
at the start of each ignition cycle. When the
WASHER FLUID LOW ADD FLUID message
displays, you will need to add washer uid to the
windshield washer uid reservoir.
Open the cap with the
washer symbol on it.
Add washer uid
until the tank is full. See
Engine Compartment
Overview on page 500
for reservoir location.Notice:When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not mix water with ready-to-use washer
uid. Water can cause the solution to
freeze and damage your washer uid tank
and other parts of the washer system.
Also, water does not clean as well
as washer uid.
Fill your washer uid tank only
three-quarters full when it is very cold.
This allows for uid expansion if freezing
occurs, which could damage the tank if it is
completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
the vehicle’s winheild washer system and
paint.
528

Brakes
Brake Fluid
The brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 500for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have the
brake system xed, since a leak means that
sooner or later the brakes will not work well.So, it is not a good idea to top off the brake uid.
Adding brake uid will not correct a leak. If
you add uid when the linings are worn, then you
will have too much uid when you get new
brake linings. You should add or remove brake
uid, as necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can
spill on the engine. The uid will burn if
the engine is hot enough. You or others
could be burned, and your vehicle could
be damaged. Add brake uid 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 the brake uid. SeeScheduled
Maintenance (Gasoline Engine) on page 627.
529

Checking Brake Fluid
You can check the brake uid without taking off
the cap.
Just look at the brake
uid reservoir. The uid
level should be above
MIN. If it is not, have the
brake system checked to
see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not
over the MAX mark.
What to Add
When you do need brake uid, use only DOT-3
brake uid. Use new brake uid from a sealed
container only. SeeRecommended Fluids
and Lubricants on page 639.
Always clean the brake uid reservoir cap and the
area around the cap before removing it. This
will help keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
system, the brakes may not work well.
This could cause a crash. Always use the
proper brake uid.
530