2003 GMC YUKON DENALI service

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 wea rarl -g sou.-_. ... eans that
soon your brakes won’t 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 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 6-14.
5-38

8. Now connect the black
negative
(-) cable to the
negative
(-) terminal
of the good battery. Use
a remote negative
(-)
terminal if the vehicle has
one. Your vehicle’s
remote negative
(-)
terminal is marked GND.
Don’t let the other end touch anything until the next
step. The other end of the negative
(-) cable
doesn’t go to the dead battery.
It goes to a heavy,
unpainted metal engine part or
to a remote
negative
(-) terminal on the vehicle with the
dead battery.
9. Connect the other end of
the negative (-) cable at
least
18 inches (45 cm)
away from the dead
battery, but not near
engine parts that move.
The electrical connection is just as good there, and
the chance of sparks getting back
to the battery
is much less.
10. Now start the vehicle with the good battery and run
the engine for awhile.
11. Try to start the vehicle that had the dead battery. If
it won’t start after a few tries, it probably needs
service.
Notice: Damage to your vehicle may result from
electrical shorting if jumper cables are removed
incorrectly.
To prevent electrical shorting, take care
that the cables don’t touch each other or any
other metal. The repairs wouldn’t be covered by
your warranty.
5-44

Front Axle To get an accurate reading, the vehicle should be on a
When to Check and Change Lubricant level surface.
If the level
is below the bottom of the filler plug hole,
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See you may need to add
some lubricant.
Part
A: Scheduled Maintenance Services on page 6-4. When the differential is cold, add enough lubricant to
raise the level to 1/2 inch (12 mm) below the filler
How to Check Lubricant plug hole.
When the differential is at operating temperature
(warm), add enough lubricant
to raise the level to the
bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant
to use. See Part D: Recommended
Fluids and Lubricants on page
6-15.
5-47

Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See Part
A: Scheduled
Maintenance Services
on page 6-4.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
The proper level is from
5/8 inch to 1 5/8 inch (15 mm to
40 mm) below the bottom of the filler plug hole. Add
only enough fluid to reach the proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind
of lubricant to use. See Part D: Recommended
Fluids and Lubricants
on page 6-15.
5-48

Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your Warranty booklet for details.
Poorly
m-. ltained anc nproperly used 1 !s
are dangerous.
Overloading your tires can cause
overheating as
a result of too much
friction. You could have an air-out and a
serious accident. See “Loading Your
Vehicle”
in the Index.
0 Underinflated tires pose the same danger
as overloaded tires. The resulting accident could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
CAUTION: (Continued)
Overinflated tires are more likely to be
cut, punctured or broken by a sudden
impact
- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If
your tread is badly worn, or if your tires
have been damaged, replace them.
Inflation -- Tire Pressure
The CertificationKire label, which is on the rear edge of
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold. “Cold” means your
vehicle has been sitting for at least three hours
or driven
no more than
1 mile (1.6 km).
5-55

Notice: Don’t let anyone tell you that underinflation
or overinflation is all right. It’s not. If your tires
don’t have enough air (underinflation), you can get
the following:
Too much flexing
Too much heat
0 Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overinflation), you
can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell
if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Inspection and Rotation
Tires should be rotated every 7,500 miles (12,500 km).
Any time you notice unusual wear, rotate your tires
as soon as possible and check wheel alignment.
Also
check for damaged tires or wheels. See When It Is Time
for New Tires on page
5-58 and Wheel Replacement
on page
5-61 for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If
it moves,
use the wheel wrench and jack handle extensions
to
tighten the cable. See Changing a Flat Tire on
page 5-63.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle.
The first rotation
is the most important. See “Part
A: Scheduled
Maintenance Services,” in Section
6, for scheduled
rotation intervals.
5-56

When It Is Time for New Tires
One way to tell when it’s
time for new tires is
to
check the treadwear
indicators, which will
appear when your tires have only
1/16 inch
(1.6 mm) or less of tread
remaining. Some
commercial truck tires may
not have treadwear indicators.
You need a new tire
if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
. The tread or sidewall is cracked, cut or snagged
The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
tire’s rubber.
deep
enough
to show cord or fabric.
can’t be repaired well because of the size or
location
of the damage.
Buying New Tires
To find out what kind and size of tires you need, look at
the CertificationlTire label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specifications (TPC
Spec) number on each tire’s sidewall. When you get
new tires, get ones with that same TPC Spec number.
That way your vehicle will continue
to have tires
that are designed to give proper endurance, handling,
speed rating, traction, ride and other things during
normal service on your vehicle. If your tires have an
all-season tread design, the TPC number will be
followed by an
“MS” (for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.
5-58

While the tires available on General Motors passenger
cars and light trucks may vary with respect
to these
grades, they must also conform
to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course.
For example, a tire graded
150 would wear one and
a half
(1.5) times as well on the government course as
a tire graded
100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart significantly from the norm
due
to variations in driving habits, service practices and
differences
in road characteristics and climate.
Traction - AA, A, 6, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of
asphalt and concrete.
A tire marked C may have poor
traction performance. Warning: The traction grade assigned
to this tire is based
on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
Temperature - A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire’s resistance
to the generation
of heat and its ability
to dissipate heat when tested
under controlled conditions on a specified indoor
laboratory test wheel. Sustained high temperature can
cause the material
of the tire to degenerate and
reduce tire life, and excessive temperature can lead
to
sudden tire failure. The grade C corresponds to a
level of performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the
minimum required
by law.
Warning: The temperature grade for this tire is
established for a tire that is properly inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
5-60