brakes AUDI A4 2008 B8 / 4.G User Guide

Intelligent technology 224
WARNING
You should switch off the ESP only if your driving ability and traffic
conditions allow you to do so safely. Please note that, when the
ASR and ESP are switched off, the driven wheels may start to spin,
causing the vehicle to lose grip, in particular on slippery or wet
roads - danger of skidding!
Note
The ASR and ESP cannot be switched off when the adaptive cruise
control (ACC)* is on.BrakesNew brake pads
New brake pads do not give full braking effect for the first 400 km,
they must first be “bedded in”. However, you can compensate for
the slightly reduced braking effect by applying more pressure on
the brake pedal. Avoid placing a heavy load on the brakes during the
running-in period.
We ar
The rate of wear on the brake pads depends a great deal on how you
drive and the conditions in which the vehicle is operated. Negative
factors are, for instance, city traffic, frequent short trips or hard
driving with abrupt starts and stops.
Wet roads; road salt
When you are driving at a speed higher than 80 km/h and have the
windscreen wipers switched on the brake pads are very briefly
brought into contact with the brake discs. This automatic process
which goes unnoticed by the driver is carried out at regular intervals
and is intended to improve braking response in wet conditions.In certain conditions, such as in heavy rain, or after washing the car
or driving through water, the full braking effect can be delayed by
moisture (or in winter by ice) on the discs and brake pads. The
brakes should be “dried” by pressing the pedal to restore full
braking effect.
The effectiveness of the brakes can also be temporarily reduced if
the car is driven for some distance without using the brakes when
there is a lot of salt on the road in winter. The layer of salt that accu-
mulates on the discs and pads can be removed with a few cautious
brake applications.
Corrosion
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 used infrequently, or if
you only drive low mileages without using the brakes very much.
If the brakes are not used frequently, or if corrosion has formed on
the discs, it is advisable to clean off the pads and discs by braking
firmly a few times from a moderately high speed ⇒.
Faults in the brake system
If the brake pedal travel should ever increase suddenly, this may
mean that one of the two brake circuits has failed. Drive immedi-
ately to the nearest qualified workshop and have the fault rectified.
On the way to the dealer, be prepared to use more pressure on the
brake pedal and allow for longer stopping distances.
Low brake fluid level
Malfunctions can occur in the brake system if the brake fluid level is
too low. The brake fluid level is monitored electronically.
Brake servo
The brake servo amplifies the pressure you apply to the brake pedal.
It only works when the engine is running.
document_0900452a81b1b9de.book Seite 224 Donnerstag, 26. Juli 2007 9:16 09

Intelligent technology225
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
WARNING
•
When applying the brakes to clean off deposits on the pads and
discs, select a clear, dry road. Be sure not to inconvenience or
endanger other road users; do not risk an accident.
•
Never let the car coast with the engine switched off (this can
cause accidents).Caution
•
Never let the brakes “drag” by leaving your foot on the pedal
when you do not really intend to brake. This overheats the brakes,
resulting in longer stopping distances and greater wear.
•
Before driving down a long, steep gradient, it is advisable to
reduce speed and move the selector lever to a lower gear. In this
way you will make use of the engine braking effect and relieve the
load on the brakes. If you still have to use the brakes, it is better to
brake firmly at intervals than to apply the brakes continuously.Note
•
If the brake servo is out of action due to a malfunction, or if the
car has to be towed, you will have to press the brake pedal consid-
erably harder to make up for the lack of servo assistance.
•
If you wish to equip the car with accessories such as a front
spoiler or wheel covers, it is important that the flow of air to the
front wheels is not obstructed, otherwise the brakes can overheat.
Power steering (servotronic)The power steering assists the driver when turning the
steering wheel (with the engine running).The power steering assists the driver by reducing the force needed
to turn the steering wheel. The degree of power assistance is
adapted electronically, depending on the speed.If a fault should occur in the servotronic system the power steering
will still operate. The degree of power assistance will, however, no
longer adapt to different speeds. If the electronic regulating system
is not working properly, this is most noticeable when turning the
steering wheel at low speeds (for instance when parking) – more
effort will be required than usual. The fault should be corrected by
a qualified workshop as soon as possible.
