brake AUDI A8 2016 Service Manual

Operating noi se
Noises may occur when braki ng depend ing on the
speed, braking force and outside cond itions s uch
as temperature and humidity.
Due to the na ture of t he mate ria ls used in ce ram­
ic bra ke rotors*, noises m ay become mo re appa­
ren t at low speeds.
Effect of wat er and road salt
In ce rtain situat ions, for example after driving
through water, in heavy ra in, afte r ove rnig ht con­
densat ion or after washing your car, the braking
effe ct can be red uced by moisture or ice on the
b rake rotors and brake pads. The brakes must be
dried first w ith a few careful brake applications .
At highe r speeds and with t he windsh ie ld wipers
turned o n, the bra ke pads p ress against the bra ke
rotors for a short amount of time . This occ urs at
regular intervals without the driver noticing and
provides for better bra ke response time under
wet conditions.
The effectiveness of the brakes can be reduced
when the vehicle is dr iven on a salt-covered road
and the brakes are not used. L ikewise, you clean
off accumu lated salt coat ing from brake discs
and pads with a few cautious applications of the
brake
c::> ,& .
Due to their sur face characteristics, ceramic
brake rotors* absorb mo isture in such condit ions.
This can cause a temporary reduction in braking
force compared to dry brakes. You can compen­
sate for this by pressing the brake peda l harder.
Cor rosion
There may be a tendency for dirt to b uild up on
the brake pads and corros ion to form on the discs
if the car is not driven regularly or only for short
tr ips with little use of the brakes.
If the brakes are not used frequently, or if corro­
sion has formed on the discs, it is adv isable to
clean off the pads and discs by brak ing firmly a
few t imes from a moderately high speed
c::> ,& .
Sma rt Technology
Faults in the brake system
If you s hou ld notice a sudden increase in br ake
peda l travel, then one of the two bra ke circu its
may have fai led
c::> ,& .
Low brake fluid level
Malfunctions ca n occu r in the brake system if the
brake fluid level is too low . T he brake flu id leve l
is monitored elect ronically.
Brake boost er
The brake booster works w ith vacuum pressure
wh ich is created only when the engine is runn ing
c::> ,& .
Brake lining wear status
Brake lining wear may be checked by visua l in­
spect ion of the cond ition of the brake pads
t hr ough the openings in the wheel. If necessary,
the wheel may be removed for t his inspection
c::> page 259, Replacing wheels .
.8_ WARNING
-New b rake p ads don't h ave the bes t stop­
p ing power an d must be "broken-in" during
the initial 250 miles (400 km) . The break-in
pe riod can be considerably longer for
veh icles with ceramic brake rotors*. You can
compensate for this by pressing the brake
pedal more firmly. This also applies late r
when new pads are installed.
- You shou ld perform braking maneuvers for
the purpose of cleaning the brake system only i f road co ndit ions pe rmit . Other road
users m ust not be put at r is k -you may
cause an ac cident!
- Before descending a steep g rade, reduce
speed and sh ift transmission into a lower
gear o r lower dr iving range. Do not r ide the
b ra kes or hold the pe dal down too long or
too often. This cou ld cause the b rakes to ge t
hot and dimin ish b raking effic iency .
- Do not " ride the bra kes" by rest ing you r foot
on the pedal when you do no t intend to
brake. This may cause the brakes to over­
heat, premature wear and increased stop­
p ing distance.
193

Smart Techn olo gy
- Under certain climatic and operating condi­
tions such as passing through water, driving
in heavy rain or after washing the vehicle,
the effectiveness of the brakes can be re­
duced . In w inter, ice can accumulate on the
brake pads, linings, discs and drums . Care­
fully apply brakes fo r a tes t. Brakes w ill dry
and ice coatings wi ll be cleaned off after a
few careful brake applications .
- Driving for an extended pe riod of time on
salt-covered roads witho ut using your
brakes can also affect bra king efficiency.
Clean off accumulated salt coating from
brake discs and pads with a few carefu l
brake applications.
