I wrote recently about a coolant leak that i noticed at the rear jack
point.  After removing the wood cover over the rear heater core, I can see
coolant below the rear heater fan.  I've tried running the engine while
looking in the area, and I can't actually see from where the coolant is
leaking.  I've done this with the valve opened and closed.

The leak doesn't appear immediately either.  Yesterday, I drove for a
while, parked for a couple of hours, saw no leak, drove home, let it sit
all night in the cold, and then I saw the leak this morning.  In addition,
this test was done with the valve closed the whole time, and the leak was
larger than that obsserved with the valve open.

Though I can't see coolant coming out from anywhere, does this sound like
the core has a leak?  Is it the case that leak might be happening when
things get cold and contract?  I guess I'm not sure what a leak in the
core usually means.

In any case, if it is the heater core leaking, I'm wondering if anyone can
provide a few details about changing the core.

So far, I understand that I can probably use some c-clamps to close of the
two hoses.  The core seems to be held in by a couple of screws at the
base, and it seems like I might have to unscrew the vent cover on the kick
panel in order to remove the core.  Are there any other places I'm not
aware of?

Once I have the core out, how do I reuse the valve on a new core?  Is
there any sort of gasket between the two, or is it just a matter of a
couple of screws?

Should bleeding be necessary if I've been able to prevent much coolant
loss during the operation?

I know these questions are rather simplistic, but I prefer to go into the
job knowing as much as possible ahead of time....especially since I'm now
living in a small mountain town where Vanagon assistance can be hard to
find.

Thanks for the help as always.

David