Draining and Topping Up Coolant

Draining and topping up coolant

Note: After topping up the coolant and bleed the cooling system, check for water tightness.

Drain coolant

Caution: Danger of scalding!
Safety information: Only perform this work after engine has cooled down.






Separate expansion tank

Unfasten cap on expansion tank.






Integrated expansion tank

Unfasten cap on expansion tank.






Remove front underbody protection and unfasten drain plug at bottom of radiator if necessary.

Installation:

Replace gasket. Tightening Torque, refer to Cooling System - Specifications - Mechanical.
Drain, catch and dispose off coolant.

All 6-cylinder engines






Unfasten drain plug on engine block.

Installation:

Replace gasket.
Tightening Torque, refer to Cooling System - Specifications - Mechanical.
Drain, catch and dispose off coolant.

All 4-cylinder engines






Unfasten drain plug on engine block

Installation:

Replace gasket.
Tightening Torque, refer to Cooling System - Specifications - Mechanical.
Drain, catch and dispose off coolant.

Top up coolant






Separate expansion tank

No bleed screws on radiator and thermostat housing!
All bleeding occurs through the vent pipe which leads to the connection on the expansion tank.
Coolant system is vented during the filling procedure.

Integrated expansion tank






Unfasten vent screw on expansion tank.
All bleeding occurs through vent plug on expansion tank. Cooling system is vented after the filling procedure.

M40






Loosen additional vent screw on thermostat housing

M52






On vehicles with M52 engines, also unfasten additional vent screw.






Note: Before filling, switch on ignition, set heater control to maximum temperature and set fan to low speed. This opens heating valves and installed auxiliary water pump runs if necessary.

Perform filling operation slowly.
Fill expansion tank completely and wait until coolant emerges at vent point(s) without bubbles. Close bleed screw(s).

Note: Only use specified coolant.