- If you damage the front spoiler, or if you in­
stall a different spoiler, be sure the air flow
to the front brakes is not obstructed. Other­
wise the brake system could overheat reduc­
ing the effectiveness of the entire brake sys­
tem.
- Failure of one brake circuit will impair the
braking capability result ing in an increased
stopp ing distance. Avoid driving the vehicle
and have it towed to the nea rest Aud i dealer
or qualified workshop.
- Never let the vehicle roll to a stop with the
engine shut off.
- If the brake booster is not working, the
brake pedal must be pressed considerably
harder to make up for the lac k of booster
assistance.
Electromechanical power
assist, dynamic steering
The electromechanical power assist helps the
driver when steering.
Power steering adapts electronically based on
the vehicle speed.
Ind icator light s and messages
• Stee ring defective! St op th e ve hicle
If th is ind icator light turns on and stays on and
this message appears, the power steer ing may
have fa iled.
194
Do not continue driving. See your authorized
Audi dealer or other qualified repair facility for
ass istance .
,Ion Steering : System faul t You can c ontinue
dri ving
If the indicato r light turns on and the message
appears, the steeri ng may be more diff icult to
move o r more sensitive than usu a l. T he steer ing
whee l may also be at an angle when driving
straight.
D rive slowly to your a uth orized Aud i dea ler or
qualified wo rkshop to have the malfunct ion cor­
rected.
1;r,ij D ynamic steering : Init ializing
If this driver message appears and the indicator
light is flashing on the instrument panel, dynam­
i c steer ing* is being re initialized . After starting
the engine, t he steering wheel w ill move slightly.
Re- initializa tion might be necessary if the steer­
i ng whee l was moved hard to the left and right
while the vehicle was not moving . The display
goes out as soon as initialization is comp lete .
D rive slowly to your a uth orized Aud i dea ler or
qualified wo rkshop to have the mal func tion cor­
rected.
.&_ WARNING
Have the dynamic steering * system malfunc­
tion repaired as soon as possible by an au­
thorized Audi dealer or qualif ied workshop -
risk of acc ident!
(D Tips
If the . or ,Ion indicator light only stays on
for a short time, you may continue driving.
- The dynamic steering* stabi lity systems are
not ava ilable in the event of a system mal­
function.
- For additiona l information on dynamic
steering *, refer to~
page 106 .

Driving and the
environment
Breaking in
New eng ine
The engine needs to be run-in during the first
1,000 miles (1 ,500 km).
For the first 600 miles (1 ,000 kilometers):
"' Do not use full throttle .
"' Do not drive at engine speeds that are more
than 2/3 of the max imum permitted RPM .
"' Avoid high eng ine speeds.
From 600 to 1 ,000 miles (1,000 to 1,500
kilometers ):
"' Speeds can gradually be increased to the maxi­
mum pe rm issib le road or e ngine speed.
During and after b reak-in period
"' Do not rev the engine up to high speeds when it
is cold . This applies whether the transmission is
in N (Neutral) or in gear .
After the bre ak-in period
"' Do not exceed maximum engine speed under
any circumstances .
"' Upshift into the nex t higher gear
before reach­
ing the red area at the end of the tachometer
sca le
c:::;, page 10.
During the first few hours of driving , the eng ine's
internal friction is higher than later when all the
mov ing parts have been broke n in. How well this
b reak-in process is done depends to a considera­
b le exte nt o n the way the veh icle is d rive n du ring
the first 1,0 00 miles (1,500 kilome ters).
(D Note
E xtremely high eng ine speeds a re au toma ti­
cally reduced. However, t hese rpm li mits are
p rogr amme d fo r an eng ine well run-in, not a
new engine .
Driving and the envir onment
{® For the sake of the environment
Do not drive with unnecessarily high engine
spe eds -upshifting early saves fuel, red uces
no ise and protects the environment.
New tires
If your vehicle is runni ng on new tires, drive par­
t icularly careful for the first 3S0 m iles (500 kilo ­
meters) after fitting .
