With the Front Crank seal Finished and the A/C System put back together with new O Rings, Evaporator/dryer, and retrofit 134 kit. It was time to see if the system could hold a vacuum which it didn't so I tracked it down to a faulty new O Ring on the Low pressure hose to the Evaporator. I replaced it with a thicker O Ring. After it held Vacuum for 30 min I introduced new oil and refrigerant...Woohoo A/C again !!