its only because the breather system is a stuid design by recirculating on itself

my rst i uses a bailey breather but hadit venting to atmosphere, this stopped two things

oil vapours being dragged back into the metering unit by turbo which took away the oil found in boost hoses and out of dumpvalve, and the stupid air leak problem when it cut out if you lose your oil cap as they do get worn and blow off

alls you do is thepipe that goes to the metering unit from seperator just leave that to atmosphere and block the hole up in the unit itself, so basically like a efi set breather