64 12... Flushing cooling system when replacing latent heat accumulator due to salt leaks

If a leaking latent heat accumulator has caused a salt solution to enter the coolant circuit, the latter must be flushed as follows:

1. Drain off coolant completely.
2. Replace latent heat accumulator.
   CAUTION: Do not leave salt-saturated mains water in cooling system for longer than absolutely necessary.
3. Add mains water (without radiator antifreeze) and vent latent heat accumulator.
4. Check whether there is a through-flow while venting the heater circuit. If the heating hoses are blocked by salt, interrupt this venting operation and continue to vent the engine circuit. In so doing, set both temperature controllers to max. heating. Then run the engine up to operating temperature until the thermostat opens and the radiator is hot. In this phase, the salt dissolves in the water until the saturation point is reached. Switch off engine and allow to cool. This cooling procedure is accelerated by activating the residual heat program. This program uses the engine's residual heat to heat the passenger compartment. The program is activated when the ignition is turned on. Set fan to maximum speed, open all vehicle doors and switch off recirculated-air or automatic recirculated-air control mode. Here the valve unit of the latent heat accumulator is activated in such a way that the cooling water from the engine circuit is first directed through the heating heat exchanger and cooled down to 45°. This process can be monitored with the MoDiC or Diagnosis and Information System. Below this engine temperature, the process can be terminated because the valve unit switches over and uses the energy from the latent heat accumulator in order to continue heating the passenger compartment. During the cooling-down phase, connect a battery charger to prevent the battery from discharging.
5. Drain off the salt-saturated mains water completely.
6. Add fresh coolant and vent cooling system.
7. Drain off coolant again completely.
8. To conclude, add fresh coolant and vent cooling system.