The power steering does not function when the engine is switched
off. In this case the steering wheel is very hard to turn.
If the steering is held at its turning limit when the car is stationary,
this will place an excessive load on the power steering system. In
this case, the power steering system will make noises. It will also
reduce the idling speed of the engine.
Caution
Do not keep the steering in the full-lock position for longer than
15 seconds when the engine is running – this could cause damage
to the power steering system.
Note
•
If the power steering should fail at any time or the engine is
switched off (for instance when being towed), the car can still be
steered. However, more effort will be required to turn the steering
wheel.
•
If the system is leaking or malfunctioning, please take the car to
a qualified workshop as soon as possible.
•
The power steering requires a special hydraulic fluid. The fluid
reservoir is located at the front of the engine compartment on the
left ⇒page 256. The correct fluid level in the reservoir is important
for the power steering to function properly. The hydraulic fluid level
is checked at the Inspection Service.
document_0900452a81b1b9de.book Seite 225 Donnerstag, 26. Juli 2007 9:16 09

Your vehicle and the environment229
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Your vehicle and the environmentRunning inA new vehicle should be run in over a distance of 1,500 km. For the
first 1,000 km the engine speed should not exceed 2/3 of the
maximum permissible engine speed – do not use full throttle and do
not tow a trailer or caravan. From 1,000 to 1,500 km you can gradu-
ally increase the engine rpm and road speed.
During its first few hours of running, the internal friction in the
engine is greater than later on when all the moving parts have
bedded down.
How the vehicle is driven for the first 1,500 km also influences the
engine quality. After the first 1,500 km you should continue driving
at moderate engine speeds, in particular when the engine is cold.
This helps to reduce wear and tear on the engine and increases the
potential mileage which can be covered by the engine.
You should also avoid driving with the engine speed too low.
Change down to a lower gear when the engine no longer runs
“smoothly”. Excessively high engine speeds are prevented by an
automatic rev limiter.Emission control systemsCatalytic converter
Applies to vehicles with petrol engine: The vehicle must only be
used with unleaded petrol, otherwise the catalytic converter will be
destroyed.
Never run the tank completely dry. The irregular fuel supply can
cause misfiring, which would allow unburnt fuel to enter the
exhaust system, which could cause overheating and damage the
catalytic converter.Diesel particulate filter
Applies to vehicles with diesel engine: The diesel particulate filter
can filter out almost all soot particles contained in the exhaust gas.
In normal driving conditions the filter is self-cleaning. Should the
self-cleaning function of the filter not be able to operate, e.g. when
the vehicle is continuously used only for short trips, the filter
becomes obstructed with soot and the symbol

for the diesel
particulate filter lights up ⇒page 38.
WARNING
•
Because of the high temperatures which can occur in the emis-
sion control system (catalytic converter or diesel particulate
filter), do not park the vehicle where the exhaust can come into
contact with flammable materials under the car (e.g. on grass or
at the forest edge). - Fire hazard!
•
Do not apply any underseal agents in the area around the
exhaust system - fire hazard!
How to improve economy and minimise pollutionFuel economy, environmental impact and wear on the engine,
brakes and tyres depend largely on the way you drive the vehicle. By
adopting an economical driving style and anticipating the traffic
situation ahead, you can reduce fuel consumption by 10-15%. The
following section gives you some tips on lessening the impact on
the environment and reducing your operating costs at the same
time.
document_0900452a81b1b9de.book Seite 229 Donnerstag, 26. Juli 2007 9:16 09

Your vehicle and the environment 230Anticipate well in advance
A car uses most fuel when accelerating. If you anticipate hazards
and speed changes well in advance, you will need to brake less and
thus accelerate less. Wherever possible, let the car slow down grad-
ually with a gear engaged, for instance when you can see that the
next traffic lights are red. This takes advantage of the engine
braking effect, reducing wear on the brakes and tyres. Emissions
and fuel consumption will drop to zero due to the overrun fuel cut-
off.
Change gear early to save fuel
An effective way of saving fuel is to change up quickly through the
gears. Running the engine at high rpm in the lower gears uses an
unnecessary amount of fuel.
