2007 GMC YUKON XL light

Engine Air Cleaner/Filter
SeeEngine
Compartment Overview
on page 436for the
location of the engine air
cleaner/lter and the
air lter restriction
indicator, if the vehicle
has one.
When to Inspect the Engine Air
Cleaner/Filter
If your vehicle has an air lter restriction indicator,
it lets you know when the engine air cleaner/lter
needs to be replaced. On vehicles with a restriction
indicator, you should inspect the air lter
restriction indicator at every oil change and
replace the engine air cleaner/lter when the
indicator tells you to.
On vehicles without an air lter restriction indicator,
inspect the air cleaner/lter at the MaintenanceII
intervals and replace it at the rst oil change
after each 50,000 mile (83 000 km) interval.SeeScheduled Maintenance on page 555for
more information. If you are driving in dusty/dirty
conditions, inspect the lter at each engine oil
change.
How to Inspect the Engine Air
Cleaner/Filter
Vehicles With an Air Filter Restriction
Indicator
Locate the air lter restriction indicator on the
engine air cleaner/lter cover. When the indicator
turns black or is in the red/orange “change”
zone, replace the lter and reset the indicator.
See the steps following to replace the engine air
cleaner/lter and to reset the air lter restriction
indicator.
Vehicles Without an Air Filter Restriction
Indicator
To inspect the air cleaner/lter, remove the engine
air cleaner/lter from the vehicle using the steps
following. When you have the engine air
cleaner/lter removed, lightly shake it to release
loose dust and dirt. If the engine air cleaner/lter
remains caked with dirt, a new lter is required.
443

Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is
designed to remain in your vehicle for ve years or
150,000 miles (240 000 km), whichever occurs
rst, if you add only DEX-COOL
®extended
life coolant.
The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 452.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to
−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant may require changing sooner, at
the rst maintenance service after each
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
449

Brakes
Brake Fluid
Your brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 436for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have your
brake system xed, since a leak means that
sooner or later your brakes will not work well, or
will not work at all.So, it is not a good idea to top off your brake uid.
Adding brake uid will not correct a leak. If you
add uid when your linings are worn, then you will
have too much uid when you get new brake
linings. You should add or remove brake uid, as
necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can
spill on the engine. The uid 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.
When the brake uid falls to a low level, the brake
warning light will come on. SeeBrake System
Warning Light on page 232.
Refer to the Maintenance Schedule to determine
when to check your brake uid. SeeScheduled
Maintenance on page 555.
463

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 rmly.
{CAUTION:
The brake wear warning sound means that
soon your brakes will not 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 rst 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
specications.
Brake linings should always be replaced as
complete axle sets.
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.
465

Notice:If you leave your radio or other
accessories on during the jump starting
procedure, they could be damaged. The repairs
would not be covered by your warranty. Always
turn off your radio and other accessories when
jump starting your vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the
cigarette lighter or the accessory power
outlets. Turn off the radio and all the lamps
that are not needed. This will avoid sparks and
help save both batteries. And it could save
the radio!
4. Open the hood on the other vehicle and
locate the positive (+) and negative (−)
terminal locations on that 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, if equipped, is
located under a red plastic cover at the positive
battery post. To uncover the remote positive (+)
terminal, open the red plastic cover.
The remote negative (-) terminal is a stud
located on the right front of the engine, where
the negative battery cable attaches.
SeeEngine Compartment Overview on
page 436for more information on the location
of the remote positive (+) and remote
negative (−) terminals.
{CAUTION:
An electric fan can start up even when the
engine is not running and can injure you.
Keep hands, clothing and tools away from
any underhood electric fan.
468

{CAUTION:
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 ashlight if you need more
light.
Be sure the battery has enough water.
You do not need to add water to the
battery installed in your new vehicle.
But if a battery has ller caps, be sure the
right amount of uid is there. If it is low,
add water to take care of that rst. If you
do not, explosive gas could be present.
Battery uid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on your
skin, ush the place with water and get
medical help immediately.
{CAUTION:
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
5. Check that the jumper cables do not 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.
Do not connect positive (+) to negative (−)or
you will get a short that would damage
the battery and maybe other parts too. And do
not connect the negative (−) cable to the
negative (−) terminal on the dead battery
because this can cause sparks.
469

What to Use
Refer to the Maintenance Schedule to determine
what kind of lubricant to use. SeeRecommended
Fluids and Lubricants on page 564.
Headlamp Aiming
The vehicle has a visual optical headlamp aiming
system. The aim of the headlamps have been
preset at the factory and should need no further
adjustment.
However, if the vehicle is damaged in an accident,
the aim of the headlamps may be affected and
adjustment may be necessary.
If oncoming vehicles ash their high beams at
you, this may mean the vertical aim of your
headlamps needs to be adjusted.
It is recommended that the vehicle is taken to your
dealer for service if the headlamps need to be
adjusted. It is possible however, to re-aim
the headlamps as described in the following
procedure.The vehicle should be properly prepared as
follows:
The vehicle should be placed so the
headlamps are 25 ft. (7.6 m) from a light
colored wall.
The vehicle must have all four tires on a level
surface which is level all the way to the wall.
The vehicle should be placed so it is
perpendicular to the wall.
The vehicle should not have any snow, ice, or
mud on it.
The vehicle should be fully assembled and all
other work stopped while headlamp aiming is
being performed.
The vehicle should be normally loaded with
a full tank of fuel and one person or
160 lbs (75 kg) sitting on the driver’s seat.
Tires should be properly inated.
The spare tire is in its proper location in the
vehicle.
Headlamp aiming is done with the vehicle’s
low-beam headlamps. The high-beam headlamps
will be correctly aimed if the low-beam headlamps
are aimed properly.
475

To adjust the vertical aim, do the following:
1. Open the hood. SeeHood Release on
page 435for more information.
2. Locate the aim dot on the lens of the
low-beam headlamp.
3. Measure the distance from the ground to the
aim dot on the low-beam headlamp. Record
the distance.4. At the wall or other at surface, measure from
the ground upward (A) to the recorded
distance from Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall
or at surface the width of the vehicle at the
height of the mark in Step 4.
Notice:Do not cover a headlamp to improve
beam cut-off when aiming. Covering a
headlamp may cause excessive heat build-up
which may cause damage to the headlamp.
6. Turn on the low-beam headlamps and place a
piece of cardboard or equivalent in front of the
headlamp not being adjusted. This allows
only the beam of light from the headlamp
being adjusted to be seen on the at surface.
476