96 C280 AC Evaporator Flush?

[Martineau Gauda]

Hi, I am replacing the AC condenser and reciever dryer because of small leak in condenser. Maybe refrigerant gone for 4 months.

Will evacuate system well before charging and add lost PAG oil. Is it recommended to flush the evaporator also to remove any old oil that may have accumulated moisture also?

Should I expect any major problems with remaining oil being contaminated with moisture because of 4 months without refrigerant.

Thanks