Does anyone know what size the bolt is for the oil breather chamber and the size of the o ring? I went I all the parts stores and they have no clue what I'm talking about. I told them it might be under oil separator and they said they don't carry the parts.

 

dealer or junkyard.

 

Look at parts diagrams at hondaautomotiveparts.com

I haven't looked, because you haven't told us what you drive, and what engine you have. I would guess they are M6 or M8 bolts, 10 or 15mm long.

The o-ring should be removed and matched up at a parts store using an o-ring kit. AutoZone usually has a large o-ring kit in the back for shop customers. Match it up that way, or if the o-ring is listed on that website I listed above (should be), use those dimensions provided.