Page 318 of 450

Black plate (24,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/12
10-24 Vehicle Care
Brakes
This vehicle has 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 can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair. Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the 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 torque
specifications in
Capacities and
Specifications on page 12‑2.
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
that brake service might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the 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. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes —for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.
Page 339 of 450

Black plate (45,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/12
Vehicle Care 10-45
(50 mi); and a heavy load 45 km
(25 mi). As soon as possible,
contact the nearest authorized GM
or run-flat servicing facility for
inspection and repair or
replacement.
When driving on a deflated run-flat
tire, avoid potholes and other road
hazards that could damage the tire
and/or wheel beyond repair. When a
tire has been damaged, or driven
any distance while deflated, check
with an authorized run-flat tire
service center to determine whether
the tire can be repaired or should be
replaced. To maintain the run-flat
feature, all replacement tires must
be run-flat tires.
To locate the nearest GM or run-flat
servicing facility, call Customer
Assistance.
The valve stems on run-flat tires
have sensors that are part of the
TPMS. SeeTire Pressure Monitor
System on page 10‑52. These
sensors contain batteries that are
designed to last for 10 years under normal driving conditions. See
your dealer for wheel or sensor
replacement.
Notice:
Using liquid sealants can
damage the tire valves and tire
pressure monitor sensors in the
run-flat tires. This damage is not
covered by the vehicle warranty.
Do not use liquid sealants in
run-flat tires.
Summer Tires
This vehicle may come with high
performance summer tires. These
tires have a special tread and
compound that are optimized for
maximum dry and wet road
performance. This special tread
and compound will decrease
performance in cold climates, and
on ice and snow. We recommend
installing winter tires on the
vehicle if frequent driving in cold
temperatures or on snow or ice
covered roads is expected. See
Winter Tires on page 10‑44.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
examples show a typical
passenger tire sidewall.
Passenger (P-Metric) Tire Example
(1) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size” illustration later in this
section for more detail.
Page 341 of 450

Black plate (47,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/12
Vehicle Care 10-47
Tire Designations
Tire Size
The following is an example of a
typical passenger vehicle
tire size.
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width
:The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall. (3) Aspect Ratio
:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item 3 of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
(4) 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.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples
of optional accessories are
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Page 358 of 450

Black plate (64,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/12
10-64 Vehicle Care
{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. Always use the correct
wheel, wheel bolts, and wheel
nuts for replacement.
Notice: The wrong wheel can
also cause problems with bearing
life, brake cooling, speedometer
or odometer calibration,
headlamp aim, bumper height,
vehicle ground clearance, and tire
clearance to the body and
chassis.
{WARNING
Rust or dirt on a wheel, or on
the parts to which it is
fastened, can make wheel
nuts become loose after a
time. The wheel could come
off and cause a crash. When
changing a wheel, remove any
rust or dirt from places where
the wheel attaches to the
vehicle. In an emergency, a
cloth or a paper towel can be
used, however, use a scraper
or wire brush to remove all
rust or dirt.
{WARNING
Never use oil or grease on studs
or the threads of the wheel nuts.
The wheel nuts might come loose
and the wheel could fall off,
causing a crash.
{WARNING
Incorrect wheel nuts or improperly
tightened wheel nuts can cause
the wheel to become loose and
even come off. This could lead to
a crash. Be sure to use the
correct wheel nuts. If you have to
replace them, be sure to get new
GM original equipment
wheel nuts.
Notice: Improperly tightened
wheel nuts can lead to brake
pulsation and rotor damage. To
avoid expensive brake repairs,
evenly tighten the wheel nuts in
the proper sequence and to the
proper torque specification.