Page 323 of 521

322 Operation
At the gas station
Check regularly and before a long trip
Engine compartment (CLK 550, example)
1Coolant level
2Brake fluid (fuse box cover removed)
3Windshield washer and headlamp
cleaning system*Coolant
For normal replenishing, use water (pota-
ble water quality). For more information,
see “Coolant” (
page 328) and see “Fu-
els, coolants, lubricants, etc.”
(
page 489).
Brake fluid
Removing fuse box cover,
see (
page 473).Windshield washer and headlamp
cleaning system*
For more information on filling up the
washer reservoir, see “Windshield washer
system and headlamp cleaning system*”
(
page 330).
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 325).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
“Replacing bulbs” (
page 443).
For more information, see “Exterior lamp
switch” (
page 55).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 341).
iOpening the hood, see (page 323).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Center immediately.
Do not add brake fluid as this will not solve the
problem. For more information, see also “Practi-
cal hints” (
page 380).
Page 329 of 521

328 Operation
Engine compartment
Coolant
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking the coolant level,
the vehicle must be parked on level
ground
the coolant temperature must be be-
low 158°F (70°C)
The coolant expansion tank is located on
the passenger side of the engine
compartment.
1Coolant expansion tank
2Cap
Using a rag, turn cap 2 slowly
approximately one half turn counter-
clockwise to release any excess
pressure.
Continue turning the cap 2 counter-
clockwise and remove it.
The coolant level is correct if the level
for cold coolant: reaches the marking
(plastic bridge) inside the reservoir
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap 2.
More information on coolant can be found
in the “Technical data” section
(
page 494).
Warning!G
In order to avoid potentially serious burns:
Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature indicator
indicates that the coolant is overheated.
Do not remove pressure cap on coolant
reservoir if the coolant temperature is
above 158°F (70°C). Allow the coolant
to cool down before removing cap.
The coolant reservoir contains hot fluid
and is under pressure.
Using a rag, slowly open the cap approx-
imately 1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.
Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.
Page 383 of 521

382 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
ú
±(USA only)
(Canada only)
The yellow engine malfunction
indicator lamp comes on while
driving.A loss of pressure has been
detected in the fuel system. The fuel
cap may not be closed properly or
the fuel system may be leaky.Check the fuel cap (page 320).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked at an autho-
rized Mercedes-Benz Center.
•The red coolant warning lamp
comes on when the engine is run-
ning.There is insufficient coolant in the
reservoir.Add coolant to prevent engine from overheat-
ing (
page 328).
If this warning lamp comes on fre-
quently, there is a leak in the cooling
system.Have the cooling system checked.
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 driving to the
nearest authorized Mercedes-Benz Center.
Avoid high engine loads (e.g. driving uphill)
and stop-and-go driving.
Page 497 of 521

496 Technical data
Fuels, coolants, lubricants, etc.
Windshield washer system and
headlamp cleaning system*
Both the windshield washer system and
headlamp cleaning system are supplied
from the windshield washer reservoir.
The windshield washer reservoir has a
capacity of approximately:
3.2 US qt (3.0 l) in vehicles with wind-
shield washer system
6.4 US qt (6.0 l) in vehicles with heated
windshield washer system* and head-
lamp cleaning system*.
Refill the reservoir with MB Windshield
Washer Concentrate “MB SummerFit”
and water (or concentrate and com-
mercially available premixed wind-
shield washer solvent / antifreeze,
depending on ambient temperatures).Windshield and headlamp washer fluid
mixing ratio
For temperatures above freezing point, use
MB Windshield Washer Concentrate
“MB SummerFit” and water:
1 part “MB SummerFit” to 100 parts
water
(1.34 fl oz [40 ml] “MB SummerFit” to
1gal [4.0l] water)
For temperatures below freezing point, use
MB Windshield Washer Concentrate
“MB SummerFit” and commercially avail-
able premixed windshield washer
solvent / antifreeze:
1 part “MB SummerFit” to 100 parts
solvent
(1.34 fl oz [40 ml] “MB SummerFit” to
1 gal [4.0 l] solvent)
Warning!G
Washer solvent/antifreeze is highly flam-
mable. Do not spill washer
solvent/antifreeze on hot engine parts, be-
cause it may ignite and burn. You could be
seriously burned.