2004 GMC YUKON Owner's Manual

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.6. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated.
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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.
Power Steering Fluid
8100 Engines
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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. SeeEngine Compartment Overview
on page 5-12for 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 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 6-12.
Always use the proper uid. Failure to use the proper
uid can cause leaks and damage hoses and seals. All Other Engines
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Windshield Washer Fluid
What to Use
When you need windshield washer uid, 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 uid that has sufficient
protection against freezing. SeeEngine Compartment
Overview on page 5-12for reservoir location.
Adding Washer Fluid
Your vehicle has a low washer uid message 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 CHECK WASHER FLUID message is
displayed, you will need to add washer uid to the
windshield washer uid reservoir.
The windshield washer
uid reservoir is located in
the engine compartment
toward the front of the
vehicle on the driver’s side.
Open the cap with the washer symbol on it. Add washer
uid until the tank is full.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 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 your washer
system and paint.
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Brakes
Brake Fluid
Your brake master cylinder reservoir is lled with DOT-3
brake uid. SeeEngine Compartment Overview on
page 5-12for 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 your brake system xed, since a leak
means that sooner or later your brakes will not work
well, or will not work at all.
So, it is not a good idea to “top off” your brake uid.
Adding brake uid will not correct a leak. If you add uid
when your 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 your brake uid. SeeScheduled Maintenance
on page 6-4.
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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 your 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 6-12.
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 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 uid.
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Notice:
Using the wrong uid 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 will have to be replaced. Do not
let someone put in the wrong kind of uid.
If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged. Be
careful not to spill brake uid on your vehicle. If
you do, wash it off immediately. SeeAppearance
Care on page 5-103.
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 rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes will not work well. That
could lead to an accident. When you hear the
brake wear warning sound, have your vehicle
serviced.
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 rst 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 specications.
Brake linings should always be replaced as complete
axle sets.
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Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. Your
vehicle was designed and tested with top-quality GM
brake parts. When you replace parts of your braking
system — for example, when your brake linings
wear down and you need new ones put in — be sure
you get new approved GM replacement parts. If you do
not, your brakes may no longer work properly. For
example, if someone puts in brake linings that are wrong
for your vehicle, the balance between your front and
rear brakes can change — for the worse. The braking
performance you have come to expect can change
in many other ways if someone puts in the wrong
replacement brake parts.
Battery
Your new vehicle comes with a maintenance free
ACDelco®battery. When it is time for a new battery, get
one that has the replacement number shown on the
original battery’s label. We recommend an ACDelco
®
battery. SeeEngine Compartment Overview on
page 5-12for battery location.
Warning:Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.
Vehicle Storage
If you are not going to drive your vehicle for 25 days
or more, remove the black, negative (−) cable from
the battery. This will help keep your battery from
running down.
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