Should the upper-right radiator hose be collapsed at room temperature?

[Topless]

I noticed this today on my '79. I'm referring to the hose that runs from the thermostat to the coolant outlet. Is it normal for it to collapse when cooled?

[toyfiats]

No. It's not normal for any of the hoses to be collapsed at any time.

[18Fiatsandcounting]

As toyfiats mentioned, no, it's not normal. The cause is likely a bad radiator cap, or the wrong one. When working properly, this cap can release coolant into the overflow tank as the engine warms up, but then the cap should allow coolant to return back to the engine from the overflow tank when the engine cools down. That second part doesn't seem to be working, so the hoses collapse due to the vacuum upon cool-down.

The good news is that it means your coolant system is air tight.

-Bryan