brake AUDI A8 2013 Repair Manual

-Never mount used tires on your vehicle if
you are not sure of their "previous histo­
ry." Old used tires may have been dam­
aged even though the damage cannot be
seen that can lead to sudden tire failure
and loss of vehicle control.
- All four wheels must be fitted with radial
tires of the same type, size (rolling cir­
cumference) and the same tread pattern.
Driving with different tires reduces vehi­
cle handling and can lead to a loss of
control.
- If the spare tire is not the same as the
tires that are mounted on the vehicle -
for example with winter tires - only use
the spare tire for a short period of time and drive with extra care. Refit the nor­
mal road wheel as soon as safely possi­
ble.
- Never drive faster than the maximum
speed for which the tires on your vehicle
are rated because tires that are driven
faster than their rated speed can fail
suddenly.
- Overloading tires cause heat build-up,
sudden tire failure, including a blowout
and sudden deflation and loss of control.
- Temperature grades apply to tires that
are properly inflated and not over or un­
derinflated .
- For technical reasons it is not always
possible to use wheels from other
vehicles - in some cases not even wheels
from the same vehicle model.
- If you install wheel trim discs on the ve­
hicle wheels, make sure that the air flow
to the brakes is not blocked. Reduced air­
flow to the brakes can them to overheat,
increasing stopping distances and caus­
ing a collision.
- Run flat tires may only be used on
vehicles that were equipped with them
at the factory. The vehicle must have a
chassis designed for run flat tires. Incor­
rect use of run flat tires can lead to vehi­
cle damage or accidents. Check with an
authorized Audi dealer or tire specialist
to see if your vehicle can be equipped
Tires and wheels 263
with run flat tires. If run flat tires are
used, they must be installed on all four
wheels. Mixing tire types is not permit­
ted.
@ Note
- For technical reasons, it is not generally
possible to use the wheel rims from oth­
er vehicles. This can hold true for wheels
of the same vehicle type.
- If the spare tire is different from the
tires that you have mounted on your ve­
hicle (for example winter tires or wide
profile tires), then use the spare tire for a
short period of time only and drive with
extra care. Replace the flat tire with the
tire matching the others on your vehicle
as soon as possible.
- Never drive without the valve stem cap .
The valves could get damaged.
(® For the sake of the environment
Dispose of old tires in accordance with the
local requirements.
Uniform tire quality grading
-Tread wear
- Traction AA A B C
- Temperature ABC
Quality grades can be found where applicable
on the tire side wall between tread shoulder
and maximum section width
~ page 260,
fig. 208 .
For example: Tread wear 200, Traction AA,
Temperature A.
All passenger car tires must conform to Feder­
al Safety Requirements in addition to these
grades .
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
unde r contro lled conditions on a specified
government test course. •
•

26 6 T ire s and whee ls
- Remove snow chains before driving on
roads not covered with snow to avoid
damaging t ires and wearing the snow
chains down unnecessarily.
- Snow chains, which come into d irect con­
tact with the wheel rim, can scratch or
damage it. Therefore, make sure that the
snow chains are suitably covered . Check
the position of the snow chains after
driving a few yards and correct if neces­
sary. Follow the instructions from the
snow chain manufacturer when doing so.
- If the Adaptive Air Suspension should
malfunction, do not mo unt or use snow
cha ins beca use the veh icle will be ex­
tremely low. If you do drive with snow
chains on while the vehicle is at this lev­
el, the snow chains might severely dam­
age the wheelhouse and other parts of
the veh icle.
Where snow chains are mandatory oncer­
tain roads, this normally also applies to
veh icles with All Wheel Drive.
Wheel bolts
Wheel bolts must always be tightened to the
correct torque.
The design of whee l bolts is matched to the
factory installed rims. If different rims are fit­
ted, the correct wheel bolts with the r ight
length and correctly shaped bolt heads must
be used. This ensures that wheels are fitted
securely and that the brake system functions
cor rectly .
