i broke a line right at the service port exposing the entire system to atmosphere. after making a new flare and doing a pressure test on the full system, i did multiple vacuum pulls breaking vacuum with nitro each time. i've cycled vacuum and nitro about 10 times and the last two pulls i let run for 5 hours or so. i have no trouble getting below 100 microns, but when i isolate the system it jumps back up pretty steadily and just seem to keep going. after the last pull it topped 1000 micron at just under 3 hours.
if i close the king valves and just test the line set and indoor unit, it's rock solid. the second graph shows those results.
can anyone interpret these results? i know most of the pros in the field would likely call anything under 1000 microns after an hour good and recharge the system. but after 3 hours of decay i'm still rising a little over 2 microns/minute. i'm assuming that's moisture still in the compressor oil since a leak in the compressor or condenser coil doesn't seem likely.