water pump AUDI Q7 2009 Owner´s Manual

The ASR works in conjunction with the ABS. If a malfunction should
occur in the ABS, the ASR wil l also be out of action.
& WARNING
The increased safety afforded by ASR does not mean that you can
take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i ] Tips
To ensure that the ASR works properly, all four wheels must be fitted
with identica l tires. Any differences in rolling radius of the tires can
cause the system to reduce engine power when this is not desired.
See also~
page 359, "New tires and rep lacing tires and wheels". •
Braking
General information
What affects braking efficiency?
Operating conditions and driving habits
The brakes on today's automobiles are still subject to wear,
depending large ly on operating conditions and driving habits~& .
On vehicles that are either driven mostly in stop-and-go city traffic
or are driven hard, the brake pads shou ld be checked by your autho ­
rized Audi dealer more often than specified in the
Warranty & Main­
tenance booklet.
Failure to have your brake pads inspected can
result in reduced brake performance.
On steep slopes, you shou ld use the braking effect of the engine .
This way, you prevent unnecessary wear on the brake system. If you
must use your brakes, do not hold the brakes down continuously.
Pump the brakes at intervals.
Controls and equip­
ment Safety first Vehicle operation
Intelligent technology
Moisture
or road salt
If you are driving faster than 3 1 mph (50 km/h) and the windshield
wipers are on, the brake pads will briefly touch the brake discs in
regular intervals so as to improve reaction time when braking on
wet surfaces. You, the driver, will not notice anything.
Under certain conditions, for example, when driving through water
or very heavy rain, or even after washing your vehicle, the braking
effect can be reduced due to moisture (or in freezing conditions ice)
on the brake pads. A few careful brake applications sho uld dry off
the brake pads or remove any ice coatings .
The effectiveness of the brakes can be reduced when the vehicle is driven on a salt -covered road and the brakes are not used. Here too,
you should clean off accumulated salt coating from brake discs and
pads with a few carefu l app lications of the brake ~& .
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 not driven regularly or
only for short trips with litt le use of the brakes.
If the brakes are not used frequently, or if corrosion has formed on
t he discs, it is advisable to clean off the pads and discs by braking
firm ly a few times from a moderately high speed~&.
Faults in the brake system
If you shou ld notice a sudden increase in brake peda l trave l, then
one of the two brake circuits may have failed~& .
Low brake fluid le vel
Malfunctions can occur in the brake system if the brake fluid level is
too low . The brake fluid level is monitored electronically .
Brake lining wear status
Brake lining wear may be checked by visual inspection of the condi ­
tion of the brake pads through the openings in the wheel. If neces­
sary, the wheel may be removed for this inspection
~ page 373,
"Changing a whee l" . ._.
Vehicle care Do-it-yourself service Technical data

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& WARNING
• You should perform braking maneu vers for the purpose of
cleaning the brake system only if road conditions permit . Other
road u sers mu st not be put at r isk -you may cause an a ccident!
• Before des cending a steep grade, reduce speed and shift trans ­
mission into a lower gear or lower dr iving range . Do not ride the
brakes or hold the pedal down too long or too often. This could
cause the brake s to get hot and diminish braking effi ciency .
• Do not "ride the brakes " by resting your foot on the pedal when
you do not intend to b rake. This may cause the br ake s to ove rheat ,
premature wear and increased stopping distance.
• Under ce rtain climat ic and operating condit ions such as
passing through water , driving in heavy rain or after washing the
vehi cle , the effectiveness of the brakes can be reduced . In winter ,
ice can a ccumulate on the brake pads , linings , discs and drums .
Carefully apply bra kes fo r a test . Brakes will dry and ice coatings
will be cleaned off after a few careful brake appli cations .
• Driving for an extended period of time on salt -co vered roads
without using your brakes can also affect braking effic iency. Clean
off accumulated salt coating from brake dis cs and pads with a few
c areful brake applications .
• If you damage the front spoile r, or if you install a different
spoiler, be sure the air flow to the front brakes is not ob structed.
Otherw ise the brake sy stem could overheat reducing the effective­
ness of the entire brake system .
• Failure of one bra ke cir cuit will impair the braking capability
resulting in an increased stopping distance. Avoid driving the
vehicle and ha ve it towed to the nearest authorized Audi dealer or
qualified workshop . •
Brake booster
T he b rake boost er ad ds extra b ra kin g powe r.
The brake booster works with vacuum pressure which is created
o nly w he n t he e ngine is ru nnin g=> & .
& WARNING
• Never let the vehicle roll to a stop with the engine shut off.
• If the brake booster is not working, for example when towing
your vehicle, or because the brake boo ster has somehow been
damaged , the brake pedal must be pressed considerably harder to
make up for the lack of booster assistance . •
Functioning of A!"lt"-Lock Brake System (ABS)
ABS p revents the wheels from locking up unde r brakin g.
Th e ABS co ntribu tes effect ively to vehicle cont ro l since it preve nts
the whee ls from
locking when the brakes are app lied. This means
t h at the ve hicle rema ins steerable and is less l ikely to s kid.
With ABS you do not need to pump the brake . Just hold the brake
pedal down .
However, do not expec t the A BS to s hor ten bra king d istance u nder
all circumstances. When driving o n grave l or on newly fallen snow
o n t op o f icy sur faces, brak ing d istance may be ev en lon ger, the re­
fore, under these c ircumstances, it is especially important that you
driv e slow ly an d with gre at ca re.
How the ABS system works
An a utomatic c heck is m ade w hen a speed of about 1 2 mph (2 0
km/h) is reached. When this happens, a pumping noise can be
h ea rd.