In certain circumstances, you may not use
wheel bolts from a different vehicle - even if it is the same model
~ page 298.
A WARNING
Imprope rly tightened o r maintained wheel
bolts can be come loose caus ing loss of control, a col
lision and serio us personal in­
jury.
- Always keep the wheel bo lts and the
threads in the whee l hubs clean so the
wheel bo lts can turn easily and be prop­
erly tightened.
- Never grease or oil the wheel bolts and
the threads in the wheel hubs. They can become loose while driv ing if greased or
oiled, even if t ightened to the specified
torque.
- Only use wheel bolts that belong to the rim being installed .
- Never use different wheels bolts on your
veh icle.
- Always ma intain the correct tightening
torque for the whee l bolts to reduce the
risk of a wheel loss. If the tightening tor­
que of the wheel bolts is too low, they
can loosen and come out when the vehi­
cle is mov ing. If the tig htening torq ue is
too high, the wheel bolts and threads
can be damaged and the whee l can be ­
come loose .
(D Note
The specified torque for the whee l bolts is
90
ft l b (120 Nm) with a tolerance of± 7,4
ft lb(± 10 Nm) . Torque whee l bolts diago ­
nally . After changing a whee l, the torque
must be checked as soon as possible with a
torque wrench -preferably by an author­
i zed Audi dealer or qualif ied workshop.
Low aspect ratio tires
Your Audi is factory-equ ipped w ith low aspect
ratio tires . These tires have been thoroughly
tested and been se lected specifically fo r your
model for their superb perfo rman ce, road fee l
and hand ling under a variety o f driving condi­
tions. Ask your authorized A udi dealer for
more details .
T he low aspect ratio of these tires is ind icated
by a numera l of
55 o r less in the tire's s ize
designation. The numeral rep resents the ratio
of the tire's sidewa ll height in relation to its
ll-

Spare wheel
Applies to vehicles: with spare wheel
The spare wheel is stored in the wheel well
underneath the floor panel in the luggage
compartment.
F ig. 21 6 Luggag e compartme nt: spare wheel
Taking out the sp are whee l
• Lift the cargo floor by the plast ic handle
c:> fig . 216.
• Hook the hand le into the luggage compart ­
ment weather strip .
• Turn the large screw
c:> fig. 216 counter­
clockwise.
• Take out the spare tire.
• Always store the vehicle tool kit, the jack*
and the replaced tire i n the luggage com­
partment
c:> page 140 .
• Unhook the ca rgo floor before closing the
rear lid.
& WARNING
Loose items in the passenger compa rt­
ment can cause serious pe rsonal in jury
during hard braking or in an accident.
- Never store the spare wheel or jack and
tools in the passenger compartment.
@ Tips
Check the inflat io n press ure of the spare
tire periodically to keep the tire ready for
use.
-
What do I d o now ? 273
Changing a wheel
Before changing a wheel
Observe the following precautions for your
own and your passenger's safety when chang­
ing a wheel.
• After you experience a tire failure, pull the
car well away from mov ing traffic and try to
reach
le vel ground before you stop c:> ,&.
• All passengers should leave the car and
move to a safe location (for ins tance, behind
t he guardra il)
c:> ,& .
• Engage the parking brak e to prevent your
vehicle from rolling unintentionally
c:> ,& .
• Move sele ctor lever to po sit ion Pc:> &_ .
• If you are towing a trailer, unhitch the trail­
er from your vehicle.
• Take the
jack and the spare tire out of the
luggage compartment
c:> page 271,
c:> page
272 .
& WARNING
You o r you r passengers could be i njured
while changing a wheel if you do not fo l­
low these safe ty pre caut ions :
-I f you have a flat tire, move a safe d is­
tance off the road. Turn off the e ngine,
turn the emergency flashers on and use
other warning devices to a lert other mo­
torists .
- Make sure that passengers wait in a safe
place away from the vehicle and well
away from the road and traffic.
