wheel AUDI S8 2010 Service Manual

lillill.a._...:I:..: n~ t .::.e::::..::.: ll~igent technology ,_ _______________________________________ _
Brake booster
The brake booster adds extra braking power.
The brake booster works with vacuum pressure which is created on ly
w hen the eng ine is ru nn ing =>& .
& WARNING
• Nev er let the vehicle roll to a stop w ith the engine shut off.
• If the brake booster is n ot working , for e xample when towing
your vehicle, or because the brake booster has som ehow been
damaged , the brake pedal must be pressed conside rably harder to
make up for the lack of booster assistan ce. •
Functioning of Anti-Lock Brake System
(ABS)
A BS prevents the wheels fr om locking up under braking.
The ABS co ntributes effectively to ve hicle contro l s i nee it preve nts the
w heels from
locking when the brakes a re applied. T his means that the
vehicle remains steerable and is less likely to skid .
With ABS you do not need to pump the brake. Just hold the brake
pedal down.
However, do not expect the A BS to shorten brak ing distance under all
circumstances. When driving on grave l o r on newly fa llen snow on top
of icy su rfaces, b raking distance may be even longer, therefore, under
these circumstances, it is especially important that you drive slowly
and w ith great care.
How the ABS system works
An automatic check is made w hen a speed of abo ut 4 mph (6 km/h) is
reached . When this happens, a pumping noise can be heard . If a
n ind iv idua l wheel begins to rotate too slow ly in relat ion to ve hicle
speed and tends to lo ck, the ABS automat ically redu ces bra ke pres ­
su re to p revent t hat wheel from lock ing.
Th is automatic adjustment process wi ll cause a
slight vib ration of
t he bra ke pedal and so me noises to al er t you tha t vehicle s peed mus t
be adapted to existing road and traff ic conditions.
& WARNING
Although the ABS is very effective, always remember that braking
capability is limited by tir e traction. Always adjust your driving
speed acco rding to the road and traffic conditions. Do not let the
extra safety afforded by the ABS tempt you into taking extra ri sks .
The ABS cannot ove rcome the laws of physics.
[I) Tips
• If ABS is not funct ioning properly, a warning light will come on.
See=>
page 19.
• If a fa ult occ urs in the ABS, the ED L is also not functioning . This is
ind icated by the A BS warn ing ligh t.•
Brake assistant
T he brake assistant is designed to achi eve the optimum
b ra king effect.
The b rake ass istant helps to i ncrease the effective brak ing power and
thus to achieve a shorter stopping distance. If the driver p resses the
bra ke pedal
very quickly, the brake assistan t automatically boosts t he
brak ing fo rce to the maximum level, up to the po int where the anti­
lo ck bra ke f un ct ion (ABS) intervenes to stop the whee ls from locking.
You shou ld then keep the brake pedal pressed unt il the ve hicle has
bra ked to t he required s peed . T he bra ke ass ist ant sw itches itse lf off
as soon as you re lease the brake pedal. ._

_________________________________________ I_ n_ t_ e_ ll_,igent technology ,__E~-
The brake assistant will not be operative if there is a malfunct io n in
t he ABS.
& WARNING
Plea se remember that the accident ri sk a lwa ys increa se s if you
d riv e too fast , especially in corne rs or on a slippery road , or if you
follow the vehi cle ahead of you too closely . In cre ased ri sk of an
accident cannot be compensated for e ven by the brake ass istant,
so always maintain a safe speed. •
Servotronic® - advanced power
steering system
The power steering systems uses th e power of the
running engine to allow precise steering with little effort.
Th e advanced Servotronic ® power steeri ng system senses the road
speed and electronically ad justs power assistance to provide
c omfortable and safe s teer ing response exa ctly matched to the
vehicle speed.
Powe r steering will not work if the engi ne is of f. As a resu lt, the
steer ing wheel will be hard to turn .
The power stee ring fluid level is checked during the sched uled main­
t enance se rvi ces.
