Brian,

I would use the Subie coolant conditioner stuff (sorry I don't know the
exact name or the link to purcahse it - but someone will chime in).

This stuff works by "swelling" your seals and gaskets. I've used it before
and it seemed to work great - I've heard lots of other people say good
things about it as well.

As for Bars Leak - I'm not for or against - I've never used it in a Vanagon.
You are going to get both sides of the story for sure.

Good luck.

--
Thanks,

Jeff
'90 Carat (Grover)
'86 (We call this one Parts)
'78 Bus (Melissa) Patty's Bus