2014 AUDI A8 brakes

98 Audi adaptive cruise control and braking guard
Driv ing in stop-and-go traff ic
A pplies to vehicles: with Audi adaptive cruise control
The adaptive cruise co ntro l system a lso as­
sis ts you in stop- and -go traff ic. If a previo us
detec ted veh icle ahead s tops, yo ur vehicle will
brake to a stop, within the limits o f the sys ­
tem .
,,. To res ume dr iv ing wi th adap tive cruise con­
t ro l, tap the accelerator pe dal or
,,. Pull the lever toward yo u into posit ion @
¢page 98 , fig. 100.
@ Tips
-If ada ptive cruise con trol is a ctive an d
you r vehicle does not start driving as ex­
pected after pulling the lever once, you
can start out aga in by tapp ing the accel­
erato r pedal.
- If an obstacle is detected when yo ur ve­
h icle starts dr iv ing, the system w ill
prompt you to take over
¢ page 99.
Your veh icle w ill drive more s low ly when
star ting . This may a lso happe n in some
s ituation s whe n no obstacle is apparent.
Interrupting cruise control
Applies to vehicles: with Audi adaptive cruise co ntrol
Fi g. 100 Selecto r lever
Requ irement : adaptive cruise control must be
sw itched on .
Overriding crui se control
,,. To accelerate ma nually, pull the lever to­
ward you into position @and hold it there .
The message
ACC override appears . Or
,,. press th e accelerator peda l. ,,.
To resume cruise cont ro l, re lease the lever
or take your foot off the accelerato r pedal.
Canceling cruise control while driving
,,. Move the lever in to posi tion @. T he mes­
sa ge
ACC standby ap pears. Or
,,. press the brake pedal.
,,. To resume the stored speed, move the lever
into position @.
Canceling cruise control when stopped
,,. Push the lever away from you i nto posit io n
@ . Th e message
ACC standby appe ars.
,,. To resume cruise contro l, press the brake
pedal an d pu ll the lever toward you into po­
sition @.
A WARNING
• -
Never resume the stored speed if the
sp eed is too high for p revailing r oad, traf­
f ic or weat her condit io ns.
Setting the distance
App lies to vehicles: wit h Audi ada ptive c ruise contro l
Fig. 101 Selector lever: setting t he dista nce
,,. Tap the switch to display the current set dis­
tance
r::!> fig. 101 .
,,. To increase or reduce the d istance by incre­
ments, tap the switch again to the left or
r ight. The d istance between the two vehicles
w ill change in the instrument cluste r dis­
p lay .
When approach ing a mov ing vehicle up ahead,
the adaptive cruise control system automati­ ca lly brakes to match that object's speed and
Ill>

100 Audi adaptive cruise control and braking guard
Audi braking guard
Descript ion
Applies to vehicles: with Audi adaptive cruise control
Fig . 10 3 Instrumen t cl uste r: approach warn ing
Braking guard uses radar sensors and a video
camera . It also functions within the lim its of
the system when adapt ive cruise control is
switched off .
What can braking guard do?
When detected in time, the system can assess
situations when a vehicle ahead brakes sud­
denly or if your own veh icle is traveling at a
h igh speed and approachi ng a veh icle up
ahead that is moving more slowly . Bra king
g ua rd does not react if it can not detect th e
situa tio n.
The system advises you of various situations:
- The
distance warning is given if you are too
close to the vehicle ahead for a long time. If
the vehicle ahead brakes sharply, you will not be able to
avoid a coll is io n. The indicator
li ght
I in the display comes on .
- The
approach warning is g iven when a de ­
tected veh icle up ahead in your lane is
mov ­
ing much more slowly than you are o r if it
brakes sha rply . W he n this wa rning is giv en,
it may only be poss ible to avoid a collisio n
b y swervin g or br aki ng sh arply . Th e ind ic ator
li gh t
I and indica to r i n the disp lay wi ll warn
yo u about t he danger ~
fig. 103. Yo u will a l­
so hear an acoustic signa l.
If yo u do not re act fa st enoug h or do not re act
at all to the si tuatio n, br aking gu ard will inte r-
ll Thi s is not ava ilable in some co un tri es .
vene by braking and the message braking
guard intervention
wi ll appea r.
- If a coll is ion is imm inent, the sy stem wi ll
fi rs t provide an
acute warning by br iefly and
sharply a pplying the brakes.
- If you do no t re act to the acu te w arning,
bra king g uard can brake w it h increas ing
force w it h in the lim its of the system . This
red uces the vehicle speed in the event of a
co llision.
