2008 Mercedes SL-Class Owner's Manual - Page 289

Operation Engine compartment Coolant Warning! 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 below 158°F (70°C) The coolant expansion tank is located on the passenger side of the engine compartment. G In order to avoid any 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 gauge indicates that the coolant is overheated. Do not remove pressure cap on coolant reservoir if coolant temperature is above 158°F (70°C). Allow engine to cool down before removing cap. The coolant reservoir contains hot fluid and is under pressure. Using a rag, slowly open the 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. 1 Coolant expansion tank Using a rag, slowly turn the cap approximately one half turn counterclockwise to release any excess pressure. Continue turning the cap counterclockwise and remove it. 288