In article > ,
Adrian > wrote:

>Clue :- There's very few cars from the last couple of decades that have a
>cap on the rad itself. Virtually all have the cap on the header tank.

Eh? My 1999 certainly has the cap on the radiator; you can see the
core through the neck when it doesn't have enough fluid in it. So
does my 1997. The overflow tank just has a simple plastic cap, not a
pressure cap.