- The system can initiate maximum b ra ki ng
short ly before a co llision
ll. Full dece leration
at high speeds occurs only in vehicles with
ada ptive cr uise control a nd side assist (pre
sense plus) .
- If the brak ing guard senses that yo u are not
brak ing hard en ough w hen a co llis ion is im­
m inent, it can increase t he b rak ing fo rce .
- The pre sense f unctions also engage whe n a
col lision is imm inent
c> page 197.
Which function s can be controlled?
You can switch braking guard and the dis­
tance/approach warning on or off in the M MI
c> page 101, Settings in the MMI.
A WARNING
-
Lack of attentio n can cause collisions, oth-
er accidents and serio us pe rsonal i nju ries.
Th e braking gua rd is an assist system and
c an not preve nt a collision by it self. T he
d rive r m ust always in tervene. The dr ive r is
a lway s respon sib le f or br aki ng at the cor­
r e ct t ime.
- Always p ay clos e atte ntio n to traffic,
even when the braking guar d is swi tched
on. Be ready to in te rvene and be re ady to
take c omp lete contro l whenever necessa­
ry. Always keep the safe and legal dis­
tance between your ve hicle and veh icles
up ahead.
- Bra king guard works within limits and
w ill not respond outside the system lim­
its, for examp le w hen approachi ng a
stopped vehicle or stationary obstacle ..,.

prevent the vehicle from "creeping", you
must keep your foot on the brake in all
selector lever positions except P and N
when the eng ine is running . Do not inad­
vertently press the accelerator pedal
when the veh icle is stationary . Otherwise
the vehi cle will s tart to move immediate­
ly, even if the park ing brake is set. This
cou ld result in a crash.
- Do not ride the brakes or p ress the brake
peda l too often or too long when dr iv ing
down a hill. Constant braking causes the
brakes to overheat and substant ially re­
duces b raking performance, increases
braking distance or ca uses comp lete fail­
ure of the brake system.
Hill descent control
The hill descent control system assists the
driver when driving down declines.
H ill descent control is activated when these­
lector lever is in D/S and you press the brake
pedal. The transmission automatically se lects
a gear that is suitab le for the incline . Hill de­
scent control tries to maintain the speed ach­ ieved at the time of brak ing, within physical
a nd techn ical limitations.
It may st ill be nec­
essary to adjust the speed with the brakes.
H ill descent control switches off once the de­
cline levels out or you press the accelerator
pedal.
Hill descent control is also activated when the
speed is set by starting the cru ise contro l sys­
tem
r:::;, page 91.
A WARNING
H ill descent control can not overcome
phys ical limitations, so it may not be able
to main tain a constant speed under a ll
condi tions. Always be re ady to app ly the
br akes.
Automatic Tra nsmi ssi on 119
Shifting manually
The shift paddles allow the driver to shift the
gears manually .
Fig . 12 5 Steer ing w hee l: s hifting manually
.,.. To shift to a h igher or lowe r gear tempo rari­
ly, tap the
0 or 0 shift paddler:::;, fig. 125 .
.. To switch manua l mode on, press the~
button . An Mand the gear that is currently
engaged appear in the inst rument cluster
disp lay @ ¢
page 116, fig. 122.
.. To shift up one gear, tap the righ t shift pad­
dle
0 r:::;, fig . 125 .
.. To sh ift down one gear, tap the left shift
paddle Q.
.. To switc h manua l mode off, press the~
button aga in, or
.. Move the selector lever back and release it .
T he transm iss ion automatically sh ifts up or
down before cr itical engine speed is reached.
The transm iss ion only allows manual sh ifting
whe n the eng ine speed is w ith in the pe rmit­
ted range .
The eng ine braking effect increases when you
downshift when going downhill .
Kick-down
Kick-down enables maximum acceleration .
When you press the accelerator pedal down
beyond the resistance point, the automatic
transmission downsh ifts into a lower gear, de­
pending on veh icle speed and eng ine RPM .
It
shifts up into the next higher gear once the
maximum specified engine RPM is reached . ..,.

200 Intellig ent technol ogy
ESC includes and/or works together with the
anti-lock braking system (ABS), brake assist
system, anti-slip regulat ion (ASR), electronic
d ifferential lock (EDL), dynamic steering* and
electronic interaxle differential lock*. ESC is
switched on all the time. In certain situations
when you need less tract ion, you ca n sw itch
off ASR by pressing the button above
~ page 201, fig. 188 the se lector lever. Be
sure to sw itch ASR on aga in when you no lon­
ger need less traction.