_&. WARNING
New tires tend to be slippe ry and mus t also
b e "bro ken- in". Be sure to remembe r th is dur­
i ng the first 350 m iles ( 500 k ilome ters).
Brake gent ly . Avoid following closely behin d
other vehicles or other s ituations that might
require sudden, hard braking.
Avoid damaging the
vehicle
When you are dr iv ing on poor roads, or over
curbs, steep ramps, etc., make certai n that low ­
ly ing parts such as spo ile rs and exhaust system
parts do not bottom o ut and get damaged .
This is espec ially true for veh icles with low-s lung
chass is (sports c hass is)* and fully loaded
vehicles .
Catalytic converter
Applies to: vehicles with gasoline engine
It is very important that your emission control
system (catalytic converter) is functioning prop ­
erly to ensure that y our vehicle is running in an
environmen tally sound manner.
"' Always use lead-free gasoline c:::;, page 212,
F uel supply .
"' Never run t he tank down all the way to emp ty.
"' Never put too much motor o il in yo ur engine
c:::;, page 225, Adding engine oil ce:r..
"' Never try to push- or tow-start your vehicle.
T he ca talytic co nverter is an efficient "cle an-up"
device built into the exhaust sys tem o f th e vehi -
-
cle. The catalytic converter b urns many of the .,.
197

Driving through water on
roads
Note the following to avoid vehicle damage when
driving through water, for example on flooded
roads:
- The water must not be any higher than the bot­
tom of the vehicle body.
- Do not drive faster than wa lking speed.
A WARNING
After driving through water, mud, slush, etc.,
the brakes may be slow to take effect because
of wet brake rotors and pads . Dry the brakes
first by brak ing carefully to restore the full
brak ing effect.
([) Note
-Vehicle components such as the engine,
transm ission, suspension or electrical sys ­
tem can be severely damaged by driving
th rough water.
- Always switch off the Sta rt-Stop-System*
whe n driving through water¢
page 85 .
(D Tips
-Check the depth of the water before driving
through it.
- Do not stop the veh icle, dr ive in reverse or
switch the eng ine off when dr iving through
wa ter .
- Keep in mind that oncoming ve hicles may
create waves that raise the water level and
make it too deep for your vehicle to drive
th rough safely.
- Avo id driving through salt water because it
can cause corrosion.
Driving and the envir onment
Economical and environ­
mentally-friendly driving
General
Your personal style of driving will determine the
economy of your vehicle, as well as exhaust and
nois e levels .
Fuel economy, e nv ir onmental impact, and wear
o n your eng ine, brakes and tires large ly depend
on three factors:
- your personal driving style
- operat ing cond itions
- technical limitations
If you anticipate what you need to do next and
drive economically, you can easily cut your fuel
consumption by 10-15 percent. Th is section will
give you some tips on how you can help the envi­
ronment and your pocketbook .
(D Tips
The consumption estimates as published by
ENVIRONMENTAL PROTECTION AGENCY
(EPA) and Transport Canada may not corre­
spond to your actual consumption on the
r oad, which w ill vary depending upon vehicle
l oad and speed, road and weather conditions,
trip length , etc.
Drive smoothly and keep a lookout ahead
Vehicles use the most fuel when they are acceler­
ating.
.,. Avoid unnecessary accelerat ing and braking .
Vehicles use the most fuel when they are acceler­ at ing . If you anticipate what is going to happen
next, you w ill need to brake less and, thus, accel­
erate less. Let the vehicle coast whenever possi­
ble - for example when you see that the next traf­
fic lig ht is red.
199

Trail er mode
Trailer mode
Driving with a trailer
General information
Your Audi was designed primarily for passenger
transportation.
If you plan to tow a trailer, please remember that
the additional load will affect durability, econo­
my and performance.
Trailer towing not only places more stress on the
vehicle, it also calls for more concentration from the driver.
For this reason, always follow the operating and
driving instructions provided and use common
sense.
(D Note
If you are going to tow a trailer, you must ac­
tivate the trai ler operation mode
¢ page 202, Operating instructions.
