2021 AUDI A8 service

Checking and Filling

@) Note
— Before the start of winter, have an author-
ized Audi dealer or authorized Audi Service
Facility check if the coolant additive in your
vehicle matches the percentage appropriate
for the climate. This is especially important
when driving in colder climates.
— If the G12evo coolant additive is not availa-
ble in an emergency, do not add any other
additive. You could damage the engine. If
this happens, only use distilled water and
restore the correct mixture ratio with the
specified coolant additive as soon as possi-
ble.
— Only refill with new coolant.
— Radiator sealant must not be mixed with
the coolant.
— You can continue driving if the permitted
G12evo coolant additive was not added.
However, go to an authorized Audi dealer or
authorized Audi Service Facility immediately
to have the coolant replaced to reduce the
risk of engine damage.
— Due to the risk of engine damage, the cool-
ing system should only be refilled by an au-
thorized Audi dealer or authorized Audi
Service Facility. An authorized Audi dealer or
authorized Audi Service Facility can also pro-
vide you with important information about
the recommended coolant additive.

RAZ-0540

MIN


Fig. 183 Engine compartment - Coolant expansion tank:
@ cover with release button; @) markings
Observe the safety precautions > page 274, Gen-
eral information.
282
Applies to: vehicles with plug-in hybrid drive:
Your vehicle has two coolant expansion tanks
that are separate from each other > page 277,
fig. 181. One expansion tank for the combustion
engine and one tank for the high-voltage system.
The coolant expansion tank for the high-voltage
system is sealed and must not be opened > /\
and> A\.
Checking the coolant level
> Park the vehicle on a level surface.
> Switch the ignition off.
> Open the hood > page 276.
> Check the coolant level in the coolant expan-
sion tank > page 277, fig. 181 using the outer
markings (2) > fig. 183. The coolant level must
be between the markings (2) when the engine is
cold. When the engine is warm it can be slight-
ly above the upper marking.
> Conventional drive system: When you add cool-
ant to the expansion tank, please refer to
=> page 281, Cooling system.
>» Plug-in hybrid drive: If you add coolant to the
coolant expansion tank for the combustion en-
gine, see > page 281, Cooling system.
» Plug-in hybrid drive: If coolant is missing from
the high-voltage system coolant expansion
tank, do not continue driving. Contact an au-
thorized Audi dealer or authorized Audi Service
Facility immediately > A\.
Adding coolant
Applies to: coolant expansion tank for combustion engine
When adding coolant to the combustion engine
expansion tank, please observe the following in-
structions.
Requirement: there must be a residual amount of
coolant in the expansion tank >@).
If you must add coolant, use a mixture of water
and coolant additive. Audi recommends mixing
the coolant additive with distilled water.
> Allow the engine to cool.
> Place a large, thick towel on the coolant expan-
sion tank cap.
> Push the release button @ > fig. 183 on the
cap and carefully turn it to the left until you
feel resistance > /\.

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Checking and Filling

> Push the release button again and remove the
cap completely.
> Add coolant mixed in the correct ratio
=> page 281 up to the MAX marking.
> Make sure that the fluid level remains stable.
Add more coolant if necessary.
> Turn the cap to the right to tighten it until you
feel resistance a second time.
Coolant loss usually indicates that there is a leak.
Immediately drive your vehicle to an authorized
Audi dealer or authorized Audi Service Facility
and have the cooling system inspected. If the
cooling system is not leaking, coolant loss can re-
sult from the coolant boiling due overheating
and then being forced out of the cooling system.

der any circumstances > page 277, fig. 181.
If the coolant expansion tank for the high-
voltage system is not sealed, please contact
an authorized Audi dealer or authorized
Audi Service Facility.
— When adding coolant, it may leak into the
inside of high-voltage components and
cause a short circuit, increasing the risk of

fire.


ZA WARNING
— The engine compartment in any vehicle is a
potentially dangerous area. Stop the engine,
switch the ignition off, and allow the engine
to cool before working in the engine com-
partment. Always follow the information
found in > page 274, General information.
— Never open the hood if you can see or hear
steam or coolant escaping from the engine
compartment. This increases the risk of
burns. The cooling system is under pressure.
When you no longer see or hear steam or
coolant escaping, you may open the engine
compartment with caution.
— 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 injury.
— Coolant additive and coolant can be danger-
ous to your health. For this reason, store the
coolant in the original container and away
from children. There is a risk of poisoning.
CG) Note
Do not continue driving if the coolant expan-
sion tank is empty. Do not add any coolant,
because air could enter the cooling system
and damage the engine. See an authorized
Audi dealer or authorized Audi Service Facility
for assistance.
Brake fluid