Manual gearbox: Shift up to second gear as soon as possible. If
possible, we recommend shifting up to the next gear at approx.
2,000 rpm.
Automatic gearbox: Press the accelerator slowly and avoid using
the “kick-down” feature.
Avoid driving at high speed
Avoid travelling at top speed. Fuel consumption, exhaust emissions
and noise levels all increase very rapidly at higher speeds. Driving at
moderate speeds will help to save fuel.
Do not let the engine idle for longer than necessary
It is worthwhile switching off the engine when waiting in a traffic
jam, at level crossings or at traffic lights with a long red phase. The
fuel saved after only 30 - 40 seconds is greater than the amount of
fuel needed to restart the engine.
The engine takes a very long time to warm up when it is running at
idling speed. Mechanical wear and pollutant emissions are also
especially high during this initial warm-up phase. It is therefore best
to drive off immediately after starting the engine. Avoid running the
engine at high speed.Regular servicing
Regular servicing can establish a basis for good fuel economy
before you start driving. A well-serviced engine gives you the
benefit of improved fuel efficiency as well as maximum reliability
and an enhanced resale value. A badly tuned engine can consume
up to ten percent more fuel than necessary.
Avoid short trips
The engine and emission control system need to reach their proper
working temperature in order to minimise fuel consumption and
emissions.
A cold engine uses disproportionately more fuel. The engine only
reaches its working temperature after about four kilometres, when
fuel consumption will return to a normal level. This is the reason
why we recommend avoiding short trips wherever possible.
Maintain the correct tyre pressures
Always make sure the tyres are inflated to the correct pressures
⇒page 268 to save fuel. If the tyre pressures are just 0.5 bar too low,
this can increase the fuel consumption by as much as 5 %. Due to
the greater rolling resistance, under-inflation also increases tyre
wear and impairs handling.
Do not use winter tyres all through the year; they will increase fuel
consumption by up to 10 %.
Avoid carrying unnecessary loads
Every kilo of extra weight will increase the fuel consumption, so it is
worth checking the luggage compartment occasionally to make
sure that no unnecessary loads are being transported.
A roof carrier is often left in place for the sake of convenience, even
when it is no longer needed. At a speed of 100-120 km/h your car will
use about 12 % more fuel as a result of the extra wind resistance
caused by the roof carrier - even when it is empty.
document_0900452a81b1b9de.book Seite 230 Donnerstag, 26. Juli 2007 9:16 09

Towing a trailer 234•
The trailer overrun brake must be set correctly. This is important
to ensure that the trailer can be braked correctly, to avoid the vehicle
and trailer “jack-knifing” and to prevent excess braking of the trailer.
•
At low outside temperatures, both the towing vehicle and the
trailer should be fitted with winter tyres.
WARNING
It is essential that you adjust your speed to suit the weather, road
and traffic conditions. Do not let the trailer stabilisation system
tempt you into taking any risks when driving – this can cause acci-
dents.•
The ESP and trailer stabilisation system cannot defy the laws
of physics. This should be kept in mind, particularly on slippery
and wet roads and when towing a trailer with a light load.
•
The trailer stabilisation system is functional, regardless of
whether the trailer has a mechanical overrun brake or not.
•
The trailer stabilisation system is not always able to detect
swaying of trailers with a light load and will therefore not inter-
vene.
•
A trailer can still “jack-knife” on slippery roads with little grip,
even if the towing vehicle is equipped with the trailer stabilisation
system.
•
Trailers with a high centre of gravity may even tip over before
they start to sway sideways.
•
If you are not towing a trailer, but the trailer socket is being
used (e.g. for an illuminated bicycle rack), the trailer stabilisation
system may be activated in extreme driving conditions.
•
Please note the additional information and warnings
⇒page 234.
Notes on towing
Driving with a trailer always requires extra care.Weight distribution
Try to avoid towing a loaded trailer with an unladen vehicle. If this
cannot be avoided, drive extra slowly to allow for the unbalanced
weight distribution.
Speed
The stability of the car and trailer is reduced with increasing speed.
For this reason it is advisable not to drive at the maximum permis-
sible top speed in unfavourable road, weather or wind conditions.