Technical requirements
Tr ailer hitch
Use a weight-carrying hitch conforming to the
gross trailer weight. The hitch must be suitable
for your veh icle and trailer and must be mounted
securely on the vehicle's chassis at a
technically
sound
location . Use only a trailer hitch with a re­
movable ball mount . Always check w ith the t rail­
er h itch man ufact urer to make sure that you are
using the co rrect hitc h.
Do not u se a bumper hitch .
The hitch must be installed in such a way that it
does not interfere with the impact-absorbing
bumper system . No mod ificat ions should be
made to the vehicle exhaust and brake systems .
F rom t ime to t ime, check that a ll hitch mo unt ing
bolts rema in securely fastened.
When you are not tow ing a traile r, remove the
tra iler hitch ball mount. This prevents the hitch
from caus ing damage should your vehicle be
struck from behind
¢ ,&. .
202
Trailer b rakes
If your trailer is equipped with a braking system,
check to be sure that it co nforms to all regu la­
tions.
The tra iler hydrau lic brake system must not be
directly connected to the vehicle's hydrau lic
brake system .
Safety chains
Always use safety chains between your vehicle
and the tra iler.
Trailer light s
Trailer lights must meet all regulations. Be sure
to check with your Aud i dealer for correct wir ing,
switches and relays .
Mirror s
If you are unable to see the traffic behind you us­
ing the regular outside mirrors, then you
must in­
stall extended mirrors . It is important that you
always have clear vision to the rear.
A WARNING
Afte r remov ing the tra iler hitch, do not sto re
i t in you r vehicle. In case of s udden braking,
the hitch could fly fo rwa rd and injure you or
your passengers.
Operating instructions
Fig. 1 87 MMI d ispl ay: tow ing mode o n
Maximum traile r weight
A tra iler for your vehicle is lim ited to a typical
class 1 or class 2 trailer.

Trailer load distribution
Be sure the load in the trailer is held securely in
p la ce to prevent it from sh ifting forward, back­
ward or sideways.
Never allow a passenger to ride in a trailer¢.&.
in Driving instructions on page 204.
Engine cooling system
Towing a trailer makes the engine work harder . It
is important that the cool ing system's perform­
ance is up to the addit ional load. Make sure that
the cooling system has enough fluid.
Tire pressure
When towing a trailer, inflate the tires of your
veh icle to the cold tire pressure listed under "Full
load " on the label located on the driver's side B­
pillar (vis ible when the door is open). Inflate
trailer tires to trailer and tire manufacturers'
specif ications.
Lights
Check to make sure both vehicle and trailer lights
are working proper ly.
Safety chains
Be sure trailer safety chains are properly connect­
ed from the trailer to the hitch on the vehicle.
Leave enough slack in the chains to permit turn­
in g corners . When you install safety cha ins, make
sure they wi ll not drag on the road when you are
driving.
The chains should cross under the trailer tongue
to prevent it from dropping in case of separat ion
from the hitch.
Adjusting the Audi drive select
Make sure the vehicle is on a level surface before
hitching up the trailer and before adjusting the
tongue we ight. The vehicle must be in
auto or
comfort driving mode and not ra ised
¢ page 106, 9Q) .
Make sure that the vehicle is lowered. In Info­
tainment, select:
I CARI function button > lower
control button .
Trailer mode
If you must drive under poor road conditions, you
can raise the vehicle
after coupling the trailer or
after adjusting the tongue weight¢ page 108.
(D Note
-Changes in temperature or load can affect
the height of the vehicle.
- Always select auto or comfort mode. Other­
w ise, the tong ue load specified for your ve­
hicle will no longer be applicable .
Driving instructions
Driving with a trailer always requires extra care
and consideration.
T o obtain the best possible handling of veh icle
and trailer, p lease note the following:
.,. Do not tow a loaded trailer when your car itself
is not loaded.
.,. Be especially careful when passing other
vehicles.
.,. Observe speed limits.
.,. Do not drive at the maximum permissible
speed .
.,. Always apply brakes early.
.,. Monitor the temperature gauge.