0 Note
If the re is an ele ct roni c mal func tion, servotroni c will still f unction
like a conventional power steer ing system, prov iding a constant
steeri ng support force tha t is no lo nger propo rt iona te to the ve hicle
speed. This is most not iceab le when turn ing the steer ing wheel at low
speeds (for example when parking), -more effort will be required
than usual.
Controls and equip­ ment Safety first Vehicle operation
•
Be aware of the d ifferent than usual steering response and adjust
your stee rin g for ce acco rdi ng ly.
• Have the prob lem checked and set r ight by an A udi dea ler as soon
as possib le.
[ i ] Tips
• Whe n the eng ine is runni ng, neve r hold t he steering w hee l turned
all the way to the right or to t he left for longer than 15 seconds. The
powe r stee ring pump wi ll over heat the hydra ulic fluid if yo u keep
holding the steeri ng w heel tur ned all the way. This is likely to damage
the power steering system .
• If the power stee ring system shou ld fa il entire ly, or if the engine
is not r unning (fo r examp le, while being towed), you w ill still be a ble
to steer the vehicle. However,
considerably more effo rt will be
req uired to do so .
• If the power steering system s hou ld have a lea k, or is not func­
tioning properly, contact your authorized Au di dea ler immediate ly .
• The power steering system requ ires a specially formulated
hydra ulic fl uid. The power stee ring re se rvoir is t he one located mos t
forward o n the left side of the eng ine compa rtment=:>
page 290 . The
correct fluid leve l in the reservoir is important fo r proper f unctioning
of t he power steering. •
Dr"ving with your quattro®
With All Whee l Drive, all four wheels are driven .
General information
With All Wheel Drive, power is d istributed to all four wheels. This
happens au tom atically depending on you r d rivi ng style a nd the roa d
conditions at the time. See also=>
page 253, "Electronic different ial
lock (ED L)".
Vehicle care Do-it-yourself service Technical data

Intelligent technology
'-----------------------------------------------
W inter tires
When d riving in the winter, your vehicle with A ll Whee l Drive has an
advantage, even with reg ula r tir es . In wi nter road cond it ions i t may
be advisab le to mount w inte r tires (or all-season tires) for imp roved
dr iveabili ty and braking: these tires m ust be mounted on
all four
wheels .
See also => page 323, "Winter tires".
Tire chains
Whe re tire chains are mandato ry on certa in roads, this normally also
applies to veh icles with A ll Whee l Drive=>
page 324, "Snow chains ".
Replacing wheels/tires
Veh icles with All Wheel Drive m ust always have t ires of the same size.
Also avoid tires with different trea d de pths . For details see page
=>
page 318, " N ew tires and replac ing tires a nd wheels" .
Off-Road driving?
Your Audi does not have enough ground clearance to be used as a n
off -road vehi cle. It is the re fore best to avoid ro ug h trac ks and uneven
ter rain as muc h as poss ib le. Also re fer to=>
page 263 .
& WARNING
Always adjust your dri ving to road and traffic conditions. Do not
let the extra safety afforded by All Wheel Drive tempt you into
taking ex tra risks.
• Although the All Wheel Drive is very effective, always
remember that braking capacity is l imited by tire traction. You
should therefore not drive at exce ssive speeds on icy or slippery
road surfaces.
• On wet road surfa ce s, be careful not to drive too fast because
the front wheels could begin to slide on top of the water (aqua­
planing ). If this should occur, you will have no warning from a
sudden increase in engine speed as with a front-wheel drive
vehicle. Always drive at speeds which are suited to the road condi­
tions - risk of crash. •
Energy management
Starting ability is optimized
Energy m ana gemen t con tr ols the distributi on of elec­
trical ener gy an d thu s optimiz es the ava ila bility of elec­
t ri cal ene rgy f or starting the en gine.
If a vehicle w ith a convent iona l energy system is not driven for a long
pe riod of time, t he b att ery is di sch arged by idling current con sumers
(e .g. immob ilize r). In certain c ircumstances it can result i n there
be ing insuffi cien t energy avai lab le to s tar t the engine.
