This sounds like a more detailed repeat of your previous post.
If you have an expansion valve, install a liquid line sight glass and charge just enough refrigerant to clear the sight glass of bubbles.

How can a system for a passenger car have a volume of 120 Liters?

If the ambient temperature is 50 F., why do you need A/C ?

Ester oil should not be exposed to moisture or air. If it has been, it should be changed.

Good luck!