brake AUDI S4 2018 Repair Manual

Wheel s
® Mud and snow capability
"M/5" or "M+S" indicates the tire
is sui table for driving on mud and
snow.
& 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 t ire. 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, po lyester 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 resist ance
Treadwear, traction and tempera­
ture
ranges ¢ page 351.
@ Running direction
The arrows indicate the running
direction of unidirectional t ires .
You must always follow the speci­
fied running direction
¢page 366 .
336
@ Maximum permitted
inflation pressure
This number indicates the maxi­
mum pressure to which a tire can
be inflated under normal operat ­
ing condit ions.
Glossary of tire and loading
terminology
Acces sory we ight
means the combined weight (in
excess of those standard items
which may be replaced) of auto­ matic transmission, power steer­
ing, power brakes, power win­
dows, power seats, radio, and
heater, to the extent that these
items are available as factory-in­
stalled equipment (whether in ­
stalled or not) .
Aspect ratio
means the ratio of the height to
the width of the tire in percent .
Numbers of 55 or lower indicate a
low sidewall for improved steer­
ing response and better overall
handling on dry pavement.
Bead
means the part of the tire that is
made of steel wires, wrapped or
reinforced by ply cords and that is
shaped to fit the r im .
...

Wheel s
Maximum (permissible)
inflation pressure
means the max imum 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 k ilograms)
times the number of occupants seated in the vehicle up to the to­
tal seating capacity of your vehi­
cle .
Occupant distribution
means distribution of occupants
in a vehicle.
Outer d iameter
means the overall diamete r 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 .
Ply
means a layer of rubber-coated
para llel cords.
338
Production options we ight
means the combined weight of
those installed regular product ion
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 ti re
means a pneumatic tire in which
the ply cords that extend to the beads are la id at substantially 90
degrees to the centerline of the
tread.
Recommended inflation
pressure
see ¢ page 33 7, 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
"XL", "xl", "EXTRA LOAD", or "RF"
on the sidewall. ...

Wheels
&,. WARNING
-Do not use steel rims that are 17 inches or larger . Other­
wise, 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
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.
342
-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. 275 Tire 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.
-Have an authorized Audi dealer or authorized Audi Service Facili­
ty check the wheel alignment if
there is unusual wear .
-Have the wheels rebalanced if an
imbalance is causing noticeable
vibration in the steering wheel. If you do not, the tires and other
..

Wheels
are listed on the safety compli­
ance sticker on the driver's side B­ pillar respectively on the front
end of the driver's door.
& 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 .
-Tires on a vehicle that has been overloaded can fail sud ­
denly, including a blowout and
sudden deflation, causing loss of control and a crash .
-Always make sure that the to­ tal load being transported -
including the weight of a trail­
er hitch and the tongue
weight of a loaded trailer -
does not make the vehicle
heavier than the vehicle's
Gross Vehicle Weight Rating.
348
Determining correct load
limit
Use the example below to calcu­
late the total weight of the pas­
sengers and luggage or other
things that you plan to transport so that you can make sure that
your vehicle will not be overload ­
ed.
Steps for Determining Correct Load Limit
1. Locate the statement "THE
COMBINED WEIGHT OF OCCU­
PANTS AND CARGO SHOULD
NEVER EXCEED XXX KG OR XXX
LBS" on your vehicle's placard
(tire inflation pressure label)
¢ page 344, fig. 277.
2. Determine the combined
weight of the driver and pas­ sengers that will be riding in
your vehicle.
3. Subtract the combined weight
of the driver and passengers
from
"XXX" kilograms or "XXX"
pounds shown on the stick­
er ¢ page 344, fig. 2 77.
4. The resulting figure equals the
available amount of cargo and luggage load capacity . For ex­
ample, if the "XXX" amount
equals 1400 lbs. and there will
.,.

