New, R12 Rotary compressors come with a full system charge of Mineral Oil, which is compatible only with R12 refrigerant. New 134a rotary compressors come with a full system charge of PAG oil, which is compatible only with 134a refrigerant.
Furthermore, does 134a have oil in it? Yes there is oil in the system to keep the compressor lubricated. It is carried throughout the system in the refrigerant. It is usually added in when the system is charged.
Considering this, can you add too much oil to AC compressor?
While installing a new compressor or any other parts in your AC system, it is imperative that you add the correct amount of oil. If you add too much oil to the system, it may pool in various places of the system and can coat the inner walls of the evaporator and condenser coils.
Does vacuuming AC remove oil?
Just getting around to trying to get the AC to work. Pulling a vacuum will not remove the oil. Most of the time unless you replace your compressor or accumulator you should not need to add oil.