brake MERCEDES-BENZ SL550 2008 R230 Workshop Manual

233 Controls in detail
Driving systems
Suspension for sporty driving style
The setting for sporty driving is selected
when indicator lamp2 is on.
Press button1.
Indicator lamp2 comes on.
Suspension for regular driving style
The setting for regular driving is selected
when indicator lamp2 is off.
Press button1.
Indicator lamp2 goes out.
Parktronic system* (Parking assist)
The Parktronic system is an electronic aid
with ultrasonic sensors. It is designed to
assist the driver during parking maneu-
vers. It visually and audibly indicates the
relative distance between the vehicle and
an obstacle.
The Parktronic system is automatically
activated when you switch on the ignition,
release the parking brake, or place the
gear selector lever in position D, R, or N.
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.
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 337).
Warning!G
Make sure no persons or animals are in the
area in which you are maneuvering. Other-
wise you run the risk of causing injury.
!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.

234 Controls in detail
Driving systems
The Parktronic system deactivates at
speeds exceeding approximately
11 mph (18 km/h). At lower vehicle
speeds the Parktronic system turns on
again. The Parktronic system also deacti-
vates when you place the gear selector le-
ver in position P or depress the parking
brake pedal.
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 bumperRange of the sensorsFront sensors
Rear sensorsiTo 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” (
page 337).
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.

236 Controls in detail
Driving systems
As your vehicle approaches an object, one
or more distance segments will illuminate,
depending on the distance. When the
eighth distance segment illuminates, you
have reached the minimum distance.

Front area: An intermittent acoustic
warning will sound as the first red
distance segment illuminates and a
constant acoustic warning lasting a
maximum of 2 seconds will sound for
the second distance segment.
The signal is canceled when the gear
selector lever is placed in position P or
the parking brake is set.

Rear area: An intermittent acoustic
warning will sound when the first dis-
tance segment illuminates. This signal
quickens with each additional distance
segment lit. When the eighth distance
segment illuminates, the acoustic
warning becomes a constant signal.
The signal is canceled when the gear
selector lever is placed in positionD
orP or the parking brake is set.Switching the Parktronic system
on/off
You can switch off the Parktronic system
manually.
The Parktronic switch is located in the
lower part of the center console.
1Parktronic switch
2Indicator lamp
Switching off
Press Parktronic switch1.
Indicator lamp2 comes on.Switching on
Press Parktronic switch1 once more.
Indicator lamp2 goes out.
Parktronic system malfunction
If only the red distance segments illumi-
nate and an acoustic warning sounds,
there is a malfunction in the Parktronic
system. The Parktronic system will auto-
matically switch off after 20 seconds and
the indicator lamp in the Parktronic switch
comes on.
Have the Parktronic system checked
by an authorized Mercedes-Benz
Center as soon as possible.
iThe Parktronic system switches on automat-
ically when you switch on the ignition
(
page 40).

244 Controls in detail
Useful features
Ashtray
1Cover plate
2Sliding knob
Opening ashtray
Briefly touch cover plate1.
The ashtray opens automatically.
Closing ashtray
Press cover plate1 down until it
latches.Removing the ashtray insert
Secure vehicle from movement by set-
ting the parking brake.
Move the gear selector lever to
positionN.
Now you have more room to take out
the insert.
Press sliding knob2 to the right.
The insert will eject a short distance.
Replacing the ashtray insert
Press the insert into the frame until it
snaps into place.
Cigarette lighter
Switch on the ignition (page 40).
Warning!G
Remove ashtray only with vehicle standing
still. Set the parking brake to secure vehicle
from movement. Move gear selector lever to
positionN. With gear selector lever in
positionN, turn off the engine.
Warning!G
Never touch the heating element or sides of
the lighter; they are extremely hot. Hold the
knob only.
Make sure that any children traveling with
you do not injure themselves or start a fire
with the hot cigarette lighter.
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children
unattended in the vehicle, or with access to
an unlocked vehicle. A child’s unsupervised
access to a vehicle could result in an
accident and/or serious personal injury.

