2009 MERCEDES-BENZ SLR overheating

89 Safety and Security
Driving safety systems
The electro-hydraulic brake servo assis-
tance switches off automatically

approximately 2 minutes after you
turned the SmartKey in the starter
switch to position0 or removed the
SmartKey


approximately 20 seconds after you
locked the vehicle from the outside
Notes on driving with the
electro-hydraulic brake system


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 and
prevents possible brake noise.


After driving on wet or snow-covered
roads, you should apply your brakes
firmly before parking your vehicle. This
produces heat which serves to dry the
brake disks.


On long and steep grades, shift to a
lower gear (gear range1, 2, or 3) to
prevent the brakes from overheating
and to reduce brake wear. If you need
to brake, do not keep the brake pedal
depressed, instead depress it repeat-
edly in short intervals.


After hard braking, it is advisable to
drive on for some time so that the air
stream will cool down the brakes
faster.


Only Mercedes-Benz approved compo-
nents (e.g. brake pads) should be
installed on your vehicle. Brake pads
not approved by Mercedes-Benz may
impair the safety of your vehicle.
Warning!
G
Have brake pad replacement and other work
on the electro-hydraulic brake system car-
ried out by qualified technicians only. Con-
tact an authorized Mercedes-Benz Center
for further information. The electro-hydrau-
lic 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 activated when the
vehicle is unlocked by remote control, when
the driver or passenger door is opened,
when the SmartKey in the starter switch is
turned to position1, when the brake pedal
is depressed or when the parking brake is
released. Failure to deactivate the system
prior to maintenance will cause brake pis-
tons to extend and brake fluid to leak, which
may result in injuries (contusions and acid
burns). Extended brake pistons may also
cause injury.
Warning!
G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.

237 Operation
Driving instructions
Downhill grades
Continuous or hard braking
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.Wet roads
The first time the brakes are applied after
a long period of driving in heavy rain with-
out braking, it is possible that:


there will be a delayed braking re-
sponse


you will need to depress the brake ped-
al more firmly
You should therefore maintain a greater
distance from the vehicle in front.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.
Salty roads
!
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.
Warning!
G
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 or in the total loss of braking per-
formance. It may not be possible to stop the
vehicle in sufficient time to avoid an
accident.
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.
Warning!
G
A layer of salt on the brake discs and the
brake linings may cause a delay in the brak-
ing effect, resulting in a significantly in-
creased braking distance, which could lead
to an accident.


310 Practical hintsWhat to do if ...
During severe operating conditions, e.g.
stop-and-go traffic, the coolant tempera-
ture may rise close to 248°F (120°C).
Problem
Possible cause/consequence
Suggested solution
D
The red coolant temperature
warning lamp comes on while
the engine is running.
There is insufficient coolant in the reservoir.

Immediately add coolant to prevent en-
gine from overheating (
page 255).
If this warning lamp comes on frequently,
there is a leak in the cooling system.

Have the cooling system checked by
an authorized Mercedes-Benz Center.
If the coolant level is correct, the electric
radiator fan may be broken.

If the coolant temperature is below
248°F (120°C), you can continue driv-
ing to the nearest authorized
Mercedes-Benz Center.

Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.
D
The red coolant temperature
warning lamp comes on while
the engine is running and you
hear a warning sound.
The coolant temperature has exceeded
248°F (120°C).

Stop as soon as possible in a safe loca-
tion and allow the engine and coolant
to cool down.
Warning!
G
Driving when your engine is overheated can
cause some fluids which may have leaked
into the engine compartment to catch fire.
You could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by open-
ing the engine hood. Stay away from the en-
gine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of
the vehicle and do not stand near the vehicle
until the engine has cooled down.
!
The engine should not be operated with the
coolant temperature above 248°F (120°C). Do-
ing so may cause serious engine damage which
is not covered by the Mercedes-Benz Limited
Warranty.

338 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
;
(USA only)
3
(Canada only)
Brakes Overheated
Drive on, but with
even greater care
The brake system is overheated
due to an excessive load on the
brakes.

Relieve the load on the brake system.

Drive more smoothly and think ahead to avoid
unnecessary braking.

Use the engine’s braking power more frequent-
ly. Shift into a lower gear (
page 174).

Cautiously continue driving so that the air
stream will cool down the brakes.

The message disappears after driving carefully
for a few minutes.
Warning!
G
Overheating of the brake system will short-
en the service life of the brake disks. The
brake disks could fail. Have the brake disks
checked at an authorized Mercedes-Benz
Center.