it is just the accumulator and orifice tube sadly the accum tends to be very pricey. If the compressor to accumulator section hasn't been exposed for a day or two not leaky but exposed they need to be replaced. If your cleaning it a good idea is to replace the orfice tube. The system must be evacuated if left open for period of time.

If the compressor is ever drained make sure you add a few drops of oil directly into it so it does not start up dry it will burn up.

Even if your can meter shows proper zone it does not mean the system is at proper zone. The system cycles it needs to cycle thats what she does so you could be reading red and when the system kicks on it will jump into blue then is the tim to keep filling until you are at proper level.

 

now thats the info i was looking for, thanks to all who posted.