Your system should not be ruined. Most all A/C systems have one
componet that is perishable when open to the atmosphere. Your receiver/drier has desicant material inside of it. It's purpose is to
absorb moisture and keep the system "dry". Most techs replace it when servicing the A/C, however I've found if you allow the system to stand at vacuum on a pump for about 1 1/2 hours you should be ok.