- To help prevent the vehicle from moving
suddenly and possib ly slipping off the
jack, always full y set the parking brake
a nd b lock the wheel d iagonally opposite
the wheel be ing changed. When one
front wheel is lifted off the ground, plac­ ing the Au tomatic Transmission in "P"
( P ar k) will
not prevent the vehicle from
mov ing .
- Before you chang e a whee l, be s ure the
g round is level and firm. If necessary,
use a sturdy board un der the jac k.
-

276 What do I do n ow ?
ho ld on to the car to keep your ba lance
and take care not to slip .
Raising the vehicle
The vehicle must be lifted with the jack first
before the wheel can be removed .
Fig. 220 Sill panels : m ark ings
Fig . 22 1 Sill: posit ion ing t he veh icle jack
.. Activate the vehicle jack mode in the MMI:
I CAR ! function button > Ca r sys tem s control
button>
S ervicing & checks > Air susp .:
jack mod e > On .
.. Engage the parking brake to prevent your
vehicle from ro lling u ninten tionally.
.. Move the
se lector l ever to po siti on P .
.. Find the marking (imprint) on the sill that
is nearest the wheel that will be changed
o
fig. 220 . Behind the marking, there is a
lifting point on the s ill for the vehicle jack .
.. Turn the
ve hicle jack located under the lift­
ing point on the si ll to raise the jack until its
arm @o
fig. 221 is located under the des ­
i gnated plastic mount o ,& o0.
.. Align the jack so that its arm@o
fig. 221
engages in the designated lifting po int in
the door sill and the movable base @ lies
flat on the gro und. The base @ must be
ver­
tical
under the lifting point @. ..
Wind the jack up fu rther until the f lat t ire
comes off the ground o
.&,.
Position t he vehicle jack only under the desig ­
nated lifting points on the si ll
c:> fig. 220.
There is exactly one locat ion for each wheel.
The jack must not be positioned at any other location
c:> .&, c:>Q).
An un stable surfac e under the jack ca n cause
the vehicle to slip off the jack . Always provide
a firm base for the jack on the ground . If nec­
essary place a sturdy board or simi lar support
under the jack. On
hard, slipper y surfaces
(such as tiles) use a rubbe r mat or similar to
prevent the jack from slipping
c:> .&, .
A WARNING ~
-You or your passengers co uld be injured
while changing a wheel if you do no t fo l­
low these safety p reca utio ns:
- Position the vehicle jack on ly at the
designated lifting points and align the
jack. Otherwise, the vehicle jack co uld
slip and cause an injury if it does not
have sufficient hold on the vehicle.
- A soft or unstable surface under the
jack may cause the vehicle to slip off
the jack . Always prov ide a firm base for
the jack on the ground. If necessa ry,
u se a st urdy boa rd under the jack.
- On hard, s lippery su rface (such as t iles)
use a rubber mat or sim ilar to prevent
the jack from slipping.
- To help prevent injury to yo urself and
your p asse ngers:
- Do not raise the vehicle until you are
sure the jack is securely engaged.
- Passengers must not remain in the ve­
hicle when it is jacked up.
- Make sure that passengers wait in a
safe place away from the vehicle and
well away from the road and traffic .
- Make sure jack pos ition is correct, ad ­
just as necessary and then continue to
raise the jack.
- Changes in temperature or load can af­
fect the height of the vehicle.

CD Note
Do not lift the vehicle by the sill. Position
the vehicle jack only at the designated lift ­
ing points on the sill. Otherwise , your vehi­
cle will be damaged.
(D Tips
The vehicle jack mode switches off auto ­
matically at speeds above 10 km/h .
Taking the wheel off/installing the spare
Follow these instructions step-by-step for
changing the wheel.
Fig. 222 C h ang ing a w hee l: u sing t he sc rew drive r han ­
d le (w it h th e blade remov ed) to tu rn th e bolt s
Fig. 223 C h ang ing a w hee l: alig nme nt pin inside the
top hole
After you have loosened all wheel bolts and
raised the vehicle off the ground, remove and
replace the wheel as follows:
Removing the wheel
.. Use the hexagonal socket in the screwd riv­
er handle
to completely remove the top­
most wheel bol t and set it aside on a
clean
surface ¢ fig. 222 .
