2008 GMC YUKON DENALI checking oil

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-3
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling the Tank..............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Oil Life System..................................5-16
Engine Air Cleaner/Filter................................5-17
Automatic Transmission Fluid.........................5-20
Engine Coolant.............................................5-23
Coolant Surge Tank Pressure Cap..................5-26
Engine Overheating.......................................5-26
Overheated Engine Protection
Operating Mode........................................5-28Cooling System............................................5-29
Engine Fan Noise.........................................5-34
Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
All-Wheel Drive..............................................5-45
Rear Axle.......................................................5-46
Front Axle......................................................5-47
Headlamp Aiming...........................................5-48
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-51
License Plate Lamp......................................5-52
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-53
Tires..............................................................5-55
Tire Sidewall Labeling...................................5-56
Tire Terminology and Denitions.....................5-58
Ination - Tire Pressure.................................5-60
High-Speed Operation...................................5-62
Tire Pressure Monitor System.........................5-62
Tire Pressure Monitor Operation.....................5-64
Section 5 Service and Appearance Care
5-1

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools away
from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer and
other uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
Hood Release
To open the hood do the following:
1. Pull the handle with
this symbol on it. It is
located inside the
vehicle to the lower left
of the steering wheel.
5-10

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-17.
B. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 5-17.
C. Coolant Surge Tank and Pressure Cap. SeeCooling
System on page 5-29andCoolant Surge Tank
Pressure Cap on page 5-26.
D. Remote Positive (+) Terminal. SeeJump Starting
on page 5-40.
E. Battery. SeeBattery on page 5-39.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-13.
G. Automatic Transmission Dipstick (Out of View).
See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-20.
H. Remote Negative (−) Terminal (GND) (Out of View).
SeeJump Starting on page 5-40.
I. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-13.
J. Engine Cooling Fan (Out of View). SeeCooling
System on page 5-29.
K. Power Steering Fluid Reservoir (Out of View).
SeePower Steering Fluid on page 5-34.L. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-36.
M. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-111.
N. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-35.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-13

Checking Brake Fluid
The brake uid can be checked without taking off the
cap by looking at the brake uid reservoir.
The uid level should be
above MIN. If it is not,
have the brake hydraulic
system checked to see if
there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over
the MAX mark.
What to Add
When you do need brake uid, use only DOT-3 brake
uid. Use new brake uid from a sealed container
only. SeeRecommended Fluids and Lubricants
on page 6-12.Always clean the brake uid reservoir cap and the area
around the cap before removing it. This helps keep dirt
from entering the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
hydraulic system, the brakes might not work
well. This could cause a crash. Always use the
proper brake uid.
Notice:
Using the wrong uid can badly damage brake
hydraulic system parts. For example, just a few
drops of mineral-based oil, such as engine oil, in
the brake hydraulic system can damage brake
hydraulic system parts so badly that they will
have to be replaced. Do not let someone put in
the wrong kind of uid.
If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged.
Be careful not to spill brake uid on your vehicle.
If you do, wash it off immediately. SeeWashing
Your Vehicle on page 5-102.
5-37

(c)Visually inspect hoses and have them replaced if
they are cracked, swollen, or deteriorated. Inspect all
pipes, fittings, and clamps; replace with genuine 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)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. See Windshield Wiper Blade Replacement on
page 5-53 and Windshield, Backglass, and Wiper
Blades on page 5-103for more information.
(e)Make sure the safety belt reminder light and safety
belt assemblies 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 see Checking the Restraint
Systems on page 1-92.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
door hinges, liftgate hinge, liftgate linkage, liftgate handle
pivot points, latch bolt, fuel 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)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.
(h)Change automatic transmission fluid and filter 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, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-23
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(l)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
(m)Check vent hose at transfer case for kinks and
proper installation.
6-8

G
Gage
Engine Coolant Temperature.........................3-41
Fuel..........................................................3-48
Oil Pressure...............................................3-45
Speedometer..............................................3-33
Tachometer.................................................3-33
Voltmeter Gage...........................................3-38
Garage Door Opener.......................................2-50
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Glove Box.....................................................2-58
GM Mobility Reimbursement Program.................. 7-6
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-8
Headlamp
Aiming.......................................................5-48
Headlamps
Bulb Replacement.......................................5-50
Daytime Running Lamps...............................3-17
Exterior Lamps............................................3-16
Flash-to-Pass............................................... 3-9Headlamps (cont.)
Halogen Bulbs............................................5-50
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-17
Heated Seats................................................... 1-4
Heated Steering Wheel..................................... 3-7
Heater...........................................................3-23
Highbeam On Light.........................................3-47
High-Speed Operation, Tires.............................5-62
Highway Hypnosis...........................................4-27
Hill and Mountain Roads..................................4-28
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn............................................................... 3-6
How to Wear Safety Belts Properly...................1-33I
Ignition Positions.............................................2-26
Infants and Young Children, Restraints...............1-52
Ination - Tire Pressure...................................5-60
Instrument Panel
Overview..................................................... 3-4
Storage Area..............................................2-59
6