I n te lligent e ne rgy management in yo ur vehicle ha ndles the dist ribu­
tion of e lectrical energy . Starting ab ility is ma rkedly improved and
t he life of the battery is extended.
Basically, energy management consists of
battery diagnosis , idling
current management
a nd dynamic energy management .
Battery diagnosis
Batte ry diagnosis co nti nu ously deter mi nes the s tate of the batte ry .
Sensors determine battery vo ltage, battery current and battery
t empe rature. This determines the cur rent sta te of charge and the
power of the battery.
Idling current management
Id ling current management red uces energy consumpt ion while the
veh icle is s tanding. W it h t he ignition swi tched off, it con trol s the
energy supply to the var ious electrica l components. Data from
b attery di ag nos is is conside red .
Depe nding on the batte ry 's state of charge, individ ua l consumers a re
gradually t urne d off to prevent excessive discha rge of the batte ry an d
t hus main tain sta rting capabili ty .
Dynamic energy management
W hile the vehicle is being driven, dynamic energy management
dis trib utes the energy generated acco rding to the nee ds o f the indi -•

Trailer towing
"---------------------------------------------------
Speed
T he higher the speed, the more difficult it becomes for the driver to
control the rig. Do not dr ive at the max imum permiss ible speed.
Reduce your speed even more if load, weather or wind conditions are
unfavorable -part icu larly when go ing downhill.
Reduce vehicle speed
immediately if the tra iler shows the slightest
sign of swaying.
Do not try to stop the swaying by accelerating.
Observe speed limits. In some areas, speeds for veh icles towing
trailers are lower than for regu lar vehicles.
Always apply brakes early. When driv ing dow nhill, shift in to a lower
gear to use the eng ine braking effect to slow the veh icle. Use of the
bra kes alone can cause them to overheat and fail.
Coolant temperature
Th e coolant temperature gauge~ page 10 must be observed care­
fully. If the needle moves close to the upper end of the scale, reduce
speed immediately and/or turn off the air conditioner.
If the coolant temperature warning light in the instrument cluster
starts flashing
_f_ , pull off the road, stop and let the engine idle for
about two m inutes to prevent heat build-up.
& WARNING
Anyone not properly restrained in a moving vehicle is at a much
greater risk in an accident. Never let anyone ride in your car who is
not properly wearing the restraints provided by Audi.•
Trailer towing tips
Important to know
------------
Your vehicle handles differently when tow ing a trailer because of the
additiona l weight and different weight distribution. Safety, perfor- mance and economy will greatly depend on how carefully you load
your trailer and operate your rig.
Before you actually tow your trailer, practice turning, stopp ing and
backing up in an area away from traffic. Keep practicing until you have
become completely familiar with the way your vehicle-t railer comb i­
nation behaves and responds.
Backing up is difficult and requires practice. Backing up with a trailer
generally requires steering action oppos ite to that when backing up
your vehicle without a trai ler.
Maintain a greater distance between your 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 that you cannot accelerate as fast as you normally would because of the added load . Make sure you have
enoug h room to pass. After passing, allow plenty of room for your
trai ler before changing lanes again.
Avoid jerky sta rts, sharp tur ns or rapid lane changes.
W Tips
• Do not tow a trailer during the break-in per iod of your veh icle.
• If you tow a trai ler, your Audi may require more frequent mainte­
nance due to the extra load
~ page 361. •
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:
- Apply the foot brake.
- Have someone p lace chocks under both the vehicle and the
trailer wheels . ._

-With chocks in place, slowly release the brakes until the
wheel chocks absorb the load.
- Turn the whee ls towards the curb .
- Apply the parking brake.
- Move the selector lever to
P.
When restarting after parking:
- Apply the foot brake.
- Start the eng ine .
- M ove the selector lever to
D.
-Release the parking brake and slowly pu ll out and away
from the wheel chocks .
- Stop and have someone retrieve the wheel chocks .
