Very interresting, i didn't know one actually got something like this. Appart from the rubber o-ring that seals it, how is it held in the block? I can imagine the water getting hot and build up enough steam pressure to push it out. That on bolt atop the two connection terminals looks as if it has something to do with the holding it in. Elaborate please.

We had a Our Mazda 1000 that had an A14 would sometimes freeze up in winter. This was in a North Western town called Klerksdorp. In winter it regularly goes below freezing far enough to allow the water in the block to freeze. Strangely enough the other cars that we owned didn't freeze up for some odd reason. Maybe because they used anit-freeze... First time it happened, my dad started the bakkie, en it made a terrible screeching noise, as the belt was spining over the stationary waterpump. He "fixed" the problem by unfreexing the pump with some boiling water from a kettle poured over the water pump. When it turned freely, he started the engine and drove off. Heaven knows how that A14 ever lasted as long as it did...