During Component Replacement
When replacing the evaporator, add 3 ounces; for the condenser, add 1 ounce. If an accumulator is replaced, drain oil from accumulator through the pressure sensing switch fitting (Schrader valve removed). Measure the amount of oil removed, and add that amount plus 1 ounce to the new accumulator. No oil needs to be added to compensate for loss when valves or hoses are replaced.