268 Operation
Driving instructions
Power assistanceBrakes
Warning!G
The brake system requires electrical energy
for operation.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 345) and
warning messages (
page 359) in the in-
strument cluster come on while driving. To
brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected braking effect. If necessary, apply
full pressure to the brake pedal. Brakes are
only applied to the front wheels. Stopping
distance is increased! If there is a malfunc-
tion in the electro-hydraulic brake system,
we recommend that the vehicle be trans-
ported with all wheels off the ground using
flatbed or appropriate wheel lift/dolly equip-
ment.
A tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
up to 30 miles (50 km) and at a speed not to
exceed 30 mph (50 km/h). For more infor-
mation, see “Towing the vehicle”
(
page 434).
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
vehicle.
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
effect. 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
accident.

269 Operation
Driving instructions
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
subjected to moderate loads, you should
occasionally 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 91).
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the
reservoir.
The brake fluid level in the reservoir may
be too low or the electro-hydraulic brake
system may be malfunctioning if the brake
warning lamp in the instrument cluster
comes on and an acoustic warning sounds
although the parking brake is released
(
page 345).
Observe additional messages in the
multifunction display that may appear, see
(
page 377) through (page 382).
Have the brake system inspected immedi-
ately. 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
recommended by Mercedes-Benz.
!Because the ESP® operates automatically,
the engine must be shut off (SmartKey in starter
switch position 0 or 1or KEYLESS-GO*
start/stop button in position 0 or 1) when the
parking brake is being tested on a brake test
dynamometer.
Active braking action through the ESP
® may
otherwise seriously damage the brake system.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
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.
Be certain to read and observe the warning
notices on brake pad replacement
(
page 96).
!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.

270 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than to park im-
mediately, so the air stream will cool down
the brakes faster.
High-performance brake system
(AMG vehicles only)
The high-performance brake system is de-
signed to operate under the extremely high
operating demands required to accommo-
date the performance capabilities of the
vehicle. The brakes may produce a squeak-
ing-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 disks 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.
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 smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.
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. Especial-
ly for high performance driving, it is
important to maintain and have the brake
system checked regularly.
!When starting 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 brake reduces engine
performance and causes premature brake and
drivetrain wear.

271 Operation
Driving instructions
ParkingTires
Treadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and be-
come visible at a tread depth of approxi-
mately
1/16in (1.6 mm), at which point the
tire is considered worn and should be re-
placed.
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 drivetrain as a result
of vehicle movement, before turning off the
engine and leaving the vehicle always:

Keep right foot on brake pedal.

Firmly depress parking brake pedal.

Move the gear selector lever to
positionP.

Slowly release brake pedal.

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

Turn the SmartKey or the SmartKey with
KEYLESS-GO* to starter switch
position0 and remove, or press the
KEYLESS-GO* start/stop button.

Take the SmartKey or the SmartKey with
KEYLESS-GO* with you and lock vehicle
when leaving.
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to
the nearest Mercedes-Benz Center or tire
dealer for repairs.

272 Operation
Driving instructions
The treadwear indicator appears as a solid
band across the tread.Specified tire inflation pressures must be
maintained. This applies particularly if the
tires are subjected to extreme operating
conditions (e.g. high speeds, heavy loads,
high ambient temperatures).
For more information, see “Tires and
wheels” (
page 291).
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.
Warning!G
Although the applicable federal motor
vehicle safety laws consider a tire to be
worn when the treadwear indicators (TWI)
become visible at approximately
1/16in (1.6 mm), we recommend that you
do not allow your tires to wear down to
that level. As tread depth approaches
1/8in (3 mm), the adhesion properties on a
wet road are sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
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.

273 Operation
Driving instructions
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 327) 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 as compared with sum-
mer tires. Stopping distance, however, is
still considerably greater than when the
road is not covered with snow or ice. Exer-
cise appropriate caution.
Tire speed rating
Regardless of the tire speed rating, local
speed limits should be obeyed. Use pru-
dent driving speeds appropriate to prevail-
ing conditions.
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.
Warning!G
Even when permitted by law, never operate
a vehicle at speeds greater than the maxi-
mum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire fail-
ure, causing loss of vehicle control and pos-
sibly resulting in an accident and/or
personal injury and possible death, for you
and for others.