2004 GMC YUKON air suspension

After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule
for additional information.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired — by alcohol or drugs, with night vision
problems, or by fatigue.
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The Certication/Tire label also tells you the maximum
weights for the front and rear axles, called Gross
Axle Weight Rating (GAWR). To nd out the actual loads
on your front and rear axles, you need to go to a
weigh station and weigh your vehicle. Your dealer can
help you with this. Be sure to spread out your load
equally on both sides of the centerline.
Never exceed the GVWR for your vehicle, or the GAWR
for either the front or rear axle.
The Certication/Tire label also contains information
about your Front Axle Reserve Capacity. See “Front
Axle Reserve Capacity” later in this section.
And, if you do have a heavy load, you should spread
it out.
{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
The label will help you decide how much cargo and
installed equipment your truck can carry.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask your
dealer to help you load your vehicle the right way.
If you put things inside your vehicle – like suitcases,
tools, packages, or anything else – they go as fast
as the vehicle goes. If you have to stop or turn quickly,
or if there is a crash, they’ll keep going.
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{CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or
in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight evenly.
Never stack heavier things, like suitcases,
inside the vehicle so that some of them
are above the tops of the seats.
Do not leave an unsecured child restraint
in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down unless
you need to.
There’s also important loading information for off-road
driving in this manual. See″Loading Your Vehicle
for Off-Road Driving″in the Index.
Level Control
Automatic Level Control
The automatic level control rear suspension is available
on C/K 1500 vehicles and comes as a part of the
Autoride™ suspension, if equipped.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected to the rear
shocks will raise or lower the rear of the vehicle
to maintain proper vehicle height. The system is
activated when the ignition key is turned to RUN and
will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up to
ten minutes after the ignition key has been turned off.
You may hear the air compressor operating when
the height is being adjusted.
If a self-equalizing hitch is being used, it is
recommended to allow the shocks to inate, thereby
leveling the vehicle prior to adjusting the hitch.
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Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. Reset oil life system. SeeEngine Oil on
page 5-16.An Emission Control Service.••
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner lter or change indicator (if equipped). If necessary,
replace lter. SeeEngine Air Cleaner/Filter on page 5-21.An Emission Control
Service. See footnote †.••
Rotate tires and check ination pressures and wear. SeeTires on page 5-63.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid as
needed.••
Perform any needed additional services. See “Additional Required Services” in
this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission uid level and add uid as needed.•
6-5

Additional Required Services (cont’d)
Service25,000
(41 500)50,000
(83 000)75,000
(125 000)100,000
(166 000)125,000
(207 500)150,000
(240 000)
Replace spark plugs and inspect
spark plug wires.An Emission
Control Service.•
Engine cooling system service (or
every 5 years, whichever occurs
rst).An Emission Control Service.
See footnote (i).•
Inspect engine accessory drive belt.
An Emission Control Service.•
Maintenance 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.
#Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage and parking
brake cable guides. Ball joints should not be lubricated
unless their temperature is 10°F (-12°C) or higher,
or they could be damaged.(a)Visually 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.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing parts,
signs of wear or lack of lubrication. Inspect power
steering lines and hoses for proper hook-up, binding,
leaks, cracks, chang, etc. Visually check constant
velocity joints, rubber boots and axle seals for leaks.
6-7

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
7-12