The coolant should be cool. These devices use density to infer the amount of coolant. Warm water is less dense than cool water (things expand when they get warm) Have you seen the temperature indicators that have floating balls in them, same thing.
http://www.monticelloshop.org/205167.html?product_id=205167+&adpos=1o1&creative=138037100315&device=c&matchtype=&network=g&gclid=EAIaIQobChMIgrLN0N6z1QIVy0oNCh3AdAxEEAQYASABEgIW1vD_BwE
1 Like