Quote:
Originally Posted by cycleguy55
Radiator caps have 2 functions.
- hold pressure until the design pressure is reached
- allow return of coolant when the engine cools, the pressure drops and a vacuum is created.
Check the 1:15 minute mark of this video: https://www.youtube.com/watch?v=QhLUwsCdM08 |
Thank you for the aha moment. I did not realize there are two types of radiator caps, vented and non-vented. The vented type has a second valve to allow coolant to be pulled back into the radiator from an overflow tank.
I get it.