Anti -lock braking system (ABS )
ABS prevents the wheels from locking up
when braking. The vehicle can still be steered
even du ring ha rd b raking . Apply steady pres­
sure to the brake pedal. Do not pump the ped­
a l. A pulsing in the brake peda l indicates that
the system is he lping you to brake the vehicle.
Br ake assist system
The brake assist system can decrease brak ing
d istance. It increases braking power when the
d river p resses the brake pedal q uick ly in emer­
gency situations. You must press and hold the brake peda l until the situation is over. In
vehicles with adaptive cruise control*, the brake assist system is more sensitive if the
d istance detected to the vehicle ahead is too
small.
Anti- slip regulati on (ASR )
ASR reduces engine power when the drive
wheels begin to spin and adapts the force to
the road condit ions. This makes it easier to
start, accelerate and drive up hills.
El ectronic diff erential lo ck (EDL )
The ED L brakes wheels that are spinning and
transfers the drive power to the other drive
wheel or whee ls if the vehicle is equipped with
all whee l drive*. This funct ion is available up
to about 7S mph (120 km/h).
In extreme cases, EDL a utomatica lly switches
off to help keep the brake on the braked whee l
from overheating. EDL will switch on again au­
tomatically when conditions have returned to normal.
Dynamic ste ering *
On vehicles with dynamic s teering, ES C helps
stabilize the steering in certain situations.
Electronic interaxle differential lock
function*
T he electronic interaxle differentia l lock f unc­
tion activates when driving thro ugh curves.
Braking is targeted toward the wheels on the
inside of the curve as needed . This he lps to
minimize front whee l skid, improves traction
and allows for more precise driving through
curves .
A WARNING
- ESC, ABS, ASR, EDL, dynamic steering*
and the electronic interaxle differential loc k function* cannot overcome the laws
of physics. This is espec ially impo rtant
on slippery o r we t roads.
If the systems
begin acting to stabilize your vehicle, you
should immediately change yo ur speed
to match the road and traffic conditions .
Do not let the increased safety provided
by these systems tempt you to take risks. Doing so will increase the risk of a loss of
veh icle control, collision and ser ious per­
sonal injur ies.
-Always adapt your speed to road, traffic and weather conditions. The risk of los­ing control of the vehicle increases when
d riving too fast, espec ially through
curves and on slippery or wet roads, and
when driving too close to vehicles up
ahead. ESC, ABS, the brake ass ist sys ­
tem, EDL, ASR, dynamic steering * and
the electron ic interaxle differential lock
function* cannot prevent collisions.
- Always accelerate with special care on
even, smooth s urfaces such as those that
are wet or covered with ice and snow.
The drive wheels can spin even w ith
these assistance systems that cannot al­
ways he lp to red uce the risk of loss of ve­
h icle control.
-

202 Intellig ent technol ogy
to have your brake pads inspected can result
in reduced brake performance.
On steep slopes, yo u shou ld use the b rak ing
effect of the engine. Th is way, you prevent un­
necessary wear on the brake system. If you
must use your brakes, do not hold the brakes
down continuously. P ump the brakes at inter ­
vals.
Operating nois e
Noises may occur when braking depending on
the speed, braking force and outside condi­
tions such as temperature and humidity.
E ff ect of water and road salt
In certain situat ions, for example after driving
through water , in heavy ra in , after overn ight
condensation or after washing your car, the braking effect can be reduced by moisture or
ice on the brake rotors and brake pads. The
brakes must be dried first with a few careful
brake applications.
At higher speeds and with the windshield wip­
ers turned on, the brake pads press against
the brake rotors for a short amount of time.
This occurs at regular intervals without the
driver noticing and provides for bet ter brake
response time under wet condit ions .
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 . Likew ise,
you clean off accumulated salt coating from
brake discs and pads with a few caut ious ap­
plications of the brake
9 .&, .
Cor ro sion
There may be a tendency for dirt to build up
on the brake pads and corrosion to form on
the discs if the car is not dr iven regularly or
only for short t rips with little use of the
b rakes .
If the brakes are not used frequently , or if cor­
rosion has formed on the discs, it is advisable
to clean off the pads and discs by braking
firm ly a few times from a mode rately high
speed
9 .&, .
Faults in the brake syste m
If you shou ld notice a sudden increase in
brake pedal trave l, then one of the two brake
circuits may have fai led
9 & .
Low bra ke fluid lev el
Malfunctions can occu r in the bra ke system if
the b rake fluid level is too low. The brake flu id
level is monitored electro nica lly.