This applies especially on a downhill gradient.
You should always reduce speed immediately if the trailer shows
the slightest sign of swaying. Never try to stop the swaying by accel-
erating further.
Always brake in good time. If the trailer has an overrun brake, apply
the brakes gently at first and then firmly. This will prevent the jerking
that can be caused by the trailer wheels locking. Change down in
good time before going down a steep hill so that you can use the
engine braking effect to slow down the vehicle.
Swaying and pitching can be reduced by stabiliser aids. We recom-
mend having stabiliser aids installed when towing trailers with a
high trailer weight. They can be purchased and installed at an Audi
dealer.
Overheating
When climbing long hills in hot weather with the engine running
fast in low gear, you should keep an eye on the coolant temperature
gauge ⇒page 11. Reduce speed immediately if the needle moves to
the top end of the scale. If the temperature warning lamp
 in the
instrument cluster should start flashing, stop the car and let the
engine cool down by running it at idling speed for a few minutes.
document_0900452a81b1b9de.book Seite 234 Donnerstag, 26. Juli 2007 9:16 09

Care of vehicle and cleaning245
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
WARNING
•
Do not wash the vehicle with the ignition switched on – risk of
accident.
•
Do not clean the underside of the car or inside the wheel arches
without protecting your hands and arms. You may cut yourself on
sharp metal parts.
•
Take care when washing the car during the winter: moisture
and ice on the brakes may affect braking efficiency – this could
cause an accident.Caution
•
Do not wash the vehicle in direct sunlight – otherwise the paint
can be damaged.
•
Do not use insect sponges or abrasive household sponges, etc.
– they can damage the surfaces.
•
The headlights should only be washed with water – do not wipe
them with a dry cloth or sponge. It is best to use soapy water.
•
Never wash tyres with a jet that sprays the water out in a direct
stream. This could damage the tyres – even if the spray is kept at a
distance and only used for a very short time.For the sake of the environment
The car should only be washed in special wash bays. This prevents
oily water from getting into the public drains. In some districts,
washing vehicles anywhere else may be prohibited.Waxing and polishingWaxing
Waxing protects the paintwork. It is time to apply a good coat of wax
when water no longer forms droplets and rolls off the clean paint-
work.Even if a wax solution is used regularly in the car wash, it is advis-
able to protect the paint with a coat of wax at least twice a year.
In the summer, you will find it is much easier to remove dead insects
(which accumulate on the bumper and the front of the bonnet) if the
car has been waxed recently.
Polishing
Polishing is only necessary if the paint has lost its shine, and the
gloss cannot be brought back by putting on wax.
The car must be waxed after polishing if the polish used does not
contain wax compounds to seal the paint.
Caution
Matt painted and plastic parts must not be treated with wax or
polish.Ornamental trim and mouldingsThe metal brightwork on the body is made of aluminium rather than
chrome (for environmental reasons).
Dirt or marks on the trim mouldings should be removed with an
acid-free cleaning agent (do not use a chrome cleaner). Body polish
is also unsuitable for use on trim mouldings. The intensive cleaning
fluids often used before the car goes into a car wash may contain
alkaline substances, which can cause dull or milky patches when
they dry out.
Audi dealers carry stocks of cleaning products which have been
tested for use on your vehicle and are not harmful to the
environment.
document_0900452a81b1b9de.book Seite 245 Donnerstag, 26. Juli 2007 9:16 09

Care of vehicle and cleaning247
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data After washing, the wheels should only be cleaned with an "acid-
free" cleaning agent for alloy wheels. This is available from Audi
dealers and specialist retailers. Never leave the cleaning agent on
the rims for any longer than specified in the instructions before
rinsing it off. If the wheel cleaner fluid contains acid it can attack the
surfaces of the wheel bolts.
Car polish or other abrasive agents should not be used. If the
protective paint coating is damaged by stone chips etc., the
damaged area should be touched up immediately.
WARNING
Please note when cleaning the wheels that water, ice and road salt
can impair the effectiveness of the brakes – this can cause an
accident.Care of interiorSound system / MMI* display screen and MMI control console*The display screen can be cleaned with a soft cloth and a special
“LCD cleaner” (available from retailers of electrical goods). Moisten
the cloth with a small amount of the cleaning fluid.
