brake AUDI A8 2017 Service Manual

Driving sa fe ty
A WARNING
Improper seating positions increase the r isk
of serious personal injury and death whenever
a vehicle is being used.
- Always make sure that all vehicle occupants
stay in a proper seat ing position and are
properly restrained whenever the vehicle is
being used.
Driver's and front
passenger's footwell
Important safety instructions
A WARNING
Always ma ke sure that the knee airbag can in­
flate without inter ference. Objects between
yourself and the airbag can increase the risk
of injury in an acc ident by interfering with the
way the airbag deploys or by being pushed in­
to you as the airbag deploys.
- No persons (children) or animals shou ld ride
in the footwell in front of the passenger
seat. If the airbag dep loys, th is can result in
serious or fatal injuries .
- No objects of any k ind shou ld be carried in
the footwell area in front of the driver's or
passenger's seat . Bulky objects (shopping
bags, for example) can hamper or p revent
prope r deployment of the airbag. Small ob­
jects can be th rown through the vehicle if
the a irbag deploys and injure you or your
passengers.
Pedal area
Pedals
The pedals must always be free to move and
must never be interfered with by a floor mat or
any o ther object.
Make sure that all peda ls move freely without in­
terference and that noth ing prevents them from
returning to the ir origina l positions.
O nly use floor mats that leave the peda l area free
and can be secured w it h floor mat fasteners.
212
If a brake circuit fails, increased brake pedal trav ­
el is required to bring the vehicle to a fu ll stop.
A WARNING
Pedals that cannot move freely can cause loss
of vehicle contro l and increase the r isk of seri­
ous injury.
- Never p lace any objects in the drive r's foot­
well. An object could get into the pedal area
and interfere with pedal funct ion. In case of
sudden braking or an acc ident , you would
not be able to b rake o r acce le rate!
- Always make sure that nothing can fall or
move into the driver's footwell.
Floor mats on the driver side
Always use floor mats that can be securely a t­
tached to the floor mat fas teners and do not in­
terfere with the free movement of the pedals .
.,. Make sure that the floor mats are properly se­
cured and cannot move and in terfere w ith the
pedals ¢_& .
Use only floor mats that leave the peda l area un­
obstructed and that are firmly secured so that
they can not s lip out of position . You can obtai n
su itable floor mats from your author ized Audi
Dealer .
Floor mat fasteners are installed in your Aud i.
Floor mats used in yo ur vehicle must be attached
to these fasteners. Properly secur ing the floor
mats will prevent them from sliding into posi­
tions that could interfere with the pedals or im­
pair safe operat ion of your vehicle in other ways .
A WARNING
Pedals that cannot move freely can result in a
loss of vehicle contro l and increase the r is k of
serious pe rsonal injury.
- Always make sure that floo r mats are prop­
erly secured.
- Never place or install floor mats or other floor coverings in the vehicle that cannot be
properly secured in place to preven t them
from s lipping and interfer ing wi th the ped­
als or the ab ility to cont rol the vehicle .

