I have had the joints at the rear of the two main white coolant pipes
fail more than once.  I've also had one of the joints at the front of
the van fail.  The cause of the failures are cracks around the metal
insert in the end of each pipe.  It looks like the fittings back out
from vibration and begin to leak.  Replacing the pipes should fix the
problem.

I am going to replace the pipes when I get the extra cash, my local VW
shop has them for $110-120 each including shipping plus tax.  The
shipping is pretty expensive because UPS won't ship them.

dave
87 Vanagon
88 Fox