Crashed condenser coil

TJ_5

We have a 15 ton Trane/American Standard rooftop condenser set, with 2 7.5 ton (r-22) compressors, this runs into a flat plate heat exchanger, that is used as a chiller supplying chilled water to fan coils, univents and the like.  over the summer (system first year) the hx developed leaks between r-22 and chilled water, and the expected result, both compressors were blown.  The refrigerant looked like 90wt gear oil.  Both were changed, many filters installed in both suction and liquid lines as well as changed out all installed.  The lineset was flushed with r11 flush, then purged with n2, leak tested and vacum pump set up on the lineset.  We were able to get system down to 2000 microns, but the pump oil is coming out like skim milk blan white color.  changing oile every hour for the past 5 days.  Any ideas how to get lineset cleared up.  replacement of the lineset not a real option due to being concealed behind walls, ceilings etc.