The TK valve is a way to stop the heat without doing a proper repair.
The proper repair is to replace the stock valve with a new one and make
sure the cable is straight and adjusted right. Some people find this
challenging and so the TK valve is a quick and dirty way to avoid the
real fix. I prefer the real fix and have done it to more Vanagons than I
can remember.

Quick and dirty fixes have their place. The TK valve works fine for the
guy who puts it in, knows it is there, and remembers to use it. The
problem I have with it and other Q&D fixes is that they accumulate until
there are so many added quirks and annoyances that the SO never wants to
take the van anywhere.

Mark

Tom Buese wrote:
> So am I correct in understanding that the TK valve is to rectify a
> seal problem in the vent. box & if you don't have this problem, you
> don't need one?
>
> Tom B.-Carl, The Gr. Pyr. appreciates cold air or none at all down
> there.
>
>