Update on this.  I think McNeely reported getting a replacement front
heater valve from NAPA, so I looked into that.  only $6, and they had
it at my local store the next day for pickup.  I did the "blow
through test" and no air went through it.  So I put it in place of
cpvc prototype mentioned below.  It will not flow as much coolant
when open as my cpvc version but at least I know it's compatible with
the coolant.  Seems to shut off fully, and it's getting to that time
of year when I want that.

Edward

At 09:54 AM 6/24/2011, Edward Maglott wrote:
>John,
>I have installed a prototype valve that shuts off all flow to both
>heaters in my 2.1.  It is installed in the heater hose near the
>driver's side driveshaft.  I made it out of CPVC because it was
>cheap.  I know that material is not compatible with the coolant, I
>will take it out promptly.  Probably will make the final version out
>of copper unless someone points me to a better choice at a similar
>price.  I used a 1/2' ball valve with about 3" of 1/2" pipe sticking
>out of each end.  Cut the hose and stuck the pipes into each end and
>secured with 2 hose clamps on each.  Works great.  You do have to
>get under the van to switch it on or off, but for the really hot
>part of the year that is probably fine.  It is pretty easy to reach
>and do without getting dirty if you lay down your piece of cardboard
>or tarp that lives between rear cushion and engine cover.
>
>Neither of my heaters turn off completely.  I don't notice it until
>it is really hot.  Even though there is no air moving past the rear
>heater it heats up the whole underseat cabinet and bed area if I
>drive  a few hours.  Not cool for sleeping.
>
>Edward
>
>At 07:46 AM 6/24/2011, John Rodgers wrote:
>>  I need to install a summer shutoff valve on the hose to the front
>>heater core. I just cannot get the heat valve to close tight enough, and
>>in this summer heat hot air blowing is a bit much. Is this procedure
>>posted on a website anywhere? Got a link?
>>
>>Thanks,
>>
>>John
>>
>>--
>>John Rodgers
>>Clayartist and Moldmaker
>>88'GL VW Bus Driver
>>Chelsea, AL
>>Http://www.moldhaus.com