2004 GMC YUKON fuel cap release

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuel E-85 (85% Ethanol).................................5-6
Fuels in Foreign Countries...............................5-8
Filling Your Tank............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-23
Engine Coolant.............................................5-26
Coolant Surge Tank Pressure Cap..................5-28
Engine Overheating.......................................5-29Cooling System............................................5-32
Engine Fan Noise.........................................5-38
Power Steering Fluid.....................................5-38
Windshield Washer Fluid................................5-40
Brakes........................................................5-41
Battery........................................................5-44
Jump Starting...............................................5-45
All-Wheel Drive..............................................5-51
Rear Axle.......................................................5-52
Four-Wheel Drive............................................5-53
Front Axle......................................................5-54
Bulb Replacement..........................................5-55
Halogen Bulbs..............................................5-55
Headlamps..................................................5-55
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-56
Side Identication Marker Lamps.....................5-57
Roof Marker Lamps......................................5-58
Taillamps.....................................................5-60
Replacement Bulbs.......................................5-61
Section 5 Service and Appearance Care
5-1

Ination - Tire Pressure
The tire and loading information label, shows the correct
ination 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). See
Loading Your Vehicle on page 4-56, for the location
of your vehicle’s tire and loading information label.
Notice:Don’t let anyone tell you that underination
or overination is all right. It’s not. If your tires
don’t have enough air (underination), you can get
the following:
Too much exing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overination), 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 inated
simply by looking at them. Radial tires may look
properly inated even when they’re underinated. Check
the tire’s ination pressure when the tires are cold.
cold means your vehicle has been sitting for at least
three hours or driven no more than 1 mile (1.6 km).
remove the valve cap from the tire valve stem. Press the
tire gage rmly onto the valve to get a pressure
measurement. If the cold tire ination pressure matches
the recommended pressure on the tire and loading
information label, no further adjustment is necessary. If
the pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on the
metal stem in the center of the tire valve. Recheck the
tire pressure with the tire gage.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
5-72

(c)Visually inspect hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace with genuine GM parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or cracking.
Replace blade inserts that appear worn or damaged
or that streak or miss areas of the windshield.
(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken air bag
coverings, and have them repaired or replaced. (The air
bag system does not need regular maintenance.)
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl, rear
compartment hinges, outer liftgate handle pivot points,
rear door detent link, roller mechanism, liftgate handle
pivot points, latch bolt, fuel door hinge, cargo door hinge,
locks and folding seat hardware. More frequent
lubrication may be required when exposed to a corrosive
environment. Applying silicone grease on weatherstrips
with a clean cloth will make them last longer, seal better
and not stick or squeak.(g)Add uid as needed. A uid loss could indicate a
problem; repair as needed. Check vent hose at transfer
case for kinks and proper installation.
(h)Change automatic transmission uid and lter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-26for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ller neck.
Pressure test the cooling system and pressure cap.
(j)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the uid level checked. Add uid if needed.
(k)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing and condition.
Check that the purge valve works properly (if equipped).
Replace as needed.
6-8