2004 MERCEDES-BENZ CLK55AMG CABRIOLET brakes

241 Controls in detail
Driving systems
Parktronic (Parking assist)*
The Parktronic system is an electronic aid
designed to assist the driver during park-
ing maneuvers. It visually and audibly indi-
cates the relative distance between the
vehicle and an obstacle.
The Parktronic system is automatically ac-
tivated when you switch on the ignition
and release the parking brake. The Park-
tronic system deactivates at speeds over
approximately 11 mph (18 km/h). At low-
er speeds the Parktronic system turns on
again.The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumperWarning!
G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always rests with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors, es-
pecially at times of snow and ice, see
“Cleaning the Parktronic* system sensors”
(page 308).
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers or the air
brakes of trucks) can cause the system to
send erratic indications, and should be tak-
en into consideration.
Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.

242 Controls in detailDriving systemsRange of the sensors
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the
sensors regularly, being careful not to
scratch or damage the sensors.Front sensors
Rear sensors
Minimum distance
If the system encounters an obstacle in
this range, all the warning lamps come on
and you hear a warning signal. If the obsta-
cle is closer than the minimum distance,
the actual distance may no longer be indi-
cated by the system.
Center
approx. 39 in (100 cm)
Corners
approx. 23,5 in (60 cm)
Center
approx. 47 in (120 cm)
Corners
approx. 32 in (80 cm)
!During parking maneuvers, pay special
attention to objects located above or
below the height of the sensors (e.g.
planters or trailer hitches). The Park-
tronic system will not detect such ob-
jects at close range and damage to
your vehicle or the object may result.
Ultrasonic signals from outside sourc-
es (e.g. truck air brakes or jackham-
mers) may impair the operation of the
Parktronic system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)

274 OperationDriving instructionsBrakesTo help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
ject to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on, the brake fluid level in the res-
ervoir is too low.
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the res-
ervoir.
Have the brake system inspected immedi-
ately. Contact your authorized
Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact your authorized
Mercedes-Benz Center.
Only install brake pads and brake fluid rec-
ommended by Mercedes-Benz.Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking ef-
fect. Maintain a safe distance from vehicles
in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
!Be very careful not to endanger other
road users when you apply the brakes.
Refer to the description of the Brake
Assist System (BAS) (
page 78).

275 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so that the air stream can cool
down the brakes faster.
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine gradually. Do not
place full load on the engine until the oper-
ating temperature has been reached.
When starting off on a slippery surface, do
not allow a drive wheel to spin for an ex-
tended period. Doing so may cause serious
damage to the drive train which is not cov-
ered by the Mercedes-Benz Limited War-
ranty.
Parking
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.!When driving down long and steep
grades, relieve the load on the brakes
by shifting into a lower gear to use the
engine’s braking power. This helps pre-
vent overheating of the brakes and re-
duces brake pad wear.
!Simultaneously depressing the acceler-
ator pedal and applying the brake re-
duces engine performance and causes
premature brake wear and drivetrain
wear.
!Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
move gear selector lever to positionP.
When parking on hills, turn front wheels
towards the road curb.Warning!
G
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.

277 Operation
Driving instructions
Specified tire pressures must be main-
tained. This applies particularly if the tires
are subject to extreme operating condi-
tions (e.g. high speeds, heavy loads, high
ambient temperatures).Hydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur, even
at low speeds and with new tires. Reduce
vehicle speed, avoid track grooves in the
road and apply brakes cautiously in the
rain.
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.Mercedes-Benz recommends M+S rated
radial-ply tires with a minimum tread depth
of approximately
1/6in (4 mm) on all four
wheels for the winter season to ensure
normal balanced handling characteristics.
On packed snow, they can reduce your
stopping distance compared to summer
tires. Stopping distance, however, is still
considerably greater than when the road is
not covered with snow or ice. Exercise ap-
propriate caution.
Warning!
G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.
Warning!
G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.

296 OperationTires and wheels
Tires and wheelsSee your authorized Mercedes-Benz
Center for information on tested and rec-
ommended rims and tires for summer and
winter operation. They can also offer ad-
vice concerning tire service and purchase.Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and tires is no longer guaran-
teed.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.

316 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
l
The red Distronic indicator lamp
comes on while driving.
You are too close to the vehicle in front of you
to maintain selected speed.

Apply the brakes immediately to in-
crease the following distance.
l
The red Distronic indicator lamp
comes on while driving and you
hear a warning sound.


You are gaining too rapidly on the vehicle
ahead of you.


The distance warning system has recog-
nized a stationary obstacle on your prob-
able line of travel.

Apply the brakes immediately.

Carefully observe the traffic situation.
You may need to brake or maneuver
to avoid hitting an obstacle.
v
The yellow ESP warning lamp
comes on while driving.
The ESP is deactivated.
Risk of accident!
Adapt your speed and driving to the prevail-
ing road conditions.

Switch the ESP back on (
page 81).
If the ESP cannot be switched back on,
have the system checked at an autho-
rized Mercedes-Benz Center as soon as
possible.

347 Practical hints
Where will I find...?
In the case of a flat tire, you may tempo-
rarily use the Minispare wheel when ob-
serving the following restrictions:

Do not exceed a vehicle speed of
50 mph (80 km/h).


Drive to the nearest tire repair facility
to have the flat tire repaired or re-
placed as appropriate.


Do not operate vehicle with more than
one Minispare wheel mounted.
More information can be found in the
“Technical data” section (
page 403).
Minispare wheel bolts
1Wheel bolt for light alloy rims
2Wheel bolt for Minispare wheel or other
steel rims (located in trunk with spare
wheel)
!To prevent damage, always disengage
trunk floor handle from upper edge of
trunk and lower trunk floor before clos-
ing the trunk lid.Warning!
G
The dimensions of the Minispare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a Minispare wheel
mounted.
The Minispare wheel should only be used
temporarily, and should be replaced with a
regular road wheel as quickly as possible.
!Wheel bolts2 must be used when
mounting the Minispare wheel. The use
of any wheel bolts other than wheel
bolts2 for the Minispare will physical-
ly damage the vehicle's brakes.Warning!
G
Make sure to use the original length wheel
bolts when remounting the original wheel af-
ter it has been repaired.