What do I do now? 27 7
.. Sc rew the threaded end o f the alignment
pin
from the tool kit hand-tight into the
empty bolt hole
¢ fig. 223 .
.. Then remove the other wheel bolts as de­
scribed above.
.. Take off the wheel leaving the alignment
pin in the bolt hole
¢(D .
Putting on the spare wheel
.. Lift the spare wheel and carefully slide it
over the alignment p in to guide it in place
¢ (]).
.. Use the hexagonal socket in the screwdriver
handle to screw in and tighten all wheel
bolts
slightly.
.,. Remove the a lignment pin and insert and
tighten the rema ining wheel bolt slightly
like the rest .
.. Turn the jack hand le counter-clockwise to
lower the vehicle until the jack is fully re­
leased .
.. Use the wheel bolt wrench to tighten all
wheel bolts f irmly
¢ page 2 75. Tighten
them
crosswise, from one bolt to the (ap ­
proximately) opposite one, to keep the
wheel cente red.
CD Note
When removing or installing the wheel,
the rim could hit the brake rotor and dam­
age the rotor. Work carefully and have a
second person help you.
@ Tips
Never use the hexagonal socket in the han­
dle of the screwdriver to loosen or tighten
the wheel bolts.
- Pull the reversible blade from the screw­
driver before you use the hexagonal
socket in the hand le to turn the wheel
bolts.
- When mount ing tires with
unidirectional
tread design
make sure the tread pat­
tern is pointed the right way
¢page 278.
- The wheel bolts shou ld be clean and easy
to turn. Check for dirt and corrosion on
the mating surfaces of both the wheel

280 Fuses and bulbs
Fuse panel @ (brown)
No. Equipment
1 Headlight control switch
2 Emergency start coil (key
identification)
3 Rear door
control module
(driver's side)
5 Horn
6 Interior lights
(headliner)
Steering column lever, mul-
8
tifunction steering wheel
controls, steering wheel
I heating
10 Power steering column ad-
justment
11 Driver door control module
12 Diagnost
ic connector, light/
rain sensor
14 Power steering column ad-
justment
15 Power
steering, A/C com-
pressor
16 Brake booster
Fuse panel © (black)
No. Equipment
1 Front seat heating
2 Windshield wiper
3 Front exterior lighting
4 Sun roof
5 Driver power window
6 Driver seat (pneumatic)
7 Panoramic
sunroof
8 Dynamic steering
9 Front exterior lighting
10 Windshield/headlight
wash-
er system
11 Rear power window (driver's
side)
Panoramic sunroof
Amps
5
5
7,5 15
7,5
10/5
5
7,5 10
25
20 15
Amps
30
30
30 20
30
7,5
20
35
30
35
30
40
Front passenger side cockpit fuse
assignment
Fig. 227 Front passe nger side cockpit: fuse pane l with
plastic bracket
Fuse panel ® (black)
No. Equipment Amps
1 Anti-theft alarm system
5
2 T
ransmission control mod-
15
ule
3 Front climate control fan 40
4 Engine supply 35
6 Engine
control module
5
7 Front passenger door con-
7,5
trol module
8 Front passenger
power win-
30
dow
9 ESC control module 10
10 E5C control modu le 25
11 Right rear power window
30
12 Front passenger
seat (pneu-
7,5
matics)

Fuse s and bulb s 281
Luggage compartment fuse assignment
Fig. 228 Luggage compartment: fuse pa nel with plastic bracket
Fuse panel @ (black ) Fuse panel @ (b la ck)
No . Equi pment Amps No. Equipment Amps
[ru button, data logger, diag-
11 Dynamic
steering
5
l nostic
connector, BCM -1,
5
Selector lever, BCM-2 5
adaptive light ing system
Audi side assist
5
2 Networking gateway 5
Engine control module 5
3 adaptive air suspension
5
Starter 40
4 Parking system 5