Brake lining we ar statu s
Brake lining wear may be checked by visual in­
spect ion of the condition of the brake pads
th rough the open ings in the wheel. If neces ­
sary, the wheel may be removed for t his i n­
spect ion
9 page 2 72, Changing a wheel.
A WARNING
- You shou ld perform braking maneuvers
for the purpose of cleaning the brake system only if road conditions permit.
Other road users must not be put at risk -
you may cause an accident!
- Before descending a steep grade, reduce
speed and sh ift transmission into a lower
gear or lower dr iving range. Do not ride
the brakes or hold the pedal down too
long or too often . This could cause the
b rakes to get hot and diminish braking
efficiency.
- Do not "ride the brakes" by rest ing your
foo t on the pedal when you do not intend
to brake. This may cause the brakes to
overheat, premature wear and increased
stopping distance.
- Unde r certain cl imatic and operat ing
conditions such as passing thro ugh wa ­
ter, driving in heavy rain or after washing
the vehicle, the effectiveness of the brakes can be reduced. In winter, ice can
accumu late on the brake pads, linings,
d iscs and drums. Carefully app ly brakes
for a test. Brakes will dry and ice coat­ ings will be cleaned off after a few care­
fu l brake applicat ions.
- Driving for an extended period of t ime on
salt-covered roads without using your brakes can a lso affect bra king efficiency.
~

Clean off accumulated salt coating from
brake discs and pads with a few careful
brake applicat ions .
-If you damage the front spoiler, or if you
install a different spoiler, be sure the air
flow to the front brakes is not obstruct­ ed . Otherwise the brake system could
overheat reducing the effectiveness of
the ent ire brake system.
- Failure of one brake c ircuit will impair
the braking capability resulting in an in­
cr eased stopp ing distance. Avoid driv ing
the vehicle and have it towed to the near­ est Aud i dea ler or q ualified wor kshop .
- Never let the vehicle rol l to a stop w ith
t he engine shu t off.
- If the brake booster is not work ing, the
brake pedal must be pressed conside ra­
bly harder to make up for the lac k of
booster assistance.
Brake booster
The brake booster adds extra braking power.
The brake booster works w ith vacuum pres ­
sure which is created only when the engine is
ru nning
9 ,&. .
,&. WARNING
-Never le t the vehicle ro ll to a stop w ith
t he engine shu t off.
- If the brake booster is not work ing, fo r
ex ample when towing your ve hicl e, or
because the b rake booste r has somehow
been damaged, the brake pedal must be
pressed considerab ly harder to make up
for the lack of booster assistance.
Servotronic - advanced
power steering system
-
The power steering systems use the power of
the running engine to allow precise steering
with little effort.
The advanced Servotronic power steering sys­
tem senses the road speed and electron ically
ad ju sts powe r ass istance to provide comfor ta-
Int ellig ent technolog y 203
ble and safe steering response exactly match ­
ed to th e vehicle speed .
Power steer ing will not work if the engine is
off . As a result, the steering wheel will be h ard
to tu rn.
T he powe r stee ring fluid level is checked d ur­
i ng t he sched uled maintena nce services.
(D Note
If there is an e lectronic malfunction, ser­
votronic
will s till fu nction like a conven­
tiona l powe r steering system, providing a
constant steering s upport force tha t is no
l onge r proportionate to the vehicle speed.
This is most noticeab le when t urni ng the
steering wheel at low speeds (for example
when parking), -more effort w ill be re­
quired than usual.
- Be aware of the different than usual steering response and adjust your steer­
ing force accordingly.
- Have the problem checked and set right by an Audi dealer as soon as possible.
(D Tips
-When the engine is running, never hold
the steering wheel turned all the way to
the right or to the left for longer than 15
seconds . The power steering pump will
overheat the hydraulic fluid if yo u keep
holding the stee ring wheel turned all the
way. This is likely to damage the power
steering sys tem.
- If the powe r stee ring system should fa il
entire ly, o r if t he engine is not runn ing
(for example, wh ile be ing towed), you
w ill still be able to steer the veh icle .
However,
considerably more effort will
be required to do so .
- If the powe r steering system sho uld
have a leak, or is not functioning proper­
ly, contact your author ized Audi dealer
immediately.
- The power steering system req uires a
specially formu lated hydraulic fluid. The
power steering fluid reservoir is located
in the engine compartment
9 page 233. IJJ,,
•
•

Driving and
environment
The first 1
1000
miles
(11500 km) and
afterwards
New engine
The engine needs to be run-in during the first
1,000 miles (1 ,500 km) .