a co .... N ,....
N .... 0 0
3 co
wash operator to reduce the risk of acci­dents.
- 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 brak ing effect
may be delayed due to mo isture on the
brake rotors or ice in the w inter . This in­
creases the risk of an acc ident. The brakes
must be d ried fi rst w ith a few careful b rake
applications.
(D Note
- If you wash t he vehicle in an automatic car
wash, yo u m ust fold the exte rior m irrors in
to reduce the risk of damage to the mirrors.
Power folding exte rior m irrors* must on ly
be fo lded in a nd out using the power folding
fu nct ion.
- To reduce the risk of damage to the rims
and tires, compare the width between the
whee ls on your vehi cle w it h t he dis tan ce be­
tween the g uide rai ls in the
car wash.
- To reduce t he risk of damage, compare the
height and width o f you r vehicle wi th the
Ca re and cleaning
height and w idth of the inside of the car
was h.
- T o red uce the risk of pa int damage, do not
was h the vehicle in d irect sun light .
- T o red uce the risk of d am age to the s urf ace,
do not use insect removing sponges, k itche n
sponges or similar items .
- Mat te finish painted veh icle 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 cou ld be damaged
when the stickers or magne ts are re­
moved .
@ For the sake of the environment
Only wash t he vehicle in facilities s pec ially de­
s ign ed for that pu rpose . This will reduce the
r isk of dirty wate r contaminated with oil from
ente ring the sewe r sys tem.
Cleaning and care information
W hen cleani ng and ca ring for individua l vehicle
components, refer to the follow ing tables . The
i n formation contained there is simply recom­
mendations. For quest ions or for components t
h at are not liste d, co n su lt an autho riz ed Au di
dealer or authorized A udi Se rvice Fac ility . Also
fo llow the information found
in ¢ .&. .
Exterior cleaning
Component Situation Solution
Windshield wiper
Deposits c:> page 61, Cleaning the wiper blades
blades
Headlights /
Deposi ts So
ft spo nge wi th a mild so ap sol ution3>
Tail light s
S ensors /
Deposits Sensors: soft cloth w it h solvent-free cleaning solut ion
Camera len ses Camera le nses: soft clot h w ith alcohol-free cleaning solu-
tion
Snow/ice H
and br ush/solvent-free de-icing spray
Wheels Road salt Water
Brake dust Acid-free special cleaning solution
355

Emergency assistance
Emergency assistance
General information
... Park the vehicle as far as possible from moving
traffic in the event of a breakdown. In the event
of a flat tir e, park the vehicle on a level surface .
It you are on a steep hill, be especially careful.
.,. Set the parking brake .
.,. Switch the emergency flashers on .
... Have the passengers exit the vehicle . They
should move to a safe place, for example be­
hind a guard rail.
_& WARNING
Follow the steps given above . This is for your
protection and the for the safety of other driv ­
ers.
Equipment
Vehicle tool kit/tire mobility kit/vehicle
jack
Applies to: vehicles with the vehicle tool kit, tire mobility kit
and veh icle jack
Applies to: sedan
Fig. 278 L uggage compartmen t: vehicle too l kit , ve hicle
j ack, tire mob ility kit an d comp resso r
Applies to: allroad
Fig. 279 Lug gage compa rtmen t: ve hicl e tool kit, v ehicle
j ack, tir e mobil ity k it and comp resso r
360
The vehicle tool kit, vehicle jack, tire mobility kit
and compressor are stored in the luggage com­
partment under the cargo floor cover.
Applies to: sedan
.,. Lift the cargo floor using the plastic handle and
hook the hand le onto the luggage compart­
ment
seal ~ fig. 2 78.
Applies to: allroad
... Remove the cargo floor cover ~ fig. 279 .
Applies to : vehicles with spare tire
... Remove the handle by turning it counter-clock ­
wise and remove the spare tire.
Appl ies to: sedan
.,. Unhook the cargo floor before closing the lug-
gage compartment lid .
Depend ing on vehicle equipment, the vehicle tool
kit, tire mobility kit and compressor may be lo­
cated under another cover that is secured w ith a
handwheel.
Applies to : allroad
On some vehicles, the vehicle tool kit is located
directly under the cargo floor
cover@~ fig. 2 79
behind the rear bench seat.
_& WARNING
Impr oper use of the vehicle jack can cause se­
rious personal injur ies.
- Never use the screw driver hex head to
tighten wheel bolts, since the bolts cannot
attain the necessary tightening torque if you
use the hex head, potentially causing an ac­
cident.
- The factory-supp lied jack is intended only
for your vehicle mode l. Under no circum­
stances should it be used to lift heavy
veh icles or other loads; you risk injuring
yourself.
- Never start the engine when the vehicle is
raised, which cou ld cause an accident.
- Support the vehicle securely with appropri­
ate stands if work is to be performed under­
neath the vehicle; otherwise, there is a po­
tential risk for injury.

