Troubleshooting help needed-AC pressures

Find a commercial/industrial HVAC guy and pressure test the system with nitrogen. You should be able to do a 24hr standing pressure test at 200 psi. Sometimes I'll allow a 3-5 psi change to temperature changes over that time. If you have access to a micron gauge, it should evacuate to 200 microns.

CPS VG200 MICRONS, MILLIBAR, TORR and INCHES/HG