Left headlight/Headlight
16 10/5
5 Steer
ing column lever
5
range control system
6 Suspension control system
5 Fuse panel
@ (red ) sensor
Belt tensioners, airbag con-
No. Equipment Amps
7 trol module 5
l Left
reversible be lt tens ione r 25
Heated washer fluid nozzles, 2
Right reversible belt ten-
25
Homelink (garage door sioner
8 opener), night vision system 5 Starter diagnos
is, DC/DC
control module, sport differ-3 c onverter (Start-Stop-Sys-5
ential, ioni zer tern )
9
Electromechan ica l parking
5 4 DC/DC converter 7,5
brake contro l modu le 5 Image pro cessing 7 ,5 -
10
Rear seat heating, cooler, in-
5
terior rearview mirror

282 Fuses and bulb s
Fuse panel
® (red)
No. Equipment
=
I 6
Right headlight (headlight
with adaptive light)
7 ESC control module
8
Sound actuator, AEM control module
9 Adaptive cruise control
10 Transmission control mod
-
ule
11 Climate control system sen-
sors
Fuse panel © (brown)
No. Equipment
1
Electromechanical parking
brake
2 Suspension control system
sensor
3
Right rear door control mod-
ule
Smart modul tank
5
Front cl imate control system
contro ls
6
Rear climate control system
controls
7 Networking gateway
8 Cooler
9
Interface for specia l func-
tions
10 Cell phone adapter, Blue-
tooth handset
11 AEM contro
l module
12
13 Ambient
lighting
14 Rear exterior lighting
15 Fuel pump
I 16 Electromechanical parking
brake
Amps
=
10
5
7,5
10
5
5
5
5
7,5
5
15
10
5
15
5
5
15
10
10
20
25
30
-
Fuse panel @ (black)
No. Equipment
1
3
5
6
7
Automatic luggage com­ partment lid
Rear sockets
adaptive air suspens ion
115-V socket
Electromechanical parking
brake
8 Rear seat heating
9 Rear exterior lighting
10 Rear climate control system
blower
Rear sun shade, closing aid,
11 luggage compartment lock,
keyless go/entry, fuel filler
door
12 Luggage
compartment lid
control module
Fuse panel E (red)
No. Equipment
1 Rear seat adjustment but-
tons
3 Left rear seat (pneumatics)
5 Tra iler hitch control modu le*
6 Left rear seat
7 Right rear seat
8 Trailer hitch control module*
9 Trai ler hitch control modu le*
10 Right rear seat (pneumatics)
Fuse panel
® (brown)
No. Equipment
1 Start-Stop-System,
Radio re-
ceiver/sound amplifier
Sound amplifier
Start-Stop-System, Rear
3 Seat Entertainment, radio
receiver/sound amplifier
5 Automatic dimming interior
rearview mirror
6 DVD changer
Amps
5
20
15
25
30
25
20
20
20
30
Amps
5
7,5 20
30
30
20 15
7,5
Amps
30
30
10
5
5

@ Tips
- The discharged battery must be properly
connected to the vehicle's electrical sys­
tem. When jump start ing or charging the
battery, never connect the negative
ground cable to the battery negative post because the battery manager sys­
tem must be able to detect the battery's
state of cha rge. A lways connect the neg­
ative g round cab le to the negative
gro und post o f the battery manage r con­
trol uni t.
Use of jumper cables
Make sure to connect the jumper coble
clomps in exactly the order described below!
Fig. 229 Engine compartment: connecto rs for jump
start cables and charger
Fi g. 230 Jump start ing w ith the battery of another ve ­
hicle: @-booste r batte ry, @ -discharged vehicle bat ­
te ry
The procedure described below fo r connecting
jumper cab les is intended to provide a jump
start for your veh icle.
Vehicle with discharged batt ery:
.. Turn off lights and acc esso ries, move leve r
of automat ic t ransm ission to N (Neutral) o r
P (Park) and set pa rking brake .
