How was it pulling down when you evacuated it? Did you check the compressor shaft seal?
I usually pressure test my systems with nitrogen. For the average guy to do that you'd have to invest in a nitrogen regulator and cylinder, commonly available at commercial HVAC suppliers such as R E Michel's and Aireco, etc.
Suction pressure should be in the 30-42 psi range, and anything under 30 psi could result in evaporator icing. Discharge pressure is a bit subjective, depends on load and outdoor ambient. The FSM has an excellent section in the back for checking load. To do it like a pro you need to know the humidity, aka wet bulb temp for old timers.
