brakes GMC YUKON 2003 Owner's Guide

Brakes
Brake Fluid
Your brake master cylinder reservoir isfilled with DOT-3
brakefluid. SeeEngine Compartment Overview on
page 5-12for the location of the reservoir.
There are only two reasons why the brakefluid level in
the reservoir might go down. Thefirst is that the
brakefluid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
thefluid level goes back up. The other reason is
thatfluid is leaking out of the brake system. If it is, you
should have your brake systemfixed, 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 brakefluid.
Adding brakefluid won’t correct a leak. If you addfluid
when your linings are worn, then you’ll have too
muchfluid when you get new brake linings. You should
add (or remove) brakefluid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brakeuid, it can spill on
the engine. Theuid 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 brakefluid. SeePart C: Periodic
Maintenance Inspections on page 6-15.
5-40
2003 - Yukon/Yukon XL

Always clean the brakefluid 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 ofuid 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 brakeuid.
Notice:
Using the wronguid 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 ofuid.
If you spill brakeuid on your vehicle’s painted
surfaces, the paintnish can be damaged. Be
careful not to spill brakeuid 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 pedalfirmly).
{CAUTION:
The brake wear warning sound means 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 arefirst applied or lightly
applied. This does not mean something is wrong with
your brakes.
5-42
2003 - Yukon/Yukon XL

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.
SeeBrake System Inspection on page 6-16.
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 brakingsystem–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.
Battery
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. 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.
5-43
2003 - Yukon/Yukon XL

Tire Chains
{CAUTION:
If your vehicle has P265/75R16, LT265/75R16,
P265/70R16 or P265/70R17 size tires, don’t use
tire chains. They can damage your vehicle
because there’s not enough clearance. Tire
chains used on a vehicle without the proper
amount of clearance can cause damage to the
brakes, suspension or other vehicle parts. The
area damaged by the tire chains could cause
you to lose control of your vehicle and you or
others may be injured in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it’s contacting your vehicle, and don’t
spin your wheels.
If you dond traction devices that willt,
install them on the rear tires.Notice:If you have a tire size other than P265/75R16,
LT265/75R16, P265/70R16 or P265/70R17 use tire
chains only where legal and only when you must. Use
chains that are the proper size for your tires. Install
them on the rear tires only.
Don’t use chains on the front tires.
Tighten them as tightly as possible with the ends
securely fastened. Drive slowly and follow the chain
manufacturer’s instructions. If you can hear the
chains contacting your vehicle, stop and retighten
them. If the contact continues, slow down until
it stops. Driving too fast or spinning the wheels with
chains on will damage your vehicle.
5-68
2003 - Yukon/Yukon XL

*1—Gasoline Engine and Fuel Injection Rail #2.
*2—Gasoline Engine and Fuel Injection Rail #1.
*3—Gasoline Engine; Oxygen Sensors.
*4—Gasoline Engine; Oxygen Sensors.
*5—PCM Ignition
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels
Only)/Dual Battery (TP2) Do
not install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD 2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
Fuses Usage
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Rear Climate Control
5-103
2003 - Yukon/Yukon XL

Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same interval
after 150,000 miles (240 000 km) for the life of this
vehicle.
SeePart B: Owner Checks and Services on page 6-11
andPart C: Periodic Maintenance Inspections on
page 6-15.
Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
+A good time to check your brakes is during tire
rotation. See Brake System Inspection on page 6-16.
Engine Oil and Chassis Lubrication
Scheduled Maintenance
Change engine oil and filter as indicated by the
GM Oil Life System (or every 12 months, whichever
occurs first). Reset the system.
Your vehicle has a computer system that lets you know
when to change the engine oil andfilter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL message will
come on. Change your oil as soon as possible within
the next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, your engine oil andfilter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system.
It is also important to check your oil regularly and keep
it at the proper level.
6-5
2003 - Yukon/Yukon XL

Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. Auid loss could indicate a problem;
check and have it repaired, if needed. On manual
shift transfer case, oil the control lever pivot point. Check
vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chang, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-16
2003 - Yukon/Yukon XL

Reporting Safety Defects to the
Canadian Government
If you live in Canada, and you believe that your vehicle
has a safety defect, you should immediately notify
Transport Canada, in addition to notifying General
Motors of Canada Limited. You may write to:
Transport Canada
330 Sparks Street
Tower C
Ottawa, Ontario K1A 0N5
Reporting Safety Defects to General
Motors
In addition to notifying NHTSA (or Transport Canada) in
a situation like this, we certainly hope you’ll notify us.
Please call us at 1-800-GMC-8782 (1-800-462-8782), or
write:
Pontiac-GMC Customer Assistance Center
P.O. Box 33172
Detroit, MI 48232-5172
In Canada, please call us at 1-800-263-3777 (English)
or 1-800-263-7854 (French). Or, write:
General Motors of Canada Limited
Customer Communication Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Service Publications Ordering
Information
Service Manuals
Service Manuals have the diagnosis and repair
information on engines, transmission, axle, suspension,
brakes, electrical, steering, body, etc.
RETAIL SELL PRICE: $120.00
Transmission, Transaxle, Transfer
Case Unit Repair Manual
This manual provides information on unit repair service
procedures, adjustments, and specications for GM
transmissions, transaxles, and transfer cases.
RETAIL SELL PRICE: $50.00
Service Bulletins
Service Bulletins give technical service information
needed to knowledgeably service General Motors cars
and trucks. Each bulletin contains instructions to
assist in the diagnosis and service of your vehicle.
In Canada, information pertaining to Product Service
Bulletins can be obtained by contacting your General
Motors dealer or by calling 1-800-GM-DRIVE
(1-800-463-7483).
7-10
2003 - Yukon/Yukon XL