-If the t ire is too severely damaged , see an
authorized Aud i dealer or authorized Aud i
Service Facility for assistance .
@ For the sake of the environment
You can give the used tire sealant bottle to an
author ized Audi dealer or authorized A udi
Serv ice Facility for disposal.
@ Tips
Remember to obtain a new bottle of sea lant
from an authorized Audi dea ler or authorized
Audi Service Facility after repair ing a tire.
Replacing a wheel
Preparation
You must complete the preparation before
changing a tire .
.,. Read and follow the important safety precau­
tions ~ page 360 .
.,. Set the parking brake .
Applies to: ve hicles with man ua l transmiss ion
.,. Shift in to 1st gear.
Applies to: ve hicles with automat ic t ra n smi ssio ns
.,. Select the P selector leve r pos ition .
.,. When towing a trailer: disconnect the tra iler
from your veh icle .
.,. Lay out the veh icle tool kit 9 page 360 and the
spare
tire ~ page 367 .
.,. Switch the ignition off .
A WARNING
When using the vehicle jack* on a road with a
steep hill or offroad, you must take extra pre­
cautions to prevent the vehicle from rolling .
Use suitab le objects to b lock the front and
back of the wheel that is diagonal from the
wheel with the flat tire.
A WARNING
You or your passengers could be in ju red wh ile
chang ing a wheel if you do not follow these
safety precautions :
Emergen cy a ssis tanc e
-If you have a flat tire, move a safe distance
off the road. Turn off the eng ine, turn the
emergency flashers on and use other warn­
ing dev ices to alert other motorists .
- Make sure that passengers wait in a safe
place away from the vehicle and well away
from the road and traff ic .
- To help prevent the veh icle from moving
suddenly a nd possib ly slipping off the jack*,
always fully set the park ing brake and block
the front and back of the wheel diagonally opposite the wheel being changed. When
one front wheel is lif ted off the gro und,
p la cing the Automa tic Transmission in P
(Park) will
not prevent the vehicle from
moving.
- Before you change a wheel, be sure the
g ro und is leve l and firm. If necessary, use a
sturdy board under the jack *.
- Always store the vehicle tool kit, the jack *
a nd the replaced tire in the luggage com­
partment
~ page 259 .
(D Tips
Obey all laws .
Removing the caps
Fig. 283 W hee l: whee l bolt s w ith ca ps
.,. Slide the p lastic clip (from the veh icle tool k it)
on to the cap unt il it
engages ~ fig. 283.
.,. Remove the cap with the p lastic clip.
363

