Water Content
WARNING: This page is about a different car, the 2014 Volkswagen Touareg, 2013 Volkswagen Touareg, 2012 Volkswagen Touareg, and 2011 Volkswagen Touareg. However, it is still accessible from the selected car via links, so may be relevant.
Only very small amounts of water are soluble in liquid refrigerant. On the other hand, refrigerant vapor and water vapor mix in any ratio.
A small drop of water may get carried into the refrigerant circuit. The dryer, desiccant bag or dryer cartridge contained in the receiver/dryer or reservoir can absorb approximately 7 grams of water. They are then saturated and cannot absorb any more water. If water is still present in the refrigerant circuit, it flows up to the expansion valve nozzle or restrictor and becomes ice.
The air conditioning system stops cooling.
Water destroys the A/C system, because it forms acids when combined with other contaminants at high pressures and temperatures.