2021 AUDI A4 brake rotor

Driving

This message appears when specific conditions
are not met during a Stop phase. The Start/Stop
system will not be able to restart the engine. The
engine must be started with the
START ENGINE STOP] button.


Vehicle starting system: malfunction! Please
contact Service
There is a malfunction in the Start/Stop system.
Drive the vehicle to an authorized Audi dealer or
authorized Service Facility as soon as possible to
have the malfunction corrected.
Brakes
General information
You can apply the vehicle's brakes using the brake
pedal.
Operating noise
Noises may occur when braking depending on the
speed, braking force, and outside conditions such
as temperature and humidity.
Braking effect
The response time from the brakes depends on
the weather and environmental conditions. To
ensure the optimal braking effect, the brake sys-
tem is cleaned at regular intervals. This is done
by applying the brake pads to the brake rotors for
a short period of time when driving at high
speeds when the windshield wipers are switched
on.
If the brake system becomes damp, for example
after driving in heavy rain, the braking effect may
be delayed. Other factors that could temporarily
increase the response time of the brakes include:
— Wet conditions
— Low temperatures, ice, and snow
— Roads covered in salt
— Dirty brake pads
Corrosion
Corrosion may form on the brake rotors if there is
no heavy braking, if the vehicle is not driven for
long periods of time, or if the vehicle is not driv-
en
frequently or for long distances. In this case,
104
braking heavily several times while driving at
high speeds can clean the brake rotors > A\.
Brake pads
New brake pads do not achieve their full braking
effect during the first 250 miles (400 km). They
must be “broken in” first. However, you can com-
pensate for the slightly reduced braking force by
pressing firmly on the brake pedal. Avoid heavy
braking during the break-in period.
Brake pad wear depends largely on the way the
vehicle is driven and on operating conditions.
Brake pad wear increases when driving frequently
in the city or short distances or when using a very
sporty driving style.
Ceramic brakes
Applies to: vehicles with ceramic brakes
Ceramic brakes provide excellent deceleration
rates.
The break-in period for new ceramic brakes may
be significantly longer than for standard brake
rotors. Due to the properties of the material,
they may cause noises at lower speeds. Ceramic
brakes also absorb more moisture in wet condi-
tions. Therefore, there will temporarily be less
braking force than when the brakes are dry. You
can compensate for this by pressing the brake
pedal harder.
Automatic post-collision braking system
The automatic post-collision braking system can
help to reduce the risk of sliding and of addition-
al collisions after an accident. If the airbag con-
trol module detects a collision, the vehicle is
braked by the ESC.
The vehicle does not brake automatically if one of
the following occurs:
— The driver presses the accelerator pedal, or
— The braking force generated by the pressed
brake pedal is greater than the braking force
that would be initiated by the system
— The ESC, the brake system, or the vehicle elec-
trical system is not functioning

Care and cleaning


follow the instructions from the car wash
operator.
—To reduce the risk of cuts, protect yourself
from sharp metal components when wash-
ing the underbody or the inside of the wheel
housings.
— After washing the vehicle, the braking effect
may be delayed due to moisture on the
brake rotors or ice in the winter. This in-
creases the risk of an accident. The brakes
must be dried with a few careful brake appli-
cations.

@) Note
— If you wash the vehicle in an automatic car
wash, you must fold the exterior mirrors in
to reduce the risk of damage to the mirrors.
—To reduce the risk of paint damage, do not
wash the vehicle in direct sunlight.
—To reduce the risk of damage, do not wash
decorative decals* with a pressure washer.
—To reduce the risk of damage to the surface,
do not use insect removing sponges, kitchen
sponges, or similar items.
— When washing matte finish painted vehicle
components:
— To reduce the risk of damage to the sur-
face, do not use polishing agents or hard
wax.
— Never use protective wax. It can destroy
the matte finish effect.
— Do not place any stickers or magnetic
signs on vehicle components painted with
matte finish paint. The paint could be
damaged when the stickers or magnets
are removed.
Power folding exterior mirrors* must only
be folded in and out using the power folding
function.
—To reduce the risk of damage to the rims
and tires, compare the width between the
wheels on your vehicle with the distance be-
tween the guide rails in the car wash.
—To reduce the risk of damage, compare the
height and width of your vehicle with the
height and width of the inside of the car
wash.
(*) For the sake of the environment
Only wash the vehicle in facilities specially de-
signed for that purpose. This will reduce the
risk of dirty water contaminated with oil from
entering the sewer system.
Cleaning and care information
When cleaning and caring for individual vehicle
components, refer to the following tables. The
information contained there is simply recommen-
dations. For questions or for components that
are not listed, consult an authorized Audi dealer
or authorized Audi Service Facility. Also follow
the information found in > A.
Exterior cleaning



