I *just* finished bleeding the cooling system on my Vanagon when I DROPPED
the bleeder screw down into that netherland that comprises the front of my
van. I checked everywhere for it. I even let the van roll backwards (I have
a sloped driveway) and then slammed on the brakes, hoping to dislodge it
from its hiding place. No luck.  So, what size is that screw? It's the one
that fits in the bleeding hole on the passenger side of the radiator. Is it
even supposed to be a screw? I got the impression from the VW service
manual that it was a bleeder valve of some sort.
Thanks,
Joel