My a/c compressor burned up on me. So I will be replacing it. The manual says that any time the compressor is replaced, to replace the accumulator/ drier, and evaporator core orifice should be replaced as well. So far, so good. In reading about adding new refrigerant oil (YN12B) to the system, it has specific instructions on how much to add for each component based on how much old oil is drained from each component. I get the instructions for the compressor and accumulator/drier. Then it says that if you replace other components like the orifice or lines, to add 2 additional ozs. If I'm replacing orifice and flushing lines, do I add 2 or 4 ozs? Also, to flush the system, do those cheap flush systems from auto parts stores work we'll enough (they basically consist of a pressurized canister and small hose), or do I need to use a real a/c flusher? And if so, are there places that rent them? TIA

BTW- 96 F150, 3.9L straight 6 Eddie Bauer