Arrived upon no cooling call, and found the following. 2ton r22 condenser with little to no pressure. Figured it had a leak, so I recharged the system. Checked some obvious locations and found nothing. Told the homeowner to call if they lost their cooling, otherwise id go through the system next spring. Returned today, after getting the call, and found the following. Low charge again, but my pressures were reading roughly 125 on the high and 0 on the low. So I valved off the high side, and watched the high side drop to zero and the low remain at 0. Then I valved off the condenser, and added gas through the high side and watched It come right around to the low. This confirmed no restrictions in the piping, filter drier, or evaporator. So im figuring, I have a restriction in my condenser coil. Now im scratching my head for two reasons. 1 wouldn't I have seen pressure on my low side when I valved off my high side and my high side pressure dropped to zero. In other words, if I had pressure in my liquid line wouldn't it have come around when it was pumping down. And 2 where does my refrigerant keep going? Out a compressor relief valve from the pressure getting too high because of a restriction in my coil. I don't feel my compressor valves are bad because I have a pressure differential. Any insight or opinions Is appreciated thx