Weight distribution
Towing a loaded tra iler with an empty car results
in a highly unstab le distribution of weight . If this
cannot be avoided, drive at very low speeds only
to avoid the risk of losing steering control.
A "balanced" rig is easier to operate and control.
This means that the tow vehicle shou ld be loaded
to the extent possib le and permissib le, while
keeping the trailer as light as possible under the
cir cumstances . Whenever poss ible, transfer
some cargo to the luggage compartment of the
tow veh icle while observing tongue load require­
ments and vehicle load ing conside rations.
Speed
The higher the speed, the more difficult it be­
comes for the driver to control the r ig. Do not
drive at the maximum permissible speed. Reduce
your speed even more if load, weather or wind .,._
203

Trailer mod e
conditions are unfavorable - particularly when
going downhill.
Red uce veh icle speed
imm ediatel y if the tra ile r
shows the s lightest sign of swaying.
Do not try
to stop the sway in g b y accele rating .
Observe speed lim its . In some areas, speeds for
ve hicl es towing tra ilers are lower than for reg ula r
veh icles.
A lways apply brakes early . When dr iving down­
h ill , sh ift into a lower gear to use the engine
b raking effect to slow the veh icle. Use of the
brakes a lone can cause them to overheat and fail.
Air suspension*
When driving with a tra iler, activate the trailer
mode of the air suspension . Switch the air sus­
pens ion tra iler mode on when you a re towing a
tra ile r. This will limit the regulat ion by the air
suspens ion while driving . Select in the MM I:
ICARI function button > (Car )* sys tem s control
button >
Vehicle setting s > Air su sp .: to wi ng >
On .
Coolant temperature
The coolan t temperature gauge¢ page 10 must
be observed carefully. The coo lant temperature
can increase if you drive on long inclines in a low
gear at high engine speeds. Reduce your speed
immed iate ly if the LEDs in the top part of the dis­
p lay turn on.
For more information about indicator lights, re­
fer to.
¢page 15.
A WARNING
Anyone not properly restrained in a moving
vehicle is at a much greater risk in an acci­
dent. Never let anyone ride in your car who is
not properly wearing the restraints provided
by Audi.
Trailer mode notes
Important to know
Your vehicle hand les different ly when towing a
trai ler because of the additiona l weight and dif­
ferent weight distr ibut ion. Safety, performance
204
-
and economy will g reatly depend on how carefu l­
l y you load your trai ler and operate your rig .
Befo re yo u actually tow yo ur t railer, pract ice
turning, stopping and backing up in an area away
from traffic. Keep practicing unti l you have be ­
come complete ly familiar with the way your vehi­
cle-tra iler combination behaves and responds .
Backing up is diff icult and requ ires practice.
Backing up with a trailer genera lly req uires steer ­
ing action opposite to that when backing up your
vehicle witho ut a trailer .
Maintain a greater distance between yo ur vehicle
and the one in front of you. You will need more
room to stop . To compensate for the trailer, you
will need a larger than normal turning radius .
When passing, remember tha t you canno t accel­
erate as fast as you normally wou ld because of
the added load . Make sure you have enough room
to pass. After passing, allow p lenty of room for
your trailer before changing lanes again.
Avoid jerky starts, sharp turns or rapid lane changes.
(D Tips
- Do not tow a trailer du ring the break-i n pe ri­
od of your vehicle.
- If you tow a tr aile r, your A udi may requi re
more frequent ma intenance due to the ex­
tra load ¢
page 281.
Parking on a slope
Do not park on a slope with a trailer . If it cannot
be avoided, do so only after doing the following:
When parking:
.,. App ly the foot brake.
.,. Have someone p lace chocks unde r both the ve­
hicle and the trailer wheels .
.,. With chocks in place, slowly release the brakes
until the wheel chocks abso rb the load .
.,. Turn the whee ls towards the curb.
.,. App ly the parking brake .
.,. Select the P selector lever posit ion.

When restarting after parking:
"'Apply the foo t brake.
"' St art the engi ne .
"' Se lect the D selector leve r position.
