samsung ac split m/n aqv18nsdxkcv trips on low refrigerant in cooling mode with the lowside pulling into a vacum, yes you would think its low on gas but on off cycle equalizing to 150lbs. i really wish there was a high side port but there is not. looks to me like there is no pumpdown solenoid aand the only restrictions could be in the 4way valve (yeah its a heatpump) or the exspansion valve. i hate a/c splits never worked on a samsung anyone out there have aany words of wisdom, it would be much appreciated