Emergency assistance
CJ) Note
When removing or installing the whee l, the
r im could hit the brake rotor and damage the
rotor. Work ca ref ull y and have a second pe r­
son help you.
@ Tips
- When mounting tires w ith unidirectional
tread design
ma ke s ure the t read pattern is
po inted the r ight
way ¢ page 366.
-The wheel bolts should be clean and easy to
turn. Check for d irt and cor ros ion on the
mating s urfaces of both the wheel and the
h ub. Remove all dirt from t hese surfaces be­
fo re re mo unt ing th e wheel.
Unidirectional tires
A unid irec tional tire p rofile is ident ified by a rrows
th at poin t in the run nin g dir e cti on o n the tire
sidewall. You mus t always a dhere to the speci ­
fied running d irec tion. This is necessary ens ure
the t ire's optim um perfo rmance in regar d to a d­
hes ion, r unning noise, fr iction and hydrop la ning.
T o be nefi t fu lly fro m the adv ant ages of the uni­
d irect ional tire des ign, you sho uld replace faulty
tires as soon as possi ble an d restore the correct
r u nning di rect io n on all of the tires.
Finishing
.,. Reinstall the caps on the whee l bolts if neces­
sary .
.,. Store the vehicle tool kit in its designated
place .
.,. If the re m oved whee l does not fi t in the spa re
whee l we ll, store it se cur ely in t he luggage
com partmen t¢ page 2 59.
.,. Check the tire press ure on the ins talled whee l
as soon as possible.
.,. Co rrect the tire p ressure and store it in the I n­
fota inment system
¢ page 353 .
.,. The wheel bo lt tightening specification must be
90 ft lbs (120 Nm) . Check it as soon as poss ible
with a torq ue wrenc h. Dr ive ca refully unt il t hen .
.,. Have th e faulty wheel rep laced as quic kly as
poss ible.
366
(D Tips
-If you not ice that t he w heel bo lts a re cor­
rode d and difficult to tur n while changing a
t ir e, t hey s hou ld be replaced befo re yo u
check the t ightening torque.
- Drive at red uce d speed unti l yo u have the
t ightening to rques checked.
· Notes on wheel changing
Please read t he informat ion¢ page 341 if yo u
are going to use a replacemen t tire which is d if­
ferent from the tires on yo ur vehicle .
After you change a tire:
- Check the tire pressure on the replacement
tire immediately after installation.
- Have the wheel bolt tightening torque
checked with a torque wrench as soon as pos­
sible by your authorized Audi dealer or quali­
fied workshop.
- With steel and alloy wheel rims, the wheel
bolts are cor rectly tightened at a torque of
90
ft lbs (120 Nm) .
- If you notice that the wheel bolts are corroded
and difficult to turn while changing a tire,
they should be replaced before you check the
tightening torque .
- Replace the flat tire with a new one and have
it installed on your vehicle as soon as possi ­
ble. Remount the wheel cover .
Until then, dr ive with e xtra care and at reduced
speeds.
A WARNING
- If you are going to equip yo ur vehicle wi th
t ires or r ims which diffe r from those which
we re fac to ry insta lled , th en be su re to read
t he
informa tion ¢ page 341.
- Always make sure the damage d w heel or
ev en a fla t tire and the jack* an d tool kit are
p ro p erl y se cured in t he lug gage com part ­
me nt an d ar e no t lo o se in the pas senge r
c o mp artme nt.
- I n an ac cident or su dde n man euver they
co uld fl y forw ard , injur ing an yone i n t he ve ­
hicle.

