Top Radiator hose shrinks

[El Ed]

I have a 95 DI and I noticed that when the engine is turned off and it is cooling down, the top radiator hose eventually shrinks or collapsed as though there is a suction or vacuum inside. In other words, after the engine has cooled, the sides of the hose are stuck together. Anyone have this problem or know what it may be?

I should mention that when the engine is on, it reverts back to it's normal diameter and works fine I am assuming.

Thanks in advance,
Eddie

 

[javelinadave]

No doubt that you have a very tightly sealed cooling system. If you are not adding coolant I would say that things are fine. If the upper hose is more than a few years old you may want to change it out, all that shrinking and expanding has to be wearing something out.

 

[Trey & Melissa Burns]

Test the coolant cap-it is probably bad.

 

[SR20gawd]

Test the coolant cap-it is probably bad.

yup, that is not normal. As your engine warms up, and heats the water above 212? degrees it wants to boil and expand. However, your radiator cap keeps the system pressurized, and in turn raising the boiling point. Rad Caps are rated in PSI and Kpa, usually 9 - 10 PSI is a normal rating for a cap. Once 10 PSI is exceeded, the cap opens and bleeds off expanding coolant into your overflow tank. Once you shut off your engine and your coolant cools down, a vacuum is created in your cooling system from the coolant contracting as it cools. The rad cap