0 co .... N ,..._
N .... 0 0 :c ' -Never place or install floor mats or other
floor coverings on top of already installed
floor mats. Additional floor mats and other
coverings will reduce the size of the pedal
area and interfere with the pedals .
- Always properly reinstall and secure floor
mats that have been taken out for cleaning.
- Always make sure that objects cannot fall
into the driver footwell while the vehicle is
moving . Objects can become trapped under
the brake pedal and accelerator pedal caus­ ing a loss of veh icle control.
Storing cargo correctly
Loading the luggage compartment
All luggage and other objects must be properly
stowed and secured in the luggage compart­
ment.
L oose items in the luggage compartment can
shift suddenly, changing vehicle handling charac­
teristics. Loose items can also increase the risk of
serious personal injury in a sudden vehicle ma­
neuver or in a collision.
.. Distribute the load evenly in the luggage com­
partment.
.. Always place and properly secure heavy items in
the luggage compartment as far forward as
possible.
.,. Secure luggage items using the tie-downs pro­
vided
¢ page 65.
A WARNING
Improperly stored luggage or other items can
fly through the vehicle causing serious per­ sonal injury in the event of hard braking or an
accident. To help reduce the risk of serious
personal injury:
- Always put objects, for example, luggage or
other heavy items in the luggage compart­
ment.
- Always secure objects in the luggage com­
partment using the tie-down hooks and
suitable straps .
Driving safety
A WARNING
Heavy loads will influence the way your vehi­
cle handles. To help reduce the risk of a loss
of control lead ing to serious personal injury:
- Always keep in m ind when transporting
heavy objects, that a change in the center of
gravity can also cause changes in vehicle handling:
- Always distribute the load as evenly as
possible .
- Place heavy objects as far forward in the
luggage compartment as possible.
- Never exceed the Gross Axle Weight Rating
or the Gross Vehicle Weight Rating specified
on the safety compliance sticker on the left
door jamb. Exceeding permissible weight
standards can cause the vehicle to slide and handle differently.
- Please observe information on safe driving
¢page 207.
A WARNING
To help prevent poisonous exhaust gas from
being drawn into the vehicle, always keep the
rear lid closed while driving .
- Never transport objects larger than those
f itting completely into the luggage area be­
cause the rear lid cannot be fully closed.
- If you absolutely must drive with the rear lid open, observe the following notes to reduce
the risk of poisoning:
- Close all windows,
- Close the power roof,
- Open all air outlets in the instrument pan-
el,
- Switch off the air recirculation
,
- Set the fresh air fan to the highest speed .
A WARNING
Always make sure that the doors, all win­
dows, the power roof and the rear lid are se­
curely closed and locked to reduce the r isk of
in jury when the vehicle is not being used.
- After closing the rear lid, always make sure
that it is properly closed and locked.
-
213

Checking and Filling
-Set the parking brake.
- Select the P selector lever position.
- Let the engine cool down.
- Never open the hood when there is steam or
coolant escaping from the engine compart­
ment, because there is a risk that you could
be burned. Wait until no steam or coolant is
escaping.
- Keep children away from the engine com­
partment.
- Never spill fluids on a hot engine. These flu­
ids (such as the anti-freezing agent con­
tained in the coolant) can ignite.
- Avoid short circuits in the electrical system.
- When working in the engine compartment,
remember that the radiator fan can switch
on even if the ignition is switched off, which
increases the risk of personal injury.
- Never open the cap on the coolant expan­
sion tank when the engine is warm. The
cooling system is under pressure.
- To protect your face, hands, and arms from
hot steam or coolant, cover the cap with a
large cloth when opening.
- Do not remove the engine cover under any
circumstances. This increases the risk of
burns.
- If tests need to be performed with the en­
gine running, there is additional danger due
to moving components (such as the ribbed
belt, alternator and radiator fan) and from
the high-voltage ignition system .
- Do not under any circumstances activate the
throttle inadvertently (for example, by hand
from the engine compartment) if the vehi­
cle is stationary but the engine is running
and a gear is engaged. Otherwise, the vehi­
cle will start to move immediately and this
could result in an accident.
- Pay attention to the following warnings list­
ed when work on the fuel system or on the
electrical equipment is required.
- Do not smoke .
- Never work near open flames.
- Always have a working fire extinguisher
nearby
- All work on the battery or electrical system
in your vehicle can result in injuries, chemi-
272
cal burns, accidents or burns. Because of
this, all work must be performed
only by an
authorized Audi dealer or authorized Audi
Service Facility .
- To reduce the risk of electric shock and in­
jury, never touch the following components when the engine is running or is being start­
ed:
- Ignition cable
- Other components in the electronic high-
voltage ignition system
- If you must check or perform work on the
engine while it is running:
- Set the parking brake and place the selec­ tor lever in the P (park) position first.
- Always proceed with extreme caution so
that clothing, jewelry or long hair do not
become caught in the radiator fan, fan
belt or other moving components or do
not come into contact with hot compo­
nents . Tie back long hair before beginning
work and do not wear clothing that can
hang down into the engine .
- Limit your exposure to exhaust and chemi­
cals to as short a time as possible
c:> ,&. .
.&_ WARNING
California Proposition 65 Warning:
- Engine exhaust, some of its constituents,
and certain vehicle components contain or
emit chemicals known to the State of Cali­
fornia to cause cancer and birth defects and
reproductive harm. In addition, certain flu­
ids contained in vehicles and certain prod­
ucts of component wear contain or emit
chemicals known to the State of California
to cause cancer and birth defects or other
reproductive harm .
- Battery posts, terminals and related acces­
sories contain lead and lead compounds,
chemicals known to the State of California
to cause cancer and reproductive harms .
Wash hands after handling.