Clean the MMI control console with a fine brush first to prevent any
dirt from getting in between the control buttons and the housing.
We then recommend wiping the MMI control console using a cloth
moistened with washing-up liquid and water.
Caution
To avoid scratching the screen, do not wipe the display with a dry
cloth.
•
To avoid any possibility of damage, do not let any liquid get
inside the control console.
Plastic parts and leatherettePlastic parts and leatherette can be cleaned with a damp cloth. If
this is not sufficient, plastic parts and leatherette should only be
treated with a special solvent-free plastic cleaner.Textile covers and trim partsTextile covers and trim parts (e.g. seats, door trim) should be
cleaned regularly with a vacuum cleaner. This will remove surface
dirt which could otherwise be rubbed into the textile material
during use. Do not use steam cleaners, as the steam could carry the
dirt deeper into the textile material.
Normal cleaning
We recommend that you use a soft sponge or lint-free, micro-fibre
cloth for normal cleaning. Only use brushes on floor coverings and
mats, as other textile surfaces could become damaged.
In the case of normal surface dirt you can use a foam cleaner. Use a
sponge to spread the foam on the textile surface and to work it into
the material lightly. However, make sure that the textile material
does not become soaking wet. Then dab off the foam with a dry and
absorbent cloth (e.g. a micro-fibre cloth) and vacuum off any
residue once the surface is completely dry.
Removal of stains
To treat stains caused by spilled drinks (coffee, fruit juice or similar)
make up a solution with a mild detergent for sensitive fabrics and
apply it with a sponge. If the stains are difficult to remove, a
washing paste can be applied directly onto the stain and worked
into the fabric. The surface will then have to be wiped with clear
document_0900452a81b1b9de.book Seite 247 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids263
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Changing brake fluid
When required, the brake fluid should be changed by a
competent mechanic with the proper equipment.Brake fluid gradually absorbs moisture from the atmosphere. If the
water content in the brake fluid is too high, this may cause corrosion
in the brake system over time. In addition, the boiling point of the
brake fluid will be considerably reduced. This could adversely affect
the braking ability in certain circumstances.
For this reason the brake fluid must be changed periodically.
Your vehicle's Service Schedule will tell you when the brake fluid has
to be changed.
It is advisable to have the brake fluid changed as part of a regular
Inspection Service at your Audi workshop. They are familiar with the
procedure and have the necessary special tools and spare parts as
well as the proper facilities for disposing of the old fluid.
Use only the genuine brake fluid specified by the factory Qualified
workshops know that the brake fluid “DOT 4” is approved by Audi.
The brake fluid must be fresh and unused.
WARNING
•
Brake fluid is poisonous; store it in the sealed original container
in a safe place out of reach of children.
•
Heavy use of the brakes may cause a vapour lock if the brake
fluid is left in the system for too long. This would seriously affect
the efficiency of the brakes and the safety of the car – risk of acci-
dent.Caution
Please note that brake fluid will attack the paintwork on contact.
For the sake of the environment
If the fluid has to be drained out of the brake system, use an appro-
priate container to catch the used brake fluid and dispose of it in the
proper manner.BatteryGeneral notes
All work on batteries requires specialist knowledge.The battery is virtually maintenance-free. It is checked as part of the
Inspection Service.
We recommend that you replace a battery once it is older than 5
years.
When an airbag is triggered, the battery will, under certain circum-
stances, be disconnected from the on-board power supply for
safety reasons ⇒ in “General notes on airbag system” on
page 201.
Disconnecting the battery
If the battery is disconnected, some of the vehicle's functions will
become inoperative (e.g. electric windows). These functions will
require resetting after the battery is reconnected. For this reason,
the battery should only be disconnected from the vehicle's electrical
system when absolutely necessary.
If the vehicle is not used for long periods
If you do not drive your vehicle for a period of several days or weeks,
the power management will gradually shut off the on-board
systems one by one, or reduce the amount of current they are using.
