[Nutbutt]

Now I understand, I have seen that clean side breather. I was told that it needed a check valve as this is only to add air with another oil separator in line.
A setup without another can could have caused it. Really surprised the mightymouse guys wouldn't have told you. I have found the GM breather on the clean side with stainless material added to the inside adds good protection to the clean side.
Let me know how the new can works out. I have gone through 3 different ones and still not satisfied.