coolant circuit early 123:20-005 PDF

A technical documentation that outlines the coolant circuit and engine cooling system for early models 115.1 and 123.1 up to February 1979. It includes technical diagrams illustrating the coolant circuit structure and the role of various components like the water pump and thermostat. The document discusses the operation of the thermostat across different engine temperatures and provides visual instructions for vehicle layout with and without air conditioning. It also addresses the specifications for antifreeze use, venting methods, and explains engine cooling under various conditions.