BFV-0229|




ZA WARNING
Applies to: vehicles with plug-in hybrid drive
The coolant expansion tank for the high-volt-
age system may only be opened or filled by an
authorized Audi dealer or authorized Audi
Service Facility.
— The coolant expansion tank cap is equipped
with a seal that must never be removed un-


Fig. 184 Engine compartment: cap on brake fluid reservoir
Observe the safety precautions > page 274, Gen-
eral information.
Checking the brake fluid level
> Slide the cover that is located below the wind-
shield wipers on the driver's side toward the
windshield and remove the cover.
> Read the brake fluid level on the brake fluid res-
ervoir > page 277, fig. 181. The brake fluid lev-
el must be between the MIN and MAX markings
oA.
The brake fluid level is monitored automatically.
Messages
EG 7 @ Brakes: stop vehicle and check brake
fluid level
283
>

Checking and Filling

Stop the vehicle and check the brake fluid level.
See an authorized Audi dealer or authorized Audi
Service Facility for assistance.
Changing the brake fluid
Brake fluid should be changed at regular inter-
vals. Have the brake fluid changed by an author-
ized Audi dealer or authorized Audi Service Facili-
ty. The authorized Audi dealer or authorized Audi
Service Facility will inform you of the replace-
ment intervals.

ZA\ 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 driving. See an au-
thorized Audi dealer or authorized Audi
Service Facility for assistance.
— If the brake fluid is old, bubbles may form in
the brake system during heavy braking. This
could impair braking performance and driv-
ing safety, which increases the risk of an ac-
cident.
— The brake fluid in your vehicle must meet
the standard VW 501 14 and is available at
an authorized Audi dealer or authorized
Audi Service Facility. If this brake fluid is not
available, another high-grade brake fluid of
equivalent quality may be used, and it must
meet the U.S. Federal Motor Vehicle Stand-
ard (FMVSS) 116 DOT 4, Class 6.

@) Note
— If the brake fluid level is above the MAX
marking, brake fluid may leak out over the
edge of the reservoir and result in damage
to the vehicle.
— Do not allow any brake fluid to come into
contact with the vehicle paint, because it
will corrode the paint.
Electrical system
If the = / B or = indicator light turns on,
there is a malfunction in the power supply, the
battery, or the vehicle electrical system.
284
= / B Electrical system: malfunction! Safely
stop vehicle
Do not continue driving and switch the ignition
off > A\. See an authorized Audi dealer or author-
ized Audi Service Facility for assistance.
= Electrical system: malfunction! Restart not
possible. Please contact Service
If you switch the ignition off, you will not be able
to restart the vehicle. Vehicle functions or driving
stability may be limited. Drive to an authorized
Audi dealer or authorized Audi Service Facility im-
mediately.
=} Electrical system: malfunction! Please con-
tact Service
Switch off all electrical equipment that is not
needed. If necessary, some equipment will be
switched off automatically. Vehicle functions or
driving stability may be limited. Drive to an au-
thorized Audi dealer or authorized Audi Service
Facility immediately.
= Electrical system: low battery charge. Bat-
tery
will be charged while driving
The starting ability may be impaired.
If this message turns off after a little while, the
vehicle battery has charged enough while driving.
If this message does not turn off, drive immedi-
ately to an authorized Audi dealer or authorized
Audi Service Facility.

ZA\ WARNING
When there is an electrical system malfunc-
tion, vehicle functions may not work and driv-
ing stability may be limited, which increases
the risk of an accident. Do not continue driv-
ing and switch the ignition off. See an author-
ized Audi dealer or authorized Audi Service Fa-

cility for assistance.

Battery
Battery general information
Because of the complex power supply, all work on
batteries such as disconnecting, replacing, etc., >

