Home › Forum › Ask A Member › Installing a telltale › Re: Installing a telltale
All true. Any liquid cooling system needs to be able to deal with air and other "non-condensible" gases, or at some point it is likely to get air locked and overheating will result. this means in practice that some means of venting from the highest point of the system is needed. Many cars do not comply with this because styling and aerodynamics results in radiators lower than the highest point of the cooling system. This often works when new but gives trouble as things age and leak. I’m learning that outboards have similar problems. There are various reasons why the water pump is likely to pump a certain amount of air and if this exceeds the ability of the system to get rid of that air bad things will happen. So I like the idea of a telltale at the highest point. Obviously this should not flow enough to defeat proper temperature regulation.
Chrysler has used pressure gauges, but I don’t think this is a complete solution as the gauge can’t distinguish between air pressure and water pressure.