Hi guys have Trane close control unit in a server room with 2 circuits. Circuit 2 has poor of coil temp and low suction pressure, traced to the filter drier beginning to block up as temperature is lower on outlet side. Also both circuits sight glasses are just beginning to show wet. Plan is to reclaim both circuits, too also confirm issue is not low refrigerant charge then cut out driers and braze new ones in. Question is should the refrigerant also be replaced or reuse existing and see if sight glass shows dry. Refrigerant is r407c and given the high cost trying to save the client some money.