Note: Removal and installation of auxiliary/additional heater and 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 auxiliary/auxiliary heater or circulation pump. However, if the amount of coolant is significantly reduced as a result of another malfunction, e.g. due to a leak in a hose or after replacing the coolant pipes, the coolant circuit must be bled. After bleeding and filling the cooling system, the air must be bled from the auxiliary heater.
Carefully! The coolant circulation pump -V55- must be topped up, as the operation «dry» the pump may be damaged.
Fill coolant expansion tank up to upper mark. Connect tester and switch on circulation pump -V55- in "Guided fault finding" mode", function ''Diagnostics of final elements''. This will additionally bleed the coolant circuit of the heat exchanger in the heating and air conditioning system to the circulation pump -V55-. Start the engine and set the maximum possible temperature on the control and display panels for heating and air conditioning "HI" (in the case of Climatronic, on the driver and front passenger side). Leave the auxiliary/auxiliary heater running at full load for at least 2 minutes (circulation pump -V55- starts). Let the engine run at high idle for at least 2 minutes (approx. 2000-2500 1/min). Switch off the engine and auxiliary/auxiliary heater.
Attention! 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 top up coolant level.