[Ncgreasemonkey]

Did your friend test with Ac gauges? It sounds like either low freon (I.E. leak as you first suspected) or it could be a restriction in the system. (Restriction causing the high side to go way too high and high pressure switch cutting out). If there's a restriction, it isn't gonna be cheap, so be sure that's the case. (with a restriction the only way to eliminate it is to replace orfice tube/expansion valve (depending on system), and the accumulator/reciever-dryer that's generally where the stoppage occurs. Since your friend tested it, I assume the clutch was engaging?