[ i ) Tips
If you move the se lector lever of the automat ic t ransm ission to P
before applying the parking brake and before blocking the whee ls,
yo u may have to use mo re force later to move the leve r out of t he
P
position. •
Controls and equip­
ment Safety first Vehicle operation
Vehicle care Do-it-yourself service Technical data

-~_C_ le_ a_n_ i_ n_ g=- a_ n_d___. p_ ro_ t_e _c_ t_ i_o _n ___________________________________________ _
Cleaning and protection
General information
Regular care preserves vehicl e val ue.
Any automobile is exposed to industria l fumes, co rrosive road salt,
m ud dy dog fee t, e tc. A well c ared for Audi can look like new many
years after p urchase . Regular and correct care will contribute to
m aint aining the bea uty and val ue of your Audi.
Furthermore, good care may be a condition for substantiating a
warranty claim should corrosion damage or paint defects occur.
Y ou r au thor ized Audi d eale r h as a var iety of dedicated vehicle-care
products
and can advise w hich ones to use for clea ning the exterior
a n d inter io r of your ve hicle.
W het her you use products recommended by Aud i or o ther comme r­
cia lly availab le cleaning agents , please ma ke sure yo u appl y them
co rrectly .
& WARNING
• Cleaning agents may be poisonous . Keep them out of the reach
of children.
• Heed all caution labels .
• Always read directions on the container before using any
product. Follow the directions carefully.
• Most chemical cleaners are concentrated and have to be
diluted .
• Use spot removing fluids only in well ventilated areas.
• Do not use gasoline, kero sene , diesel fuel , nail polish remover
or other volatile fluids . They may be toxic, flammable or
hazardous in other ways. Do not wash, wax or dry the vehicle with
the ignition on or the engine running.
& WARNING (co ntinued)
• Do not clean the under sides of chassi s, fenders , wheel covers,
etc. without protecting your hands and arms. You may cut your­
self on sharp-edged metal parts.
• Moisture and ice on brakes may impair braking efficiency
~ page 254, "General information ". Test the brakes carefully
each time you wash the vehicle .
'£> For the sake of the environment
Select only envir onmenta lly fr iendly clea ning produc ts . Leftover
cleaning pro ducts sho uld not dis posed of i n the household waste .•
Care of exterior
Washing
F re qu ent w ashin g protec ts th e vehicl e.
T he best protection aga inst env ironmental influences is frequent
w ashi ng and w ax ing. How o ften t his is requ ired depen ds on:
• How m uch the vehicle is use d
• Whe re the ve hicle is parke d (gar age, in the o pen un der tr ees, e tc.)
• The seasona l and weather conditions
• E nviron mental influences
T he longer bi rd droppings , insects , tree resin, road and industria l
gr ime, t ar, soo t, road sa lt and o ther ma ter ia ls remain on the veh icle
body, the more lasti ng their destructive effects w ill be. H igh temper­
atu res cause d by ex pos ure to intense s unlight int ensify the co rrosive
effect, part icu larly when humid ity is high as we ll.
~

Cleaning and protection -
---------------=---------=----
Under certain circumstances, weekly washing may be necessary.
Under other conditions, a monthly washing and waxing may be
adequate.
After the winter, the underside of the vehicle shou ld be thoroughly
washed, p referably in a profess ional car wash.
& WARNING
Always read and heed all WARNINGS and other information
~page 270. •
Automatic car wash
The vehicle can be washed in almost any modern auto­
matic car wash.
Th e vehicle paint is so durable that the vehicle can normally be
washed without problems in an automatic car wash . However, the
effect on the paint depends to a lar ge exten t on the design of the
facility, the filtering of the wash water, the type of wash and care material, etc. If the paint has a dull appearance after going through
the car wash or is scratched, bring this to the attention of the oper­
ator immediately . If necessary, use a different car wash.
Before going thro ugh a car wash, be sure to take the usual precau­
tions such as closing the windows and power roof. Factory installed
antennas must not be removed.
If you have installed additional accessories on the vehicle -such as
spoilers, roof rack, etc. - it is best to ask the car wash operator if these
should be removed.
