225 Coolant level
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hintsCar care Index Adding coolant
If coolant has to be added, a 50/50 mixture of water and 
MB anticorrosion/antifreeze should be added.
Model SL 500
The drain plugs for the cooling system are located on 
the right side of the engine block and at the bottom of 
the radiator. 
Model SL 600
The drain plugs for the cooling system are located on 
the right and left sides of the engine block and at the 
bottom of the radiator. 
Anticorrosion/antifreeze, see coolants on page 281. 
Wa r n i n g !
In order to avoid possible serious burns or injury:
• 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 gauge indicates that the engine is 
overheated.• Do not remove pressure cap on coolant 
reservoir if engine temperature is above 194°F 
(90°C). Allow engine to cool down before 
removing cap. The coolant reservoir contains 
hot fluid and is under pressure.• Using a rag, slowly open cap approximately 1/2 
turn to relieve excess pressure. If opened 
immediately, scalding hot fluid and steam will 
be blown out under pressure.• Do not spill antifreeze on hot engine parts. 
Antifreeze contains ethylene glycol which may 
burn if it comes into contact with hot engine 
parts.