I have had the funkiest intermittent leak of something that looks like "PB Blaster" that I thought was coming from the tank vent/overflow. Turns out it is coming from the crankcase vent return line. It is tight. And re-tight. (edit/July 2019: my leak is from the vent/overflow, but read on, as there is good info on the return line and changes to those fittings over the V11 production run . . .)   Is there any hope when these start to weep?