I dealing with a compressor to cool a production area.It has 3 low velosity blowers.It has a big leak.I thought it must be in a blower. I pumped down. Pumped in nitro. I got pressures up to 350 pounds. Thinking i would hear leak in one of blowers. I am charging a drum of r22 every week. I didnt hear anything from blowers. I seen oil leaking out of compressor plate on bottom of compressor under oil glass. I don't see that being my leak, it should be a leak in high side. I don't see any leaks in the sloinoid or exspanion valves. I vacuumed for 2 1/2 hours. opened high side valve to start compressor. low side read 45 lbs. high side 325.It was 85 degrees ambiant temp. high side should been must lower because it way under charged. Has I was charging the high side kept kicking ouy on high temp. I pressure was condensor coil. It is still kicking out on high temp. Did I let nitro in system. Please help!!!!!