Volvo looked at AC and said it appears no leaks but freon was 50% off. If the AC is still blowing cool but not cold air, is this the evaporator?
Evaporator on 1999 Volvo S70
For the air conditioning to have lost 50% of its charge the system must have a leak. The evaporator is the most difficult to find the leak in because it is hidden behind the dash. There is a refrigerant available that has a florescent dye in it that leaves dye at the point of the leak making it easier to find the source of the leak if there is actually a leak somewhere.