hello i have the same proble with a similar equipment, i resolver drop the vacuum to 100 micron in the 3rd stage, the ? if how is very easy floch the sistem wiht R-11 if ni have using a "Electra" is a solver and good trap moisture, and using the prosedure triple evacuating using cleand nitogen, remember in this equipment the most litter particular of moisture if the big problems,conect a light bult 100 watt front the evaporator you remember me good luck........