[QUOTE=RyanHVAC;16044931] Pump nitrogen in low side, it will hold 110 psi for 2 hours, pump nitrogen in high side to 120psi and will quickly leak down to 80 psi.
If you fill nitrogen on the low side it will go to the evaporator,compressor,out the discharge and onto condenser.
If you fill nitrogen on the high side it will go to the condenser and STOP at the discharge. It will continue to bleed thru the cap tube and fill the evaporator. That is not a external leak but a leak thru the cap tube. Also most restrictions are where your frosting starts. I would do a compressor test.