Collapsed top radiator hose

[Corvette2]

2005 Silverado 2500HD 36K miles Diesel/Allison 4X4 X Crew: Noticed top radiator hose collapsed when engine cold. Level in overflow tank was a bit low (now topped off). Engine does not runs rough. Engine/heater operating temp. normal. When cold and open overflow res. cap, air rushes IN and hose opens a little. When hot and open res. overflow cap, air rushes IN and coolant flows out of overflow tube/cap. Hose expands to normal when engine at operating temp. ????

[unsolved]

As long as you have no leaks you have no worries. If the top hose collapses when it's cold the radiator cap isn't working properly or the overflow reservoir overflow hose is plugged.