For the first 600 mile s (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 engine speeds .
From 600 to 1,000 mile s (1 ,000 to
1,500 kilometers):
.. Speeds can gradually be increased to the
maximum pe rm iss ib le road or eng ine speed .
During and after break-in per iod
.,. Do not rev the engine up to high speeds
when it is cold. This applies whether the
transmission is i n N (Neutra l) or in gear.
After the break- in peri od
.. Do not exceed maximum engine speed un­
der any circumstances.
.,. Upshift into the next higher gear
before
reaching the red area at the end of the tach­
ometer scale
¢page 10.
During the first few hours of driving, the en­
g ine's interna l friction is higher than later
when all the moving parts have been broken
i n. How well this break-in p rocess is done de­
pends to a considerable extent on the way the
ve hicl e is driven du ring the first 1,000 miles
(1,500 ki lome ters).
(D Note
Extremely h igh engine speeds are auto­
mat ica lly reduced. However, t hese rpm
lim its are progr amme d for an eng ine well
r u n- in, not a new engine .
Driving and environment 207
@) For the sake of the environment
Do not drive with unnecessarily high en­
g ine speeds -upshifting ear ly saves f uel,
reduces noise and protects the environ­
ment.
New tires
If your vehicle is running on new tires, drive
particularly caref ul for the first 350 miles
(500 kilomete rs) afte r fitt ing.
.&, WARNING
N ew tires tend to be sl ippery and mus t al­
so be "b roken -in" . Be sure to remember
this dur ing the f irst 350 m iles (500 kilo­
meters) . Brake gently . Avoid fo llowing
closely behind other vehicles or other sit­
uations that m ight require sudden, hard
b raking .
New brake pads
Remember that new brake pads do not have a
full brak ing effect dur ing the first 250 m iles
(400 ki lomete rs) afte r they are installed.
New brake pads have to be "broken in" before
they have optima l grab ¢,&. .
D uring the brea k-in period, yo u should avo id
putting severe loads on the brakes. Severe
l oads include , for example, sudden hard brak­
i ng, in particular at very h igh speeds or, for
example, on mounta in passes .
.&, WARNING
New b rake pads don't have the best stop­
p ing power and must be "broken-i n" dur­
ing the initi al 100 to 150 miles (150 to
2 00 kilometers) o f no rma l ci ty driving . You
can compensate for this by pressing the b rake peda l more fi rm ly . This also applies
later when new pads are installed.
•
•

A WARNING ,~
- Do not park your vehicle over flammable
materials such as grass or leaves because
the high temperature of the diesel par­
t icu late filter cou ld start a fire .
- Do not apply an underbody protectant in the exhaust system area or a fire could start .
Shutting down vehicle
If you would like your veh icle to remain inop ­
erat ive for a longer period of time, contact an
Aud i or other specia lized dealer. They can ad­
vise you on necessary precautions e.g . corro­
sion prevention, ma intenance and storage.
Pay attention to additiona l information con­
cerning the battery. Refer to~
page 243.
Avoid damaging the
vehicle
When you a re driving on poor roads, or over
curbs, steep ramps, etc., make certain that low-lying parts such as spoilers and exhaust
system parts do not bottom out and get dam­
aged.
This is especially true for vehicles with low­
slung chassis (sports chassis)* and fully load ­
ed vehicles.
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
bottom of the veh icle 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
-
Drivin g and environment 209
the brakes first by braking carefully to re­
store the full braking effect.
(D Note
- Vehicle components such as the engine,
transmission, suspension or electrical
system can be severely damaged by driv­
ing through water.
- Always switch off the Start-Stop-System
when driving through water~
page 88.
(D Tips
-Check the depth of the water before driv­
ing through it .
- Do not stop the vehicle, drive in reverse
or switch the engine off when driving
through water.
- Keep in mind that oncoming vehicles may create waves that raise the water
level and make it too deep for your vehi­
cle to drive through safely .
- Avoid driving through salt water because
it can cause corrosion.
Operate your vehicle
economically and minimize pollution
General
Your personal style of driving will determine
t he economy of your vehicle , as well as ex­
haus t and noise levels.
Fuel economy, environmental impact, and
wear on your engine, brakes and tires largely
depend on three factors:
- your personal driving style
- operating conditions
- technical limitations
If you ant icipate what you need to do next and
drive econom ically, you can easily cut your
fuel consumpt ion by 10-15 percent . Th is sec­
tion w ill give you some tips on how you can
help the env ironment and your pocketbook. •
•