Checking and Filling
Engine compartment overview
The most important check points.
Fig. 259 Typical location of the rese rvoir and the engine o il fil le r open ing
(D Washer fluid reservoir (Q) c::> page 281
@ Jump start point(-) with hex head screw
c::> page 280, c::> page 32 7
@ Jump start point( +) under a cover
c> page 280, c::> page 32 7
@ Engine oil label* with VW standard
c> page 274
® Eng ine oil filler opening(~) c> page 276
@ Brake fluid reservoir((()}) c::> page 2 79
(j) Coolant reservoir (-L) c::> page 2 78
The engine oil fill ing opening (item@) may be
located in a different area depending on the en­
gine version.
A WARNING
Read and follow all WARNINGS before check­
ing anything in the engine compartment
c::> &.
in Working in the engine compartment on
page 271.
274
Engine oil
Engine oil specifications
The engine oil used must conform to exact speci­
fications.
The service interval display in the instrumen t
cluster of your vehicle will inform you when it is
time for an o il change. We recommend that you
have your oi l changed by an authorized Audi Se rv­
ice Advisor.
If you must add oil between oil changes, use an
oi l that matches the Audi oil quality standard
listed on the sticker. The sticker is located at the
front of the eng ine compartment
c::> page 274,
fig. 259
Audi recommends
~ Castrol /fg/j;Sf.g;fg f'r Audi recommends Longlife high performance
engine oil from Aud i Genuine Parts
liJI,

C)
_& WARNING
-The cooling system is under pressure. Do
not open the coolant expansion tank cap
when the engine is hot. This increases the
risk of burns .
- The coolant add itive and the coolant can be
dangerous to your health. For this reason,
keep the coolant in the original container
and away from children. There is a risk of
poisoning.
- When working in the engine compartment,
remember that the radiator fan can sw itch
on even if the ignition is switched off, which
increases the risk of injury.
CD Note
Do not add coolant if the expansion tank is
empty. Air could enter the cooling system and
damage the engine. If this is the case, do not
continue driv ing. See an authorized Audi deal­
er or authorized Audi Service Facility for assis­
tance.
Brake fluid
N
N
-N
" co IXl
F ig. 262 Engine compartment: cap on brake fluid re servoir
Observe the safety precautions c:> &. in Working
in the engine compartment on page 2 71.
Checking the brake fluid level
" Read the brake fluid level on the brake fluid
reservoir
c:> page 2 74, fig. 259. The brake fluid
level must be between the MIN and MAX mark­
ings
c:> &_ .
~ The brake fluid level is mon itored automatically .
" N ...... 0 0 :r Checking and Filling
Changing the brake fluid
Have the brake fluid changed regularly by an au­
thorized Audi dealer or authorized Audi Service
Facility.
A WARNING
-
- If the brake fluid level is below the MIN
marking, it can impair the braking effect
and driving safety, which increase the risk of
an accident . Do not continue dr iving. See an
author ized Audi dealer or author ized Audi
Service Facility for assistance.
- If the brake fluid is old, bubbles may form
in the brake system dur ing heavy braking.
This would impair braking performance and
driving safety, which increases the r isk of an
accident.
- To ensure the brake system functions cor­
rectly, only use brake fluids that comply
with VW standard 50114 or FM VSS -116 DOT 4.
CD Note
-If the brake f luid level is above the MAX
marking, brake f luid may leak out over the
edge of the reservoir and result in damage
to the vehicle.
- Do not get any brake fluid on the vehicle
paint, because it wi ll corrode the paint.
Battery
General warnings about batteries
Because of the complex power supply, all wo rk
on batter ies such as disconnecting, replac ing,
etc. should
only be performed by an authorized
Audi dealer or authorized Audi Service Fac il ity
c:> & .
The term "vehicle battery" refers to the 12 Volt
battery in your vehicle.
Detailed warnings for the vehicle battery:
® Wear eye protection.
I.)._ Bat~ery acid is highly corrosiv~. Wear pro-
~ tect1ve gloves and eye protection. Ill-
279

