<<<<Anyways, I know what that problem is
but while inspecting the slave cylinder I noticed a green fluid dripping from
beneath the engine. Oh No! I am really hoping this is not a head problem
since the heads were replaced 30k ago.>>>>

I have had several Vanagons.  Leaks come in all sizes and stem from a variety
of reasons.  My last two were from leaky hoses.  I have an '85 which only
leaks when it is very cold.  I have driven it numerous miles after refilling
and bleeding and it runs well, doesn't overheat, and doesn't leak until it
gets cold again.  Your leak may not be serious.

Tom
'71 Westy, '85 Westy, '91 Carat, '81 VW Diesel Pickup