DIC GMC YUKON 2004 Owner's Manual

Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not 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 do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
Checking Coolant
The coolant surge tank is
located in the engine
compartment on the
passenger’s side of the
vehicle. SeeEngine
Compartment Overview on
page 5-12for more
information on location.
{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
FULL COLD mark.
If your vehicle is equipped with a low coolant sensor,
and the LOW COOLANT LEVEL message comes
on and stays on, it means you’re low on engine coolant.
See “Low Coolant Level” underDIC Warnings and
Messages on page 3-70.
5-27

Engine Overheating
You will nd a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-49. In addition, you will
nd an ENGINE OVERHEATED, and a REDUCED
ENGINE POWER message in the DIC on the instrument
panel. SeeDriver Information Center (DIC) on
page 3-58.
Overheated Engine Protection
Operating Mode (V8 Engines Only)
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance.This operating mode allows your vehicle to be driven to
a safe place in an emergency. Driving extended
miles (km) and/or towing a trailer in the overheat
protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. SeeEngine Oil on page 5-16.
5-29

Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty. See “Overheated
Engine Protection Operating Mode” underEngine
Overheating on page 5-29for information on driving
to a safe place in an emergency.
If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant condition,
can indicate a serious problem. SeeLow Coolant
underDIC Warnings and Messages on page 3-70.
If you get an engine overheat warning with and do not
have a low coolant condition, but see or hear no steam,
the problem may not be too serious. Sometimes the
engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on page 4-63.If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in neutral while
stopped. If it is safe to do so, pull off the road. Shift
to park or neutral and let the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, you can push down the
accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off
the engine and get everyone out of the vehicleuntil it
cools down. Also, seeOverheated Engine Protection
Operating Modelisted previously in this section.
You may decide not to lift the hood but to get service
help right away.
5-31

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
5-39

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.
5-43

{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
ashlight if you need more light.
Be sure the battery has enough water. You do
not need to add water to the ACDelco
®battery
installed in your new vehicle. But if a battery
has ller caps, be sure the right amount of
uid is there. If it is low, add water to take care
of that rst. If you do not, explosive gas could
be present.
Battery uid contains acid that can burn you.
Do not get it on you. If you accidentally get it
in your eyes or on your skin, ush the place
with water and get medical help immediately.
{CAUTION:
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
5. Check that the jumper cables don’t have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or a remote positive (+) terminal if the
vehicle has one. Negative (−) will go to a heavy,
unpainted metal engine part or a remote
negative (−) terminal if the vehicle has one.
Don’t connect positive (+) to negative (−) or you’ll
get a short that would damage the battery and
maybe other parts too. And don’t connect the
negative (−) cable to the negative (−) terminal on
the dead battery because this can cause sparks.
5-47

Rear Axle
When to Check Lubricant
It is not necessary to regularly check rear axle uid
unless you suspect there is a leak or you hear an
unusual noise. A uid loss could indicate a problem.
Have it inspected and repaired.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
The proper level for the 1500 Series is from 5/8 inch to
1 5/8 inch (15 mm to 40 mm) below the bottom of the ller
plug hole. The proper level for the 2500 Series is from
0 to 1/2 inch (0 to 13 mm) below the bottom of the ller
plug hole. The proper level for the 1500 and 2500 series
vehicles with QUADRASTEER™ (4 Wheel Steer) is from
0 to 1/4 inch (0 to 6 mm) below the ller plug hole. Add
only enough uid to reach the proper level.
What to Use
To determine what kind of lubricant to use, see
Recommended Fluids and Lubricants on page 6-12.
1500 Series shown, 2500 similar
5-52

Four-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
It is not necessary to regularly check transfer case uid
unless you suspect there is a leak, or you hear an
unusual noice. A uid loss could indicate a problem.
Have it inspeced and repaired.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the ller plug hole,
you’ll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the ller plug hole.
Use care not to overtighten the plug.
When to Change Lubricant
Refer to the Maintenance Schedule to determine how
often to change the lubricant. SeeScheduled
Maintenance on page 6-4.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeeRecommended Fluids
and Lubricants on page 6-12.
Automatic Transfer Case
5-53

Front Axle
When to Check Lubricant
It is not necessary to regularly check front axle uid
unless you suspect there is a leak or you hear an
unusual noise. A uid loss could indicate a problem.
Have it inspected and repaired.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the ller plug hole,
you may need to add some lubricant.
When the differential is cold, add enough lubricant to
raise the level to 0 to 3/8 inch (9.5 mm) below the ller
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of the ller plug hole.
What to Use
To determine what kind of lubricant to use, see
Recommended Fluids and Lubricants on page 6-12.
5-54

(A) Tire Size Code:The tire size code is a combination
of letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction type and
service description. See the “Tire Size Code” illustration
later in this section for more detail.
(B) Tire Performance Criteria Specication (TPC
Spec):Original equipment tires designed to GM’s
specic tire performance criteria have a TPC specication
code molded onto the sidewall. GM’s TPC specications
meet or exceed all federal safety guidelines.
(C) Department of Transportation (DOT):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(D) Tire Identication Number (TIN):The letters and
numbers following DOT code are the Tire Identication
Number (TIN). The TIN shows the manufacturer
and plant code, tire size, and date the tire was
manufactured. The TIN is molded onto both sides of the
tire, although only one side may have the date of
manufacture.
P-Metric Tire
5-64