i am reassembling my na 606 on a 95e300d after some doing some extensive head work and am having problems with the breather system used to recycle the blowby. all of the rubber and plastic tubes are cracked, broken, and brittle. i cannot tell if what looks like a pvc valve works or not. blowing through it or sucking through it in ether direction causes no change. what is this thing supposed to do and why is it on the car? if it is broke why do i need to replace it, can you bypass this thing and if not, why?

thanks, hunt