The only way to see if the AOS is OK is to check the crankcase vacuum. We have come up with a Manometer assembly that taps into the crankcase via the engine oil cap. This is the only way I know of to properly check the engine oil separator, without guess work. It takes me minutes to perform this procedure. I travel all over the USA and Canada teaching technicians my ideas on this, all promoted and sponsored through a company called Worldpac Training Institute. My next class is in Gaithersburg, MD next month.
WORLDPAC - Advanced Technical Training Program
Tony Callas