Working on a refrigerator 2 door continental with the condiment top, R-134 A. A fellow tech replaced a compressor, captube and drier and blew the lines out or so he says. A week later went back and replaced the drier he, found it restricted. I followed up to work on the box unit running warm low on gas, pressurize with nitrogen no leak found cut back on cap tube 1.5 inch, replace drier(CLEAN DIRTY CONDENSOR!!!) Did a triple evac after finding no leaks on my joints. Pulled around 300 microns on this system. A week later another tech went back and found a restricted drier. He called up continental and they told him to drill a hole in the receiver, isolate the evap and blow it out often oil gets trapped in there and its a good process to do after a burnout. He added a pigtail fitting to evap did as they told him and box is working fine now. Has anyone ever encountered this? The tech also stated when 134 gets extremely hot say from a really dirty condensor coil it often turns into oil due to high temp? if this is true why?