not cold

I used my A/C for the first time the other day and it was not cold enough. Roasting in the truck and it was only 80 degrees outside. I'm not excited for when it hits 100 degrees in a couple of months. Where would I begin to diagnose the problem? Plenty of air flow - just not cold enough.

I bought/installed a new compressor, condenser, expansion valve, and the pipes which run from the compressor. The radiator is full and external tank is at proper level - also don't see any obvious leaks. Any ideas why my air wouldn't be blowing cold?