79 Safety and Security
Driving safety systems
The SBC brake servo assistance switches
off automatically when you:
turn the key in the starter switch to
position0 or remove the key (after ap-
proximately two minutes)
lock the vehicle with the SmartKey
from outside (after approximately
20 seconds)
Note on driving with the SBC
Following extended periods of only mi-
nor loads to your brake system, you
should occasionally apply the brakes
when traveling at high speeds. This im-
proves the grip of the brake pads.
iIf the SBC brake system is activated
when the brake pedal is first de-
pressed, you may feel a reduced pedal
resistance and longer pedal travel than
normal. When releasing the pedal, you
may also feel the brake pedal pulsate
and you may hear a sound which is
caused by the activation of the SBC
pump. This is normal and not an indica-
tion of a malfunction. Pedal travel re-
turns to normal when you release the
brake pedal and the sound soon ceas-
es.
Warning!
G
Have brake pad replacement and other work
on the SBC brake system carried out by
qualified technicians only. Contact your au-
thorized Mercedes-Benz Center for further
information. The SBC brake system must be
deactivated prior to working on the system.
High pressure is intermittently built up in the
system as part of its automatic self-test. In
addition, the system is automatically acti-
vated when the vehicle is unlocked by re-
mote control, when the driver or passenger
door is opened, when the key in the starter
switch is turned to position1, when the
brake pedal is depressed or when the park-
ing brake is released. Failure to deactivate
the system prior to maintenance will cause
brake pistons to extend and brake fluid to
leak, which may result in injuries (contu-
sions and acid burns). Extended brake pis-
tons may also cause injury.
Warning!
G
Be very careful not to endanger other road
users when you apply the brakes.
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251 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 sub-
jected 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, there is a malfunction in the
SBC brake system (
page 77) or the
brake fluid level in the reservoir 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 at an au-
thorized Mercedes-Benz Center immedi-
ately.
All checks and service work on the brake
system should be carried out by an autho-
rized 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
parking, so that the air stream will cool
down the brakes faster.
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 74).
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 305).!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.
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