able to provide you with more in­
formation .
® Mud and snow capability
"M/5" or "M+S" indicates the tire
has properties making it suitable
to drive in mud or snow .
& indi­
cates a winter tire .
@Composition of the tire cord
and materials
The number of plies indicates the
number of rubberized fabric lay­
ers in the tire. In general: the
more layers, the more weight a
tire can carry . Tire manufacturers
must also specify the materials
used in the tire. These inc lude
steel, nylon, polyester and other
materials.
@ Maximum permitted load
This number indicates the max i­
mum load in kilograms and
pounds that the tire can carry.
@ Uniform tire quality grade
standards for treadwear,
traction and temperature resistance
Tread wear, traction and temper ­
ature ranges ¢
page 300.
0 @ Running direction
"' -~ The arrows indicate the running
-~ direction of unidirectional tires . ...
Wheels
You must always follow the speci­
fied runn ing d irect ion
¢ page 319 .
@ Maximum permitted
inflation pressure
This number indicates the maxi ­
mum pressure to which a tire can
be inflated unde r normal operat­
ing condit ions.
Glossary of tire and loading
terminology
Accessory weight
means the comb ined weigh t (in
excess of those standard items
which may be replaced) of auto­
matic transm ission, power steer­
ing , power brakes, power win­
dows, power seats, radio, and
heater, to the extent that these
items are available as facto ry-in­
stalled equipment (whether in ­
stalled or not) .
Aspect ratio
means the ratio of the heigh t to
the width of the tire in percent .
Numbers of 55 or lowe r indicate a
low sidewa ll for improved steer­
ing response and better overall
handling on dry pavement. .,.
285

0
"' -N
" N
-0
0
:c ...
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight, and
(d) Production options we ight
Ma ximum (permissible)
inflation pressure
means the maximum cold infla­
tion pressure to which a t ire may
be inflated. Also called "maxi­
mum inflation pressure."
Normal occupant weight
means 150 lbs. (68 kilograms)
times the number of occupants
seated in the veh icle up to the to­
tal seating capacity of your vehi­ c le.
Occupant distribution
means distribution of occupants
in a vehicle.
Outer diameter
means the overall diameter of an
inflated new tire.
Overall width
means the linear distance be­
tween the exteriors of the side­
walls of an inflated tire, including
elevations due to labeling, deco­
rations, or protective bands or
ribs .
Wheels
Ply
means a layer of rubber-coated
parallel cords .
Production options weight
means the combined weight of
those installed regular production
options weighing over 5 lbs. (2.3 kg) in excess of those standard
items which they replace, not pre­
viously considered in curb weight
or accessory weight, including
heavy duty brakes, ride levelers,
roof rack, heavy duty battery, and
special trim .
Radial ply tire
means a pneumatic tire in which
the ply cords that extend to the beads are laid at substantially 90
degrees to the centerline of the
tread.
Recommended inflation
pressure
see ~ page 286, Cold tire infla­
tion pressure .
Reinforced tire
means a tire designed to operate
at higher loads and at higher in­
flation pressures than the corre­ sponding standard tire. Rein ­
forced tires may be identified as .,.
287