Audio System(s) (cont.)
Setting the Time for Radios with Radio Data
Systems (RDS)........................................3-72
Setting the Time for Radios without Radio
Data Systems (RDS)................................3-71
Theft-Deterrent Feature...............................3-122
Understanding Radio Reception...................3-123
XM™Satellite Radio Antenna System...........3-126
Automatic Headlamp System............................3-15
Automatic Level Control...................................4-60
Automatic Transfer Case..................................2-26
Automatic Transmission
Fluid..........................................................5-23
Operation...................................................2-22
Automatic Transmission Check..........................6-12
Automatic Transmission Shift Lock Control
System Check.............................................6-13
Autoride™.....................................................4-60
Auxiliary Roof Mounted Lamp Switch.................3-17
B
Backing Up....................................................4-69
Battery..........................................................5-43
BATTERY NOT CHARGING.............................3-65
Battery Replacement......................................... 2-6
Battery Run-Down Protection............................3-20
Battery Warning Light......................................3-42
Before Leaving on a Long Trip.........................4-44
Before You Drive...........................................3-111Before You Go Off-Roading..............................4-25
Bench Seat....................................................1-15
Bench Seat Split (50/50)..................................1-11
Bench Seat, Split (60/40)................................... 1-9
Body Lubrication Service..................................6-12
Brake
Parking......................................................2-34
System Inspection.......................................6-16
System Warning Light..................................3-43
Brake Adjustment............................................5-43
Brake Fluid
....................................................5-40
Brake Pedal, Throttle
.......................................2-21
Brake Pedal Travel
.........................................5-43
Brake Wear
...................................................5-42
Brakes
..........................................................5-40
Braking
........................................................... 4-6
Braking in Emergencies
..................................... 4-9
Break-In, New Vehicle
.....................................2-18
Bucket Seats, Rear
.........................................1-20
Bulb Replacement
...........................................5-52
Front Turn Signal, Sidemarker and Daytime
Running Lamps
........................................5-54
Halogen Bulbs
............................................5-53
Headlamps
.................................................5-53
Replacement Bulbs
......................................5-59
Roof Marker Lamps
.....................................5-55
Side Identification Marker Lamps
...................5-55
Taillamps
....................................................5-57
Buying New Tires
...........................................5-64
2
2003 - Yukon/Yukon XL

Theft-Deterrent Systems (cont.)
Content Theft-Deterrent................................2-16
Passlock
®...................................................2-18
Third Row......................................................1-64
Throttle, Adjustable..........................................2-21
Tilt Wheel........................................................ 3-7
Tilting the 50/50 Split Bench Seat.....................1-12
Tilting the Bench Seat.....................................1-16
Tire Inflation Check.........................................6-11
Tires.............................................................5-60
Buying New Tires........................................5-64
Chains.......................................................5-68
Changing a Flat Tire....................................5-69
If a Tire Goes Flat.......................................5-69
Inflation -- Tire Pressure...............................5-61
Inspection and Rotation................................5-61
Spare Tire..................................................5-88
Uniform Tire Quality Grading.........................5-65
Wheel Alignment and Tire Balance.................5-66
Wheel Replacement.....................................5-66
When It Is Time for New Tires......................5-63
To Use the Engine Coolant Heater....................2-22
Top Strap......................................................1-54
Top Strap Anchor Location...............................1-55
Torque Lock...................................................2-37
Total Weight on Your Vehicle’s Tires..................4-66
Tow/Haul Mode ...............................................2-25Tow/Haul Mode Light.......................................3-52
Towing
Recreational Vehicle.....................................4-55
Towing a Trailer..........................................4-61
Your Vehicle...............................................4-54
Traction
Assist System (TAS)....................................4-10
Off Light.....................................................3-45
Stabilitrak
®System......................................4-12
TRACTION ACTIVE........................................3-68
Traction Control Operation................................4-13
Trailer
Recommendations
.......................................4-60
Trailer Brakes
.................................................4-68
Trailer Wiring Harness
.....................................4-72
Transfer Case
........................................5-49, 5-51
Transfer Case and Front Axle (Four-Wheel Drive)
Inspection
...................................................6-16
Transmission
Fluid, Automatic
...........................................5-23
Temperature Gage
.......................................3-46
TRANSMISSION HOT
.....................................3-68
Transmission Operation, Automatic
....................2-22
Transmission, Transaxle, Transfer Case Unit
Repair Manual
............................................7-10
Transportation Options
...................................... 7-8
16
2003 - Yukon/Yukon XL