After changing 2 air tanks and putting on spring brakes I have found the last leak...(as if). It is in the pressure regulator. I saw Dallas's fix using a sheet of silicone but unfortunately the PO assembled this with one piece missing. I attached a snap of the reg and the missing bit is 4: spring seat. Tried fabbing one up but no luck yet. I'm thinking this is bone stock stuff but after having to re plumb for a rear tank that was not the same size I do not want to plumb in a replacement unless I have to. Maybe I'll pull apart a reg from a transit and see what I can find. Other option is someone drops one in the mail for me......All input as always appreciated.