engine GMC YUKON DENALI 2003 Owners Manual

Brakes
Brake Fluid
Your brake master cylinder reservoir is filled with DOT-3
brake fluid. See Engine Compartment 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 you have too n._.:h brake ------) it can s,
the engine. The fluid will burn if the enginc
... I on
e 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.
5-36

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

Brake Pedal Travel Battery
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 don’t, 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’ve come to expect can change
in many other ways
if someone puts in the wrong
replacement brake parts. Your
new vehicle comes with a maintenance free
ACDelco@ battery. When it’s time for a new battery, get
one that has the replacement number shown on the
original battery’s label. We recommend an ACDelco@
battery. See Engine Compartment Overview
on
page 5-72 for 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’re not going to drive your vehicle for 25 days or
more, remove the black, negative
(-) cable from
+‘-? battery. This will hc’- keep your battery from
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren’t careful. See “Jump Starting” next for
tips on working around a battery without
getting hurt.
5-39

Notice: If the other system isn’t a 12-volt system
with a negative ground, both vehicles can be
damaged.
2.
Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other.
If they are, it could cause a ground
connection you don’t want. You wouldn’t be able
to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
Notice: If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn
off the
radio and all lamps that aren’t needed. This
will avoid sparks and help save both batteries.
And it could save your radio!
4. Open the hoods and locate the positive (+) and
negative
(-) terminal locations of the other vehicle.
Your vehicle has a remote positive
(+) jump
starting terminal and a remote negative
(-) jump
starting terminal.
You should always use these
remote terminals instead
of the terminals on the
battery.
The remote positive
(+)
terminal is located under a red plastic cover near
the engine accessory drive
bracket.
To access the
remote positive
(+)
terminal, open the red
plastic cover.
5-41

The remote negative (-)
terminal is located on
the engine accessory
drive bracket and
is
marked GND.
See Engine Compartment Overview on page 5-12
for more information on location. 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
flashlight
if you need more light.
Be sure the battery has enough water. You
don’t need to add water to the ACDelco@
battery installed in your new vehicle. But
if a
battery has filler caps, be sure the right
amount of fluid is there.
If it is low, add water
to take care of that first. If you don’t, explosive
gas could be present.
Battery fluid contains acid that can burn you.
Don’t get
it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
J
5-42

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 to a remote positive terminal (+) if
the vehicle has one. Negative (-) will go to a heavy,
unpainted metal engine part or
to 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.
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
6. Connect the red
positive
(+) cable to the
positive
(+) terminal of the
dead battery. Use a
remote positive
(+)
terminal if the vehicle
has one.
7. Don’t let the other end
touch metal. Connect it
to the positive
(+)
terminal of the good
battery. Use a remote positive
(+) terminal
if the vehicle has one
5-43

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

A a
Jumper Cable Removal
A. Heavy, Unpainted Metal Engine Part or Remote
B. Good Battery or Remote Positive
(+) and
C. Dead Battery or Remote Positive (+) Terminal.
Negative
(-) Terminal.
Negative
(-) Terminals.
To disconnect the jumper cables from both vehicles do
the following:
1. Disconnect the black negative (-) cable from the
vehicle that had the dead battery.
2. Disconnect the black negative (-) cable from the
3. Disconnect the red positive (+) cable from the
4. Disconnect the red positive (+) cable from the other
5. Return the positive (+) remote terminal cover to its
vehicle
with the good battery.
vehicle with the good battery.
vehicle. original position.
5-45

If a Tire Goes Flat
It’s unusual for a tire to “blowout” while you’re driving,
especially
if you maintain your tires properly. If air goes
out
of a tire, it’s much more likely to ieak out siowiy.
But if you should ever have a “blowout”, here are a few
tips about what
to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot
off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake
to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use
in a skid.
In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle
to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warning
fi hers.
Changing a tire can cause an injury. The
vehicle can slip
off the jack and roll over you
or other people. You and they could be badly injured. Find a level place to change your tire.
To help prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine.
4. Put the wheel blocks at the front and rear
of the tire farthest away from the one
being changed. That would be the tire on
the other side
of the vehicle, at the
opposite end.
5-63

Vehicle Identification
Vehicle Identification Number (VIN)
SAMPLE4UXl M072675
This is the legal identifier for your vehicle. It appears on
a plate in the front corner of the instrument panel, on
the driver’s side. You can see it
if you look through the
windshield from outside your vehicle. The VIN also
appears on the Vehicle Certification and Service Parts
labels and the certificates of title and registration.
Engine Identification
The 8th character in your VIN is the engine code. This
code will help you identify your engine, specifications
and replacement parts.
Service Parts Identification Label
You’ll find this label located in the glove box. It’s very
helpful
if you ever need to order parts. On this label is:
your VIN,
the model designation’
paint information and
a list of all production options and special
equipment.
Be sure that this label is not removed from the vehicle.
5-86