I think maybe you aren't getting the air out of the radiator, and that's
why you're getting so much steam from the bleeder on the engine.  (The
radiator is air-locked, so it's overheating and boiling the coolant.)  The
radiator bleeder is on the upper left corner, behind the upper grille, if
your van is like my '82 diesel.  I'm told it's easy to strip/break so
don't crank down on it too hard.  Also, make sure you open the heater
valves at some point so you can flush any air out of the heater core.

This may also be why your fan is erratic.  The thermo switches are
probably sitting in an air pocket. ;)

AFAIK there'll be no flow at the radiator until the thermostat opens, so
don't expect any action until the engine warms up.  Once it does you'll
probably get a lot of air hissing out of the bleeder when you crack it
open, followed by a trickle of coolant.  Make sure you close the bleeder
again before shutting off the engine, since once the water pump stops it
may try to suck air back in (and overflow out the expansion tank, if the
cap's off.)

I'm a novice at this too, though, so don't take my words as gospel.  And
my all means let me know how it goes, I need to drain/flush/fill my
cooling system soon.  I had a blown head gasket I just fixed and now
there's a lot of oily, sooty crud in the coolant I want to get out.

             _ _
  __ _ _   _| | |  | David M. Brodbeck (N8SRE)              Ypsilanti, MI
 / _` | | | | | |  +-----------------------------------------------------
| (_| | |_| | | | @ cyberspace.org
 \__, |\__,_|_|_| "Geekdom is fantastic at being AGAINST something, and
 |___/             it's hopeless at being FOR something."
                                      -- Andrew Orlowski in The Register.