& WARNING
Always read and heed all WARNINGS and other information
~page 270. •
Safety first
Washing the vehicle by hand
A lot of water is needed when washing a vehicle by hand.
-Before you star t washing, make sure you have read and
understood the WARNINGS~
& in "General informa ­
tion" on
page 2 70.
- First soak all dried dirt until it is soft, then rinse it off .
- As you clean your vehicle, start with the roof and work your
way down to the bottom, using a sponge, a sponge glove
or a clean brush.
- Rinse the sponge or the sponge glove often, flush ing it
clean each time .
- Use special car shampoo only for very persistent dirt.
- Rinse the car thoroughly with water.
- Use a chamois leather to gently wipe the exterior dry.
Use a separate sponge for cleaning the wheels, door sills and other
regions exposed to road dirt. In this way, you will not scratch the
paint with coa rse particles imbedded in the sponge the next time you
wash the car.
& WARNING
• Do not clean the underside of the chassis, fenders, wheel
covers, or other hard to reach parts without protecting your hands
and arms. You may cut yourself on sharp-edged metal parts.
• Always read and heed all WARNINGS and other information
~page 270. _..
Vehicle care Technical data

Cleaning and protection Ill
---------------=---------=----
The best way to remove snow from w indows and mirrors is to use a
br ush . Use a non- abra sive
plastic ice scraper -better st ill, a spray
deicer -to remove
ice from w indows and mirro rs .
Oil, grease or s ilicone residue can be removed with
glass cleaner or
s ili cone remover . However, wax res idue requires the use of a spe cially
formulated solvent. Please contact your A udi dea ler for advice on safe
pro duc ts for w ax remov al.
W indows should also be cleaned on the inside at regu lar i ntervals .
N ever dry wi ndows w it h the same chamo is that you use to dry painted
s ur fa ces. Wax res idue on the chamois ca n impair vis ion t hrough t he
windows.
& WARNING
• Always read and heed all WARNINGS and other information
=> page 270 .
• The wind shield must not be treated with water-repellent
material s. They can in crease glare und er poor visibility conditions
such as wetness , darkness , or when the sun is low on the horizon .
In addit ion, they can cause the w indshield wipers to chatter.
0 Note
• N ever use warm o r hot water to remove snow and ice from
windows and mirrors . This cou ld cause the glass to crack .
• To prevent damage to the wires of the rear defogger, do not place
any a dhesive stickers on t he inside of the rea r window over the wires.
• To help prevent dirt from scratching the window, a lways scrape in
a forward direction -pushing the scrape r away from you -neve r back
and fort h.•
Safety first
Weatherstrips
Com plete car care includes the weat herstrips as well.
- Ap ply a sui tab le rubb er condi tion er to t he w eathers tri ps
f rom tim e to t ime .
To be able sea l prope rly, the weat hers tr ips arou nd the hood, doo rs,
rear lid, etc. must remain pliable. Spray the weathe rst rips with sili­
c one or coat them with tal cum powder o r g lyce rine to reta in the flex­
ibility of the rubber and to protect them against freezing in the
winter.
& WARNING
Alway s read and heed all WARNINGS and other information
=> page 2 70.
[I) Tips
Keep silicone sprays off the winds hie ld to avoid wiper smear in ra in. •
Cast (light) alloy wheels
Cast (light) all oy wheels requir e spe cial c are.
- Was h the whe els wi th a spo nge or h ose br ush ev er y ot her
w eek .
- Fo r deep cleaning afterwar ds, use on ly a dedi cated
acid­
free cas t all oy whee l cleaner.
- R ub a coat of
liquid wax onto the r ims eve ry three month .
Be su re to reac h and trea t all parts o f the rim.
To preserve the decorative appearance of the cast alloy whee ls , some
special care is necessa ry . In ad d it io n to road dirt and s alt , bra ke du st
is a lso corrosive . If left on for too long, brake dust can cause pitting . ..,_
Vehicle care Technical data

-~_C_ le_ a_n_ i_ n_ g=- a_ n_d___. p_ ro_ t_e _c_ t_ i_o _n ___________________________________________ _
in. WARNING
Be aware: The engine compartment of any motor vehicle is a
potentially hazardous area.