Emergenc y situ ation s 285
Connect POSI TIVE(+) to POSITIVE (+ )
(red )
.. Open the red cover on the positive terminal
¢fig. 229.
1. Connect one end of the red positive cable
on the
jump sta rt bolt ¢ fig. 230 (D (bolt
under the red cover = "positive") of the ve­
hicle to be started @.
2. Co nnect th e other end to the pos itive ter-
mina l@ of the booster battery @.
Connect NEGATIVE( -) to NEGATIVE(-)
(black )
3. Connect one end of the black negative ca­ ble to the negat ive termina l@ of the
booster b attery @.
4 . Connect the othe r end to the
jump start
pin @ (bolts with hex head bolt = "nega­
tive") of the vehicle to be started @.
Starting the engine .. Sta rt the engine of the veh icle w ith the
booste r ba ttery @. Ru n the engine at a
moderate speed .
.. Start engine wit h discha rged vehicle battery
@ in the usual manner .
.. If the eng ine fails to start, do not keep the
starter cranking for longer than 10 seconds.
Wait for about 30 seco nds a nd the n try
aga in .
.. With engi ne runni ng, remove j umper cab les
from both vehicles in the exact
reverse o r­
de r .
.. Close the red cover on the positive term inal.
T he battery is vented to th e outside to p rev ent
gases from en ter ing the veh icle in ter io r. Ma ke
s ur e th at the j umper clamps are well connec t­
ed with their meta l parts in full con ta ct w ith
the battery term inals.
A WARNING
To avoid se rious personal injury and dam­
age to the veh icle, heed all warnings and
instructions of the jumper cable man ufac­
turer. If in doubt, call for road service .
- J umper cables m ust be long enough so
that the veh icles d o not touch.
-

286 Emergency situations
-When connecting jumper cables, make
sure that they cannot get caught in any
moving parts in the engine compar t­
ment .
- Before you check anything in the engine
compartment, always read and heed all
WARNINGS
c:> page 226 , Engine com­
partment.
(D Note
Improper hook-up of jumper cables can ru­
in the generator.
- Always connect POSITIVE(+) to POSI­
TIVE( +), and NEGATIVE( -) to NEGATIVE
( - ) ground post of the battery manager
control unit.
- Check that all screw plugs on the battery
cells are screwed in firmly . If not, tighten
plugs prior to connecting clamp on nega­
tive battery terminal.
- Please note that the procedure for con­
necting a jumper cable as described
above applies specifically to the case of
your vehicle being jump started. When
you are giving a jump start to another ve­
hicle, do
not connect the negative(-) ca­
ble to the negative(-) terminal on the
discharged battery ©
c:> fig. 230. In­
stead, securely connect the negative(-)
cable to either a solid metal component
that is firmly bolted to the engine block
or to the engine block itself . If the bat­
tery that is being charged does not vent
to the outside, escaping battery gas
could ignite and explode!
Emergency towing
with commercial tow
truck
General hints
Your Audi requires special handling for tow­
tng.
The following information is to be used by
commercial tow truck operators who know
how to operate their equipment safely.
-Never tow your Audi. Towing will cause
damage to the engine and transmission.
- Never wrap the safety chains or winch ca­
bles around the brake lines.
- To prevent unnecessary damage, your Audi
must be transported with a flat bed truck.
- To load the vehicle on to the flat bed, use
the towing loop found in the vehicle tools
and attach to the front or rear anchorage
c:> pag e 286 and c:> page 287.
.&_ WARNING
=
A vehicle being towed is not safe for pas-
sengers. Never allow anyone to ride in a
vehicle being towed, for any reason.
Front towing loop
Only install the front towing loop when it is
needed .
C7
0
Fig. 231 Front bumper: cover
Fig. 232 Front bumper : sc rewing in th e towin g loop
-
The towing loop fits into the threaded hole lo ­
cated on the right side of the front bumper
and covered by a small cover when not in use.
.,. Remove the towing loop from the veh icle
tool kit.