>Alistair,
>
>It's not pressurized?  It darned sure blew back in my face adn gave me 
>some nasty burns when I foolishly unscrewed the cap once.  I'm talking 
>about the cap on the coolant reservoir. 

It's the weight of the water in the rad, 2' higher up than the cap you 
undid, that pushes the water at you. This doesn't happen until the front 
'bleeder' screw is out. You need enough RPM to push back against that!, 
Higher RPMs push water/air out the rad 'bleeder'. Higher still and you can 
really drop the level at the cap, enough to add fresh antifreeze/H2O. Use 
your thumb on the throttle linkage to figure out the speed, I don't have a 
tach, but I'd say it was at least 2000 RPM, ie mid throttle not fast idle.  
About the hose from the bleeder up front, get some narrow plastic tubing 
1/4" or so, and screw it into the thread holes. Use a pencil sharpener/knife 
to taper it down a bit until the threads grab. Run this up and into the 
bottom of a big Coke bottle on the windshield, that you can see from the 
rear of the van, then pump/suck back until no bubbles come out.  This takes 
<5 minutes, judiciously revving the engine as needed. Have the fresh coolant 
handy, as you can't walk away to grab it without loosing a half gallon or 
so!  Good luck.     tim s.