Consider surface areas exposed to the coolant. Open pipe area is a whole
different influence than the brass that may be on the outside of a temp
sensor. Amps run on the surface of the metal, and are carried in the
coolant on metal molecules eaten off the exposed metals. To prevent this
process from eating up your Wasserboxer, don't add copper based pipes, use
coolant as specified, and completely change the coolant BEFORE it goes
acidic. Yearly guarantees it never will go acid, no corrosion EVER getting
started. Every 2 years is an experiment that might work if you start with a
totally corrosion free SYSTEM. Three year intervals with half volume
change, which was/is the norm at VW dealers will guarantee leaks in the 3rd
iteration or so, several years out of warranty.

At 07:52 AM 09/16/2003, you wrote:
And the brass inserts in the ends of the long plastic coolant pipes,
>and the H2O temperature sensor....
>
>Steve
>'86 Westy "Escape Pod"
>