2007 HUMMER H2 wheel

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.
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 braking system — 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 do not,
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 have come to expect
can change in many other ways if someone puts in
the wrong replacement brake parts.
430

How to Check Lubricant
To get an accurate reading, the vehicle should be
on a level surface.
When the differential is cold, the proper level is
from 5/8 inch to 1-5/8 inch (15 mm to 40 mm)
below the bottom of the ller plug hole, located on
the rear axle. Add only enough uid to reach
the proper level.
What to Use
Refer to the Maintenance Schedule to determine
what kind of lubricant to use. SeeRecommended
Fluids and Lubricants on page 528.
Four-Wheel Drive
Transfer Case
It is not necessary to regularly check transfer case
uid unless you suspect there is a leak or you
hear an unusual noise. A uid loss could indicate
a problem. Have it inspected and repaired.
Refer to the Maintenance Schedule to determine
how often to change the lubricant. See
Scheduled Maintenance on page 517.
438

Daytime Running Lamps (DRL)
To replace a daytime running lamp bulb, do the
following:
1. Locate the lamp
assembly behind the
front bumper. It is
easiest to come
in from the side of
the vehicle
through the wheel
opening.
2. Turn the bulb socket counterclockwise and
remove it from the lamp housing.
3. Remove the bulb from the bulb socket.
4. Install the new bulb into the bulb socket.
5. Reinstall the bulb socket into the lamp housing
and turn it clockwise until it locks.
Roof Marker Lamps
Corner Roof Marker Lamps
To replace one of these bulbs, do the following:
1. Remove the screw and lift off the lens.
2. Turn the bulb socket counterclockwise to
remove it.
3. Remove the bulb.
4. Install a new bulb into the socket.
5. Reinstall the socket into the lens and turn it
clockwise to lock it into place.
6. Hook the side of the lens with the hook end into
the notch rst and then tighten the screw.
443

Tire Size
The following examples show the different parts of
a tire size.
(A) Passenger (P-Metric) Tire:The United
States version of a metric tire sizing system.
The letter P as the rst character in the tire size
means a passenger vehicle tire engineered
to standards set by the U.S. Tire and Rim
Association.(A) Light Truck (LT-Metric) Tire:The United
States version of a metric tire sizing system.
The letters LT as the rst two characters in the
tire size means a light truck tire engineered to
standards set by the U.S. Tire and Rim Association.
(B) Tire Width:The three-digit number indicates
the tire section width in millimeters from sidewall
to sidewall.
(C) Aspect Ratio:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the light truck (LT-Metric) tire
illustration, it would mean that the tire’s sidewall is
75 percent as high as it is wide.
(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire.
The letter R means radial ply construction;
the letter D means diagonal or bias ply construction;
and the letter B means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.
Passenger (P-Metric) Tire
Light Truck (LT-Metric) Tire
452

How to Check
Use a good quality pocket-type gage to check
tire pressure. You cannot 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.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 459
andWheel Replacement on page 464for
more information.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, use the wheel wrench to tighten the wheel
nuts. SeeChanging a Flat Tire on page 468.
The purpose of regular rotation is to achieve
more uniform wear for all tires on the vehicle.
The rst rotation is the most important.
SeeScheduled Maintenance on page 517.
457

When rotating your vehicle’s tires, always use
one of the correct rotation pattern shown here.
The ve-tire rotation pattern includes a full-size
spare tire and wheel assembly that matches
the regular road tires and wheels in size, type,
and brand.
After the tires have been rotated, adjust the front
and rear ination pressures as shown on the
tire and loading information label. SeeLoading
Your Vehicle on page 362andInation - Tire
Pressure on page 456, for more information.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specications on page 512.
Four-Tire Rotation Pattern
Five-Tire Rotation Pattern
458

{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 468.
When It Is Time for New Tires
One way to tell when it
is time for new tires is
to check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining. Some
commercial truck tires
may not have treadwear
indicators.
You need a new tire if any of the following
statements are true:
You can see the indicators at three or more
places around the tire.
You can see cord or fabric showing through
the tire’s rubber.
The tread or sidewall is cracked, cut or
snagged deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage
that cannot be repaired well because of the
size or location of the damage.
459

Buying New Tires
GM has developed and matched specic tires
for your vehicle. The original equipment tires
installed on your vehicle, when it was new,
were designed to meet General Motors Tire
Performance Criteria Specication (TPC spec)
system rating. If you need replacement tires,
GM strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to
give the same performance and vehicle safety,
during normal use, as the original tires.
GM’s exclusive TPC Spec system considers over
a dozen critical specications that impact the
overall performance of your vehicle, including
brake system performance, ride and handling,
traction control, and tire pressure monitoring
performance. GM’s TPC Spec number is molded
onto the tire’s sidewall by the tire manufacturer.
If the tires have an all-season tread design,
the TPC spec number will be followed by a MS,
for mud and snow. SeeTire Sidewall Labeling on
page 449for additional information.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different
sizes, brands, or types (radial and
bias-belted tires) the vehicle may not
handle properly, and you could have a
crash. Using tires of different sizes, brands,
or types may also cause damage to your
vehicle. Be sure to use the correct size,
brand, and type of tires on your vehicle’s
wheels.
{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges could develop
cracks after many miles of driving. A tire
and/or wheel could fail suddenly, causing
a crash. Use only radial-ply tires with the
wheels on your vehicle.
460