May have been leaking all along, a cylinder->cooling passage leak. Had that happen on my '85, would only act up in hotter weather and only under high power situations like climbing long highway grades. Cylinder pressure would force into the cooling system, over pressuring it and finally causing it to overflow the overflow bottle. Only happened while driving, so you could never see the leak. But once the coolant dropped enough, the engine would start to get hot.

r.c.brown@ieee.org
TruckEditor@tlca.org
Project: 4Crawler
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