I am working on a hill pheonix rack.One compressor on medium temp side keeps over filling with oil.this is the only compressor doing this.I have replaced the oil bowl,check valve on resivor,and replaced float in seperator.Compressor faults out every other day on oil failure at 2:30 in the morning.It is the only compressor that is overfilling with oil so I believe they have to be connected.I have noticed I can not matain oil level in resivor,oil keeps leaving resivor.If oil is going out into system why is it only overfilling the one compressor after a defrost cycle?System has 6 compressors 2 common suctions 1 on 2 low temp compressors and 1 on 4 medium temp compressors.1 common discharge header and 1 common oil return line.All pressures,tempatures,oil pressures,head tempatures,crankcase temps look good on compressors.I am lost on this though I am new to working on racks any help would be greatly appricated.It is a 2 hour drive to this store and I would love to resolve this issue.Thank's Tom