• Before working in the engine compartment, be sure to read the information =>
page 281.
• Before reaching into the front plenum panel, always remove
the ignition key . Otherwise, the windshield wiper system could
unintentionally be switched on, possibly causing personal injury
from the moving wiper linkage.
• Never reach into the area around or touch the radiator fan. The
auxiliary fan is temperature controlled and can switch on suddenly
- even when the ignition is off.
• Do not wash, wax or dry the engine with the engine running.
Moving or hot parts could injure you.
• Do not clean the underside of the chassis, fenders, wheel
covers, or other hard to reach parts without protecting your hands
and arms. You may cut yourself on sharp-edged metal parts.
• Always read and heed all WARNINGS and other information
=:> page 270. •

-~_T_ i_ re _ s_ a_n _ d_ w_ h _e_ e_ ls _________________________________________________ _
Tires and wheels
Tires
General notes
Tires may be the least appreciated and most abused
parts of a motor vehicle.
T ir es may be the least apprec iated and most abused pa rts of a moto r
vehicle. Tires are, however, one of the most important parts of a
veh icle, parti cularly conside ring the comparative ly small patch of
rubber on eac h tire that assu res that all- important co ntact between
you , your ve hicle and the road .
Ma inta in ing t he correct t ire pressu re, making s ure that your veh icle
and i ts tires do not have to carry more weight than they can safely
hand le, avoid ing damage from road ha za rds and reg ula rly inspect ing
tires for damage incl ud ing c uts, s lashes irregular wea r and overall
condi tion are the mos t important th ings that you can do to help avoi d
sudden tire fa ilure includ ing t read separation and blowouts .
Avoiding damage
If you have to drive over a curb or sim ilar obstacle, drive very s lowly
and as close as poss ible at a right angle to the cu rb .
Always keep chemicals including grease, oil , gasoline and bra ke fl uid
o ff the t ires .
Inspect the ti res regularly for damage (cuts, crac ks o r bl ist ers, e tc .).
Remove any foreign bodies embed ded in the trea ds.
Storing tires
M ar k tires when yo u remove t hem to indica te the d irect ion of rota ­
tion . This ens ures yo u to be able to mo unt them co rrectly whe n you
re insta ll them.
Wh en r emoved, t he wheels or tires s hould be sto red in a c ool, dry and
preferably da rk p lace. Sto
re tires in a ver tica l pos it ion if they a re not mounted on rims, in a
hor izonta l position if they are mo unted on r ims.
New tires
N ew tires have to be bro ken in~ & .
Th e tread dep th of new tires may v ary, ac cor ding to t he type an d
make of t ire and the tread pattern.
Hidden damage
Dama ge to t ires and rims is often not readi ly visible . If yo u notice
unusu al v ib rat ion o r the veh icle pulls to one sid e, t his may i ndicate
that one of the tires has been damaged. The tires must be c hecke d
i m medi ately by an a uthor ized A udi deale r or quali fied w or ksh op .
Unidirectional tires
A u nidirectional tire can be identified by arrows on the sidewall, that
point in the d irect io n the tire is des igned to rotate. Yo u m ust follow
t he s peci fied dire ction of ro tation . T his is nece ssary so th at t hese
tires can develop the ir optimum c haracter istics regarding gr ip, road
noise, we ar and hy dropl aning res istance. For more informa tion
~page 341 .
& WARNING
New tires or tires that are old , worn or damaged cannot provide
maximum control and braking ability.
• New tires tend to be slippery and must be broken in. To reduce
the risk of losing control, a collision and serious personal injuries, drive with special care for the first 350 miles (560 km) .
• Driving with worn or damaged tires can lead to loss of control,
sudden tire failure , including a blowout and sudden deflation ,
crashes and serious personal injuries. Have worn or damaged tires
replaced immediately. .,_