[Excaliber]

A recent thread on an over heating issue pointed to:

The bead of silicon around the pump expanded out when the pump was bolted down tight, thus "squishing" out some residual amount around the inside edges. Months later little ridges of the residual silicon finally broke free and worked it's way into some water passages in the head gasket area. Thus causing just enough blockage to cause a very difficult to diagnose over heating problem!

I for one will use slilicon VERY sparingly from now on, just to "be sure".

Ernie