0 a, .... N ,.... N .... g :r ..
use a spare tire* that is the same
circumference as the regular
tires.
&_ WARNING -
-Only use tire/rim combina­ tions and suitable wheel bolts
that have been approved by
Audi. Otherwise, damage to
the vehicle and an accident
could result.
-For technical reasons, it is not
possible to use tires from oth­
er vehicles -in some cases,
you cannot even use tires from
the same vehicle model.
-Make sure that the tires you
select have enough clearance
to the vehicle. Replacement
tires should not be chosen
simply based on the nominal
size, because tires with a dif­
ferent construction can differ greatly even if they are the
same size. If there is not
enough clearance, the tires or
the vehicle can be damaged
and this can reduce driving
safety and increase the risk of
an accident .
-Only use tires that are more
than six years old when abso-
Wheels
lutely necessary and drive
carefully when doing so .
-Do not use run-flat tires on
your vehicle . Using them when
not permitted can lead to ve­
hicle damage or accidents.
-If you install wheel covers on
the vehicle, make sure they al­ low enough air circulation to
cool the brake system. If they
do not, this could increase the
risk of an accident.
Tire wear/damage
Fig. 266 T ire profile: treadwear indica­
tor
Tire wear
Check the tires regularly for wear.
-Inflation pressure that is too low
or high can increase tire wear
considerably.
-Driving quickly through curves, rapid acceleration and heavy
braking increase tire wear.
291

Wheels
sure that load limits are not ex­
ceeded. Vehicle load includes ev­
erybody and everything in and on
the vehicle. These load limits are
technically referred to as the vehi­
cle's
Gross Vehicle Weight Rat­
ing
("GVWR").
The "GVWR" includes the weight
of the basic vehicle, all factory in­
stalled accessories, a full tank of
fuel, oil, coolant and other fluids plus maximum load. The maxi­
mum load includes the number of
passengers that the vehicle is in­
tended to carry ("seating capaci­
ty") with an assumed weight of
150 lbs. (68 kg) for each passen­
ger at a designated seating posi­
tion and the total weight of any luggage in the vehicle. If you tow
a trailer, the weight of the trailer
hitch and the tongue weight of
the loaded trailer must be includ­
ed as part of the vehicle load.
The
Gross Axle Weight Rating
("GAWR") is the maximum load
that can be applied at each of the
vehicle's two axles.
The fact that there is an upper
limit to your vehicle's Gross Vehi­
cle Weight Rating means that the
total weight of whatever is being
296
carried in the vehicle (including
the weight of a trailer hitch and the tongue weight of the loaded
trailer) is limited. The more pas­
sengers in the vehicle or passen­
gers who are heavier than the
standard weights assumed mean
that less weight can be carried as l uggage .
The Gross Vehicle Weight Rating
and the Gross Axle Weight Rating
are listed on the safety compli­
ance sticker label located on the
driver's side B-pillar
¢ page 293,
fig. 267.
.&_ WARNING
-
Overloading a vehicle can cause
loss of vehicle control, a crash
or other accident, serious per­
sonal injury, and even death.
-Carrying more weight than
your vehicle was designed to
carry will prevent the vehicle
from handling properly and increase the risk of the loss of
vehicle control.
-The brakes on a vehicle that
has been overloaded may not
be able to stop the vehicle
within a safe distance.

0 co .... N ,..... N .... 0 0 :c ' & 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 . This in­
creases the risk of an accident . The brakes
must be dried first with a few careful brake
applications.
(D 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 reduce the risk of paint damage, do not
wash the vehicle in direct sunlight.
-
Care and cleaning
-To reduce the risk of damage, do not wash
the power top with a pressure washer.
- 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 protective wax. It can destroy
the matte finish 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 tables. The
information contained there is simply recom­
mendations. For questions or for components that are
not listed , consult an authorized Audi
dealer or authorized Audi Service Facility. Also
follow the information found in¢& .
Exterior cleaning
Component Situation Solution
Windshield wiper
Deposits ¢ page 51
blades
Headlights/
Deposits Soft sponge with
a mild soap solutiona)
Tail lights
Sensors/
Deposits Sensors: soft cloth with solvent-free cleaning solution
camera lenses Camera lenses: soft cloth with alcohol-free cleaning solu-
tion
Snow/ice Hand brush/solvent-free de-icing spray
Wheels Road salt Water
Brake dust Acid-free special cleaning solution
307