Bleeding Cooling System & Checking For Water Leaks

Venting cooling system and checking for leaks (S54)

Warning: Danger of scalding!
Open sealing cap only after engine has cooled down.


No vent plugs on radiator and thermostat housing.
The cooling system is vented during the filling procedure.

Note: The vent plug on the radiator feed connection must not be opened for venting.

Before filling, turn on ignition. Set heating controller to max. temperature. Set blower to low level. In this way, the heater valves are opened and the auxiliary delivery pump fitted if necessary operates.

Perform filling operation slowly.
Top up coolant until fill level indicator in expansion tank is at top edge.
Seal off expansion tank.
Allow engine to warm up until thermostat opens.
Allow car to cool down until coolant temperature drops below 30°C.
Open sealing cap on expansion tank slowly in order to gradually reduce residual pressure.






Correct fill level until fill level indicator is at top edge of expansion tank.

Note: Use only recommended coolant.

Check cooling system for leaks.