This limits the amount of power consumed and helps to ensure reli-
able starting even after a long period ⇒page 226.
document_0900452a81b1b9de.book Seite 263 Donnerstag, 26. Juli 2007 9:16 09

General notes 320General notesExplanation of technical dataWhere not otherwise indicated or separately listed, all technical
data apply to vehicles with standard equipment for the German
market. Other figures may apply for special versions and export
models.
Please note that the details listed in the vehicle's registration docu-
ments can be taken as correct.
Engine data
The figures for engine power output are determined according to
EU standards.
Performance figures
The performance figures were measured without equipment which
may influence performance, such as mudflaps or extremely wide-
section tyres.
Kerb weight (unladen weight)
These figures (kerb weight according to the currently applicable
version of EU Directive 92/21/EEC) apply to the vehicle with the tank
90% full, with no special equipment. The figures include an addi-
tional 75 kg to allow for the weight of the driver.
When towing a trailer, the gross vehicle weight may be exceeded by
up to 30 kg and the maximum rear axle weight may be exceeded by
up to 80 kg.
Maximum trailer weights
The maximum trailer weights are calculated in accordance with the
currently applicable version of EU Directive 92/21/EEC.
The figures for a trailer with brakes, on gradients up to 8% are appli-
cable only up to a maximum speed of 80 km/h (even though higher
speeds may be permitted when towing a trailer in some countries).The figures for a trailer with brakes on gradients up to 12% and for
the weight of car and trailer on gradients up to 12% are applicable
up to a maximum speed of 100 km/h. This maximum speed must not
be exceeded even in countries where higher speeds are permitted.
Maximum draw bar loading
The vertical load exerted by the trailer drawbar on the ball joint of
the towing bracket must not exceed 80 kg.
In the interest of safety, we recommend applying the maximum
permitted draw bar weight. The stability of the trailer could be
adversely affected if too little weight is applied.
If the maximum permitted drawbar weight cannot be obtained, e.g.
when using small or light trailers, statutory regulations require that
the drawbar weight be at least 4% of the actual trailer weight (for
single-axle trailers or twin-axle trailers with an axle spacing less
than 1.0 m).
Dimensions1) The height of the vehicle depends on the tyres and suspension.
Take care not to damage low-mounted parts of the car (such as the
spoiler or exhaust system) on steep ramps, uneven road surfaces or
roadside kerbs, etc.
This applies especially when the vehicle is fully laden.Length
mm
4703
Width
mm
1826
Width across mirrors
mm
1953
Height, unladen
1)
mm
1417-1437
document_0900452a81b1b9de.book Seite 320 Donnerstag, 26. Juli 2007 9:16 09

Performance, weights and dimensions323
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Performance, weights and dimensionsPetrol enginesA4 1.8Engine data
Performance figures
WeightsMaximum trailer weights
2)
Engine oil
MG = Manual gearbox / AG = Automatic gearbox1) With slight loss of power2) The specified trailer weights apply only to vehicles with a factory-
fitted towing bracket.
Power output
118 kW at 4500 - 6000 rpm
Maximum torque
250 Nm at 1500 - 4500 rpm
Cylinders, capacity
4 cylinders, 1,798 cm
3
Fuel
Premium unleaded 95 RON or
regular unleaded 91 RON
1)
MG
AG
Maximum speed
km/h
225
218
Acceleration from 0 - 100 km/h
sec.
8.6
8.6
MG
AG
Gross vehicle weight
kg
1960
2000
Kerb weight (unladen weight)
kg
1410
1450
Maximum front axle weight
kg
1035
1060
Maximum rear axle weight
kg
1050
1060
MG
AG
Trailer with brakes on
gradients up to 8%
kg
1500
1500
Trailer with brakes on
gradients up to 12%
kg
1300
1300
Weight of vehicle and
trailer on gradients up to 12%
kg
3330
3370
Trailer without brakes
kg
740
750
LongLife Service
VW 503 00, VW 504 00
Inspection Service
VW 502 00, VW 503 00, VW 504 00
Engine oil capacity
(including filter change)
approx. 4.6 litres
document_0900452a81b1b9de.book Seite 323 Donnerstag, 26. Juli 2007 9:16 09