a co .... N ,....
N .... 0 0
3 co
Fuse panel @ (brown)
No . Equipment
2
Mass airflow sensor, camshaft adjust-
ment, charge air cooler pump
3 Exhaust doors, fuel injectors, radiator inlet
4 Vacuum pump, hot water pump, particu-
late sensor, biodiesel sensor
5 Brake light sensor
6 Engine va lves, camshaft adjustment
7
Heated oxygen sensor, mass airflow sen-
sor
8
Water pump, high pressure pump, high
pressure regulator va lve
9 Hot water pump
10
Oil pressure sensor, oil temperature sen-
sor
11 Clutch pedal position sensor
12 Engine valves
13 Radiator fan
14 Fuel injectors
15 Ignition coils
16 Fuel pump
Fuse panel @ (red)
No . Equipment
1 Anti-theft alarm system
2 Eng ine control module
3 Lumbar support
Automatic transmission selector mecha -
4
nism
5 Horn
6 Electromechanical park ing brake
7 Gateway control module
8 Interior headliner lights
10 Airbag control module
11 Electronic Stabilization Control (ESC)
12 Diagnostic connector, light/rain sensor
13 Climate control system
14 Right front door control module
15 A/C compressor
Fuses and bulbs
Fuse panel © (black)
No . Equipment
1 Front seat heating
2 Windshield wipers
3 Left head light electronics
4
Panorama glass roof I sliding/t ilting sun-
roof
5 L eft front door control module
6 Sockets
7 Right rear door control module
8 All wheel drive
9 Right headlight electronics
10
Windshield washer system/headlight
washer system
11 Left rear door control module
Fuse panel @ (black)
No. Equipment
Seat ventilation, rearv iew mirror, climate
1 control system, rear climate control sys-
tern controls, windshield defogger
2 Gateway, climate control system
3 Sound actuator/exhaust sound tuning
4 Clutch pedal posit ion sensor
5 Engine start
7 Rear USB charg ing port
8 Homelink
9 Adaptive cruise contro l
11 Video camera
12 Matrix LED headlight/right LED headlight
13 Matrix LED headlight/left LED headlight
14 Rear window wipe r
Fuse panel © (red)
No . Equipment
1 Ignition coils
5 En gine mount
6 Automat ic transmission
7 Instrument panel
8 Climate control system (blower)
10 Dynamic steering
11 Engine start
371

@ Tips
The discharged battery must be properly con­
nected to the vehicle's electrical system .
When jump starting or charg ing the battery,
never connect the negative ground cable to
the battery negative post because the battery
manager system must be able to detect the
battery's state of charge. Always connect the
negative ground cable to the negative ground
post of the battery manager control unit.
Using the jump start
cable
Both jump start cables must be connected in the
correct order!
Fig. 295 Engine compartment: connec tors for jump start
cables and a charger
Fig. 296 Ju mp starting us ing a battery in another vehicle:
@ -providing current, @-drained
The procedure described below for connecting
jumper cables is intended to prov ide a jump start
for your vehicle .
Vehicle with discharged battery
•Turnoff lights and accessories, move the auto­
matic transmission* selecto r lever to N (Neu­
tral) or P (Par k), and set the park ing brake.
Emergency situations
Connecting the positive cable (red) to the
positive terminal
• Open the red cover on the positive terminal
c:>fig. 295 .
1. Secure one end of the positive cable (red) to
the jump start pin
c:> fig. 296 (D (pin under
the red cover = "posit ive") on the vehicle that
needs to be started @.
2. Secure the other end of the positive cable
(red) to the positive termina l@ on the
bat­
tery provid ing the current @.
Connecting the negative cable (black) to the
negative terminal
3. Secure one end of the negative cable (black)
to the nega tive term inal @ on the battery
that is providing the current @.
4. Secure the other end of the negative cable
(black) to the jump start
pin @ (hex head pin
= "negative") on the vehicle that needs to be
started @.
Starting the engine
• Start the engine on the vehicle providing the
jump start @and let it run at idle.
• Now start the engine on the vehicle with the
drained battery @.
• If the engine does not start, stop the starting
procedure after 10 seconds and then repeat it
after approx imately 30 seconds.
• Remove the cables when the engines are run­
ning. Remove them in reverse order from the
way they were installed.
• Close the red cover on the positive terminal.
T he battery is vented to the outside to prevent
gases from enter ing the vehicle interior . Make
sure that the jumper clamps are well connected
with their
metal parts in full contact with the
battery terminals.
_& WARNING
-To avoid serious personal injury and damage to the vehicle, heed all warnings and instruc ­
tions of the jumper cable manufacturer. If in
doubt, call for road service.
-Jumper cables must be long enough so that
the vehicles do not touch .
..,_
375