just got my truck back after a timing belt and valve cover gasket change. My truck used to put frost on the window's, but now its just cool air. Its still cooling some, but now way near as wheel as before. Any idea why this could be, before i call up the mechanic and complain????

Check that the A/C belt is tight. They usually squeal when loose, but maybe it is not squealing for some reason.

I second that the AC belt is too loose and not giving enough power/torque to the compressor....