[Jim Sims]

If you've drained the compressor, replaced the R/D and flushed the condensers you will surely need to add more than 2 oz of refrigerant mineral oil (for R-12.) You will need a good vacuum pump; the compressed air powered venturi type are inadequate. The proper pressure when charged depends on the ambient air temperature. You need an R-12 table and thermometers. Be sure you connect the charging hose to the low side (suction side.) If you don't know what this means and how to do it, get some experienced help. A/C systems can blind, maim or kill you. Always wear eye protection.