"' Release the parking brake an d slow ly pull out
and away from t he wheel choc ks .
"' Stop and have someone retrieve t he wheel
chocks .
(D Tips
If you move the selector lever of the a utomat­
ic transm ission to P before applying t he park­
ing brake and before block ing t he wheels, you
may have to use mo re force late r to move t he
lev er out of th e P position .
Trailer mode
205

& WARNING
-Only wash the vehicle when the ignition is
off and follow the instructions from the car
wash operator to reduce the risk of acci­
dents.
- 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 . The brakes
must be dried first with a few careful brake
applications.
{[) 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.
Power folding exterior mirrors* must only
be folded in and out using the power folding
function.
- To prevent paint damage, do not wash the
vehicle in direct sunlight.
-
Care and cleaning
-To reduce the risk of damage to the surface,
do not use insect removing sponges, kitchen
sponges or similar items.
- 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 car wash cycles that apply pro­
tective wax. It can destroy the matte fin­
ish effect.
- Do not place any stickers or magnetic
signs on vehicle parts painted with matte
finish paint. The paint could be damaged
when the stickers or magnets are re­
moved .
@ 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 table. The in­
formation contained there is simply recommen­
dations. For questions or for components that are not
listed, refer to an authorized Audi dealer
or a qualified workshop. Also follow the informa­
tion found in
~ ,&. .
Cleaning exterior
Component Situation Solution
Wiper blades
Dirty ~ page 55, Cleaning windshield wiper blades
Headlights/ Dirty Soft sponge with a mild soap solution a>
tail lights
Sensors/
Dirty 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
Wheels Road salt Water
Brake dust Acid-free special cleaning solution
Exhaust tail Road salt
Water, cleaning solution suitable for stainless steel, if nee-
pipes essary
207

Checking and Filling
Checking and Filling
Hood
Releasing the engine hood
The engine hood is released from inside the vehi­
cle .
Fig. 194 Driver footwell : release leve r
Fig. 195 Ro cker switc h under the hood
Make sure the wiper arms are not raised up from
the windshield . Otherwise the paint could be
damaged .
.. With the driver's door open, pu ll the lever un ­
der the instrument panel in the direction of the
arrow ¢
fig. 194.
.. Raise the hood slightly Q _A .
.. Press the rocker switch under the hood upward
Q fig. 195. This releases the catch.
.. Open the hood.
A WARNING
Hot engine coo lant can burn you .
- To reduce the risk of be ing burned, never
open the hood if you see or hear steam or
coolant escaping from the eng ine compart­
ment. Wait unt il no steam or coolant can be
220
seen or heard before carefully open ing the
hood.
Working in the engine compartment
Be especially careful whenever you work in the
engine comportment.
Whenev er yo u mu st perform an y work in the
engin e compartment , for exampl e chec king and
filli ng d iffe rent fl uids , the re is a ri sk of injur y,
bu rn s and accid ent s. T o preven t perso na l injur y
alway s obse rve the foll owing WARNING S. The
en gine compartment o f an y v ehicl e is a haz ard ­
ou s a rea
Q _6 .
A WARNING
To help avoid injury, before you check any­
thing under the hood:
- Turn off the engine .
- Switch off the ignit ion.
- Apply the parking brake.
- Move selector lever to "P" (Park).
-Always let the eng ine cool down. Hot com-
ponents will burn skin on contact .
-
-To redu ce the risk of being burned, never
open the hood if you see or hear steam or
coo lant escaping from the engine compart­
ment . Wait until no steam or coolant can be
seen or heard before carefully opening the
hood.
- Keep children away from the engine com­
partment .
- Never sp ill fluids on hot engine compo­
nents. They can cause a fire.
- Never touch the radiator fan. The auxiliary
electric fan is temperature controlled and
can switch on suddenly.
- Never open the coolant reservoir cap when
the engine is sti ll warm. The coolant system
is pressurized and hot coolant could spray
out.
- Protect your face, hands and arm from
steam or hot engine coolant by placing a
thick rag over the cap when you open the
coolant reservoir .