2008 MERCEDES-BENZ CLK63AMG brakes

268 Controls in detail
Driving systems
1Set current or higher speed
2Set current or lower speed
3Cancel cruise control
4Resume to last set speedSetting current speed
Accelerate or decelerate to the desired
speed.
Briefly lift1 or depress2 the cruise
control lever.
The current speed is set.
Remove your foot from the accelerator
pedal.
Cruise control is activated.
The selected speed appears in the multi-
function display for approximately five sec-
onds, and the corresponding speedometer
segments from the selected speed to the
vehicle maximum speed are illuminated.
Warning!G
Cruise control brakes automatically so that
the set speed is not exceeded. The brake
pedal depresses when the cruise control en-
gages the brakes.
Keep driver’s foot area clear at all times, in-
cluding the area under the brake pedal. Ob-
jects stored in this area may impair pedal
movement which could interfere with the
braking ability of the cruise control system.
Do not place your foot under the brake pedal
- your foot could become caught.
Keep in mind that cruise control is a conve-
nience system designed to assist the driver
during vehicle operation. The driver is and
must always remain responsible for the ve-
hicle’s speed and for safe brake operation.
iOn uphill or downhill grades, cruise control
may not be able to maintain the set speed. Once
the grade eases, the set speed will be resumed.
On downhill grades, the cruise control will hold
the set speed with braking from the vehicle’s
brake system.
In addition, on longer downhill grades the auto-
matic transmission will automatically downshift.

271 Controls in detail
Driving systems
Parktronic system (Parking assist)*,
CLK 63 AMG (USA), Canada all models
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
(
page 38) and placed the gear selector
lever in positionD,R,orN.The Parktronic system deactivates at
speeds over approximately 11 mph
(18 km/h). At lower speeds the Parktronic
system turns on again.
The Parktronic system also deactivates
when you place the gear selector lever in
positionP.
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 bumper
Warning!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 remains with the driver.
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers, car wash,
or the air brakes of trucks) can cause the
system to send erratic indications, and
should be taken into consideration.
!Special attention must be paid to objects
with smooth surfaces or low silhouettes (e.g.
trailer couplings, painted posts, elevated cross-
bars or road curbs). Such objects may not be de-
tected by the system and can damage the
vehicle.
Warning!G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.
!The operational function of the Parktronic
system can be affected by dirty sensors, espe-
cially at times of snow and ice.
Make sure that the area on the bumpers around
the sensors is free of dirt, ice and/or slush, oth-
erwise Parktronic may not function properly, see
“Cleaning the Parktronic system* sensors (CLK
63 AMG (USA), Canada all vehicles)”
(
page 372).

272 Controls in detail
Driving systems
Range 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, see
“Cleaning the Parktronic system* sensors
(CLK 63 AMG (USA), Canada all vehicles)”
(
page 372).
Front sensors
Rear sensorsMinimum distance
If the system detects an obstacle in this
range, all the distance warning segments
illuminate and you hear a warning signal. If
the obstacle is closer than the minimum
distance, the actual distance may no long-
er be indicated by the system.
Centerapprox. 40 in (100 cm)
Cornersapprox. 24 in (60 cm)
Centerapprox. 48 in (120 cm)
Cornersapprox. 32 in (80 cm)
!During parking maneuvers, pay special at-
tention to objects located above or below the
height of the sensors (e.g. planters or trailer
hitches). The Parktronic system will not detect
such objects at close range and damage to your
vehicle or the object may result.
Ultrasonic signals from outside sources (e.g.
truck air brakes, car wash, or jackhammers) may
impair the operation of the Parktronic system.
Centerapprox. 8 in (20 cm)
Cornersapprox. 6 in (15 cm)

310 Operation
Driving instructions
Power assistance
Brakes
To 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.
Refer to the description of the Brake Assist
System (BAS) (
page 92).
Brake pad wear or a leak in the system may
be the reason for low brake fluid level in
the reservoir.
The brake fluid level in the reservoir may
be too low if the brake warning lamp in the
instrument cluster comes on and an
acoustic warning sounds although the
parking brake is released (
page 380).
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
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.
!Because the ESP® operates automatically,
the engine must be shut off (SmartKey in starter
switch position0 or1 or KEYLESS-GO
start/stop button* in position0 or1) when

the parking brake is being tested on a brake
test dynamometer

the vehicle is being towed with the front axle
raised
Active braking action through the ESP
® may oth-
erwise seriously damage the brake system.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.

311 Operation
Driving instructions
Observe additional messages in the multi-
function display that may appear
(
page 404).
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Only install brake pads and brake fluid rec-
ommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream can cool down
the brakes faster.High-performance brake system
(CLK 63 AMG only)
The high-performance brake system is
designed to operate under the extremely
high operating demands required to
accommodate the performance capabili-
ties of the vehicle. The brakes may
produce a squeaking-type noise depending
on the

vehicle speed

brake force applied

ambient conditions, e.g. temperature
and humidity
As with any brake system, the wear of indi-
vidual brake system components such as
brake pads or discs strongly depends on
your driving style and the conditions under
which you operate the vehicle. Thus, a driv-
ing style calling for high demand braking
will cause your vehicle’s brakes to wear
more quickly.
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 prevent overheating of the brakes and
reduces brake pad wear.

312 Operation
Driving instructions
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.Parking
Warning!G
New vehicle brake pads and discs, and
replacement brake pads and discs may take
several hundred miles of driving until they
provide optimum braking efficiency. Until
that time, you may need to use increased
brake pedal pressure while braking. Please
be aware of this and adjust your driving and
braking accordingly during this break-in
period.
Excessive high demand braking will cause
correspondingly high brake wear. Please be
attentive to the brake warning lamp in the
instrument cluster and brake condition mes-
sages in the multifunction display.
Especially for high performance driving, it is
important to maintain and have the brake
system checked regularly.
!When driving off on a slippery surface, do
not allow a drive wheel to spin for an extended
period with the ESP
® switched off. Doing so may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.
!Simultaneously depressing the accelerator
pedal and applying the brakes reduces engine
performance and causes premature brake wear
and drivetrain wear.
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.
To reduce the risk of personal injury, or
damage to the vehicle or the vehicle
drivetrain, as a result of vehicle movement,
always do the following before turning off
the engine and leaving the vehicle:

Keep right foot firmly on brake pedal.

Firmly depress parking brake pedal.

Move the gear selector lever to
positionP.

Slowly release brake pedal.

When parked on an incline, always turn
the front wheels towards the road curb.

314 Operation
Driving instructions
For more information, see “Tires and
wheels” (
page 331).
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 winter tires
(
page 362) 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
appropriate 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.!Avoid spinning of a drive wheel. This may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.

331 Operation
Tires and wheels
Tires and wheels
Contact an authorized Mercedes-Benz
Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and
purchase.Important guidelines

Only use sets of tires and rims of the
same type and make.

Tires must be of the correct size for the
rim.

Break in new tires for approximately
60 miles (100 km) at moderate
speeds.

Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire inflation pressure loss and
damage to the tire beads.

If vehicle is heavily loaded, check tire
inflation pressure and correct as
required.

Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths of less than
1/8in (3 mm).

When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension
components can be damaged.

The operating clearance of the wheels
and the tires may no longer be correct.
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
result in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on re-
treads. The operating safety of the vehicle
cannot be assured when such tires are used.