Page 293 of 506

292 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 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.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 85). 
     
        
        Page 294 of 506

293 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.High-performance brake system 
(CLK 55 AMG 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 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 pre-
vent overheating of the brakes and re-
duces brake pad wear.
Warning!
G
New vehicle brake pads and discs, and re-
placement 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 the brake system and 
have it checked regularly. 
     
        
        Page 358 of 506

357 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
•
The red coolant warning lamp 
comes on when the engine is 
running.
There is insufficient coolant in the reservoir.
Add coolant to prevent engine from 
overheating (
page 310).
If this warning lamp comes on frequently, 
there is a leak in the cooling system.
Have the cooling system checked.
If the coolant level is correct, the electric ra-
diator fan may be broken.
If the coolant temperature is below 
257 °F (125 °C), you can continue 
driving to the nearest authorized 
Mercedes-Benz Center.
Avoid high engine loads (e.g. driving 
uphill) and stop-and-go driving.
•
The red coolant warning lamp 
comes on while driving and you 
hear a warning sound.
The coolant temperature has exceeded 
257 °F (125 °C).
Stop as soon as possible and allow 
the engine and coolant to cool down.
Warning!
G
Driving when your engine is badly overheat-
ed 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 and can occur just by opening 
the hood. Stay away from the engine if you 
see or hear steam coming from it.
Turn off the engine, get out of the vehicle 
and do not stand near the vehicle until the 
engine has cooled down.