Upon arrival custom complaint is no cooling, system is operational upon arrival. Upon inspection there was significant oil around the valve cover, system had little to no refrigerant. After inspection we Proceeded to perform a leak test pressurizing the system, we were able to deuce the leak came from the Schrader core and liquid line flare fitting. Replaced the schrader core and applied nylog onto the suction and liquid line threads. System held pressure. Proceeded to properly vacuum system to below 500 microns. Weighed in 1.7 pounds of R-410A into the system, recharging it. System functioning properly and cooling efficiently upon departure.