Using a vacuum pump to leak test the low pressure side of the AC plumbing, making sure that it holds the vacuum "indefinately", which to me would mean 24 to 48 hours, could you also leak test the high pressure side AC plumbing the same way, or would the vacuum have some adverse affect on the expansion valve or other components?
Or does putting the vacuum on the low pressure side open the expansion valve to extend the vacuum to the high side?
Thanks sleepdog