Checked the unit and found it low on charge. Leak checked the unit but did not find a leak at this time. Added a stop leak additive and charged the unit with refrigerant. Washed the condenser coils. Found that the liquid pressure is to high. Found a restriction on the liquid line dryer. It is recommended that the dryer be replaced and the system evacuated. 7/17/17 returned recovered the refrigerant, replaced the liquid line dryer. Pressure tested the system. Pulled a deep vacuum ,charge the system with virgin refrigerant. Checked the operation of the unit. The pressures and temperature are normal now. Left the unit cooling to full capacity.