Note: The removal and installation of the independent/additional heater and the circulation pump "V65" is described in such a way that only a small amount of air enters or remains in the coolant circuit. Therefore, it is not necessary to bleed the entire coolant circuit after removing and installing the independent/additional heater or the circulation pump. However, if the amount of coolant has decreased significantly due to another fault, e.g. a leaky hose or after replacing the cooling system pipes, the coolant circuit must be bled. After bleeding and filling the cooling system, the independent heater must be bled.
Caution! It is necessary to fill the circulation pump "V55" with coolant, since the pump may be damaged as a result of running "dry".
Fill the expansion tank of the cooling system with coolant to the upper mark. Connect the Tester and switch on the circulation pump "V55" in the "Guided fault finding" mode, "Diagnostics of actuators" function. This will additionally remove air from the coolant circulation circuit of the heat exchanger in the heating and air conditioning system to the circulation pump "V55". Start the engine and set the highest possible temperature "HI" on the control panel and display of the heating, air conditioning system (in the case of Climatronic - on the driver's and front passenger sides). Leave the independent / additional heater to operate at full load for at least 2 minutes (the circulation pump "V55" starts). Leave the engine to run at an increased idle speed for at least 2 minutes (approx. 2000-2500 1/min). Switch off the engine and auxiliary/auxiliary heater.
Warning! Risk of burns from hot steam or hot coolant. The cooling system is under pressure. The coolant temperature of a warm engine may exceed 90°C.
Check and bring the coolant level up to normal.