Component Situation Solution
Windshield wiper | Deposits Soft cloth with glass cleaner, > page 59
blades
Headlights/ Deposits Soft sponge with a mild soap solution®
tail lights
Sensors/ Deposits Sensors: soft cloth with a solvent-free cleaning product
camera lenses Camera lenses: soft cloth with an alcohol-free cleaning sol-
ution
Snow/ice Hand brush/solvent-free de-icing spray >

256

Emergency assistance

The wheel bolts must be clean and loosen and
tighten easily. Check the contact surfaces for the
wheel and hub. Contaminants on these surfaces
must be removed before installing the wheel.

ZA\ WARNING
— Read and follow the important information
and notes under > page 242.
— Never use the hex socket in the screwdriver
handle or the hex socket wrench with the
ratchet to loosen or tighten the wheel bolts.
This increases the risk of an accident, be-
cause you will not be able to achieve the cor-
rect tightening specification.
@) Note
When removing or installing the wheel, the
rim
could hit the brake rotor and damage the
rotor. Work carefully and have a second per-
son help you.
Unidirectional tires
A unidirectional tire profile is identified by arrows
on the tire sidewall that point in the running di-
rection. You must always maintain the specified
running direction. This is necessary to ensure the
tire's optimal performance in regard to adhesion,
running noise, and friction, and to reduce the risk
of hydroplaning.

To benefit fully from the advantages of the uni-
directional tire design, you should replace faulty
tires as soon as possible and restore the correct
running direction on all of the tires.
> Reinstall the caps on the wheel bolts if necessa-
ry.
> Store the vehicle tool kit in its designated
place.
> If the removed wheel does not fit in the spare
wheel well, store it securely in the luggage
compartment > page 83.
> Check the tire pressure on the installed wheel
as soon as possible.
> Correct the tire pressure and store it in the MMI
=> page 254.
266
> The wheel bolt tightening specification must be
90 ft lbs (120 Nm). Have it checked as soon as
possible with a torque wrench. Drive carefully
until then.
> Have the faulty wheel replaced as quickly as
possible.
Space-saving spare tire
Applies to: vehicles with space-saving spare tire (Compact
spare tire)
The spare tire is intended for short-term use only.
Have the damaged tire checked and replaced if
necessary by an authorized Audi dealer or author-
ized Audi Service Facility as soon as possible.
There are some restrictions on the use of the
compact spare tire. The compact spare tire has
been designed specifically for your type of vehi-
cle. Do not replace it with the spare tire from an-
other type of vehicle.
The compact spare tire is located in the luggage
compartment under the cargo floor cover
=> page 261.
The tire pressure must be adjusted to a specified
value listed on the tire pressure sticker
=> page 245, fig. 168.
Snow chains
For technical reasons, the use of snow chains on
the compact spare tire is not permitted.
If you have to drive with snow chains and a front
tire fails, mount the spare tire in place of a rear
tire. Install the snow chains on the rear tire that
you removed, and install that in place of the
front tire that failed.

ZA\ WARNING
— After installing a spare tire, the tire pressure
must be checked as soon as possible.
— Do not drive faster than SO mph (80 km/h)
with a compact spare tire. Driving faster
than that increases the risk of an accident.
— To reduce the risk of an accident, avoid hard
acceleration or braking and driving fast
around curves with the compact spare tire.
— To reduce the risk of an accident, never drive
with more than one compact spare tire. >