4N0012721BF
Checking and Filling

should only be performed by an authorized Audi
dealer or authorized Audi Service Facility > A\.
Multiple batteries with different technologies
may be installed in your vehicle:
— Vehicle battery (for example, for starting the
engine, basic power supply) > page 285, 12
Volt vehicle battery or > page 286, Other bat-
tery types
— Auxiliary battery (for example, for recuperation
or optional equipment) > page 286, Other bat-
tery types
— Plug-in hybrid drive: High-voltage battery (for
example, for electric driving) > page 131, In-
troduction.
Not running the vehicle for long periods of
time
The battery will gradually drain if the vehicle
does not run for long periods of time. To ensure
that the vehicle can still be started, the electrical
equipment will be limited or switched off. Some
convenience functions, such as interior lighting
or power seat adjustment, may not be available
under certain circumstances. The convenience
functions will be available again when you start
the
engine.
Even when electrical equipment is switched off,
the equipment can still drain the battery if the
vehicle is not driven for long periods of time.
Deep draining results in a chemical reaction that
destroys the inside of the battery. The battery
must be charged every month to prevent this
= page 286. Contact an authorized Audi dealer or
authorized Audi Service Facility for more infor-
mation.
Winter operation
Cold weather places an especially high load on
the 12 Volt vehicle battery. Have the battery
checked by an authorized Audi dealer or author-
ized Audi Service Facility before cold weather be-
gins.

this, all work must be performed only by an
authorized Audi dealer or authorized Audi
Service Facility.
— Never connect a charging cable or jump
start cable directly to the 12 Volt vehicle
battery. Only use the connections in the en-
gine compartment > page 286.

Z\ WARNING
California Proposition 65 Warning:
— 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.
@) Note
— If the vehicle will be parked for long periods
of time, protect the battery against the cold
so that it will not be destroyed by “freezing”
=> page 286, Charging the 12 Volt vehicle
battery.
— There are electrical components under the
cargo floor behind a trim panel that warm
up during operation. To reduce the risk of
the components overheating, do not store
objects such as blankets under the cargo
floor. If the components overheat, they will
switch off temporarily. This will be indicated
by a message that will be displayed in the
instrument cluster until the temperature re-
turns to normal.
12 Volt vehicle battery
Explanation of warnings:


Always wear eye protection.

Battery acid is highly corrosive. Always
wear protective gloves and eye protection.

Fire, sparks, open flame, and smoking are
forbidden.

Z\ WARNING
— All work on the battery or electrical system
in your vehicle can result in injuries, chemi-
cal burns, accidents, or burns. Because of

A highly explosive mixture of gases can
form when charging batteries. >
@
>
©

285

Checking and Filling


Always keep children away from battery
acid and the battery. @
@/
oo

Always follow the instructions in the oper-
ating manual.

@ For the sake of the environment
2 ¥ Lead-acid batteries must be disposed of
using methods that will not harm the environ-
ment. Do not dispose of them in household
trash. They contain harmful substances, such
as sulfuric acid and lead, and also recyclable
raw materials. Contact an authorized Audi
dealer or authorized Audi Service Facility for
more information.
Other battery types
Explanation of warnings:
® ®
@/
oo

Fire, sparks, open flame, and smoking are
forbidden.
Always keep children away from battery
acid and the battery.
Always follow the instructions in the oper-
ating manual.




ZA WARNING
All work on the batteries must only be per-
formed by an authorized Audi dealer or au-
thorized Audi Service Facility.
— Gases that escape from these different bat-
tery types can be poisonous or flammable.
— The contents of these battery types can be
corrosive. If any battery contents come into
contact with the skin, flush the affected
area for at least 15 minutes with clean wa-
ter. Then wash the affected area with soap.
Have the affected area examined by a medi-
cal professional.
@) Note
Components must not be connected to the
battery terminals and wires on these battery
types because this increases the risk of dam-
age, for example due to overvoltage.

286
@) For the sake of the environment

OE These types of batteries must be dis-
posed of using methods that will not harm
the environment. Do not dispose of them in
household trash. They contain harmful sub-
stances and recyclable raw materials. Contact
an authorized Audi dealer or authorized Audi
Service Facility for more information.
arging the 12 Volt vehicle battery

Fig. 185 Engine compartment: connectors for a charger or
jump start cables
Observe the safety precautions > page 274, Gen-
eral information, > /\ in Battery general infor-
mation on page 285 and > /\.
Requirement: only use chargers with a maximum
charging current of 14.8 volts. The battery ca-
bles remain connected.
The charging cable connections are located in the
motor compartment. The ground point ©) is al-
ways located on the vehicle body.
> Switch off the ignition and all electrical equip-
ment.
> Open the hood > page 276.
» Press the release lever on the positive terminal
and fold the cover upward > fig. 185.
> Clamp the charger terminal clamps to the jump
start pins according to the instructions. (Hex
head bolt under a cover (), ground point on the
vehicle body ©)).
> Insert the power cable for the charging device
into the socket and switch the device on.
> At the end of the charging process, switch the
charger off and pull the power cable out of the
socket.
» Remove the charging device terminal clamps. >

4N0012721BF
Checking and Filling

> Close the cover on the positive terminal.
> Close the hood > page 276.

ZA WARNING
— Never connect a charging cable or jump
start cable directly to the 12 Volt vehicle
battery. Only use the connections in the en-
gine compartment > page 286.
— A highly explosive mixture of gases can form
when charging batteries. Only charge the
battery in well-ventilated areas.
— A drained battery can freeze at tempera-
tures around 32 °F (0 °C). Do not charge or
use a frozen or thawed battery. If ice forms,
the battery housing can crack and battery
electrolyte can leak out, which increases the
risk of an explosion and chemical burns.
Contact an authorized Audi dealer or author-
ized Audi Service Facility for more informa-
tion.
— Do not connect or disconnect the charging
cable while charging because this increases
the risk of an explosion.

@) Tips
Read all of the manufacturer's instructions
for the charger before charging the battery.
Windshield washer
system

B4M-0135)

Fig. 186 Engine compartment: washer fluid reservoir cap
Observe the safety precautions > page 274, Gen-
eral information.
The windshield washer reservoir <> contains the
cleaning solution for the windshield and the
headlight washer system* > fig. 186,
= page 277. The reservoir capacity can be found
in > page 344.
To reduce the risk of lime scale deposits on the
spray nozzles, use clean water with low amounts
of calcium. Always add window cleaner to the wa-
ter. When the outside temperatures are cold, an
anti-freezing agent should be added to the water
so that it does not freeze.
Messages
|} Please add washer fluid
Fill the washer fluid for the windshield washer
system and the headlight washer system* when
the ignition is switched off.
CG) Note
—The concentration of anti-freezing agent
must be adjusted to the vehicle operating
conditions and the climate. A concentration
that is too high can lead to vehicle damage.
— Never add radiator anti-freeze or other addi-
tives to the washer fluid.
— Do not use a glass cleaner that contains
paint solvents, because this could damage
the paint.
Service interval display
The service interval display detects when your ve-
hicle is due for service.
The service interval display works in two stages:
— Inspection or oil change reminder: after driv-
ing a certain distance, a message appears in the
instrument cluster display each time the igni-
tion is switched on or off. The remaining dis-
tance or time is displayed briefly.
— Inspection or oil change due: if your vehicle
has reached an inspection or oil change interval
or both intervals at the same time, the mes-
sage Inspection due! or Oil change due! or Oil
change and inspection due! appears briefly af-
ter switching the ignition on or off.
Checking service intervals
You can check the remaining distance or time un-
til the next oil change or next inspection in the
Infotainment system.
287

Checking and Filling

Applies to MMI: Select on the home screen: VE-
HICLE > Settings & Service > Service intervals.
Resetting the indicator
An authorized Audi dealer or authorized Audi
Service Facility will reset the service interval dis-
play after performing service.
If you have changed the oil yourself, you must re-
set the oil change interval.
Applies to: MMI: To reset the display, select on
the home screen: VEHICLE > Settings & Service
> Service intervals.
@) Note
— Only reset the oil change indicator if the oil
was changed.
— Following the service intervals is critical to
maintaining the service life and value of
your vehicle, especially the engine. Even if
the mileage on the vehicle is low, do not ex-
ceed the time for the next service.
288

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Wheels

@ US DOT number (TIN) and
manufacture date
The manufacture date is listed on
the tire sidewall (it may only ap-
pear on the inner side of the tire):
DOT... 2220...
means, for example, that the tire
was produced in the 22nd week of
the year 2020.
Audi Original Tires
Audi Original equipment tires
with the designation “AO” have
been specially matched to your
Audi. When used correctly, these
tires meet the highest standards
for safety and handling. An au-
thorized Audi dealer or author-
ized Audi Service Facility will be
able to provide you with more in-
formation.
@) Mud and snow capability
“M/S” or “M+S” indicates the tire
is suitable for driving on mud and
snow. /4\ indicates 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 include
steel, nylon, polyester and other
materials.
@) Maximum permitted load
This number indicates the maxi-
mum load in kilograms and
pounds that the tire can carry.
@ Uniform tire quality grade
standards for treadwear,
traction and temperature
resistance
Treadwear, traction, and tempera-
ture ranges > page 306.
@ Running direction
The arrows indicate the running
direction of unidirectional tires.
You must always follow the speci-
fied running direction
=> page 322.
Maximum permitted
inflation pressure
This number indicates the maxi-
mum pressure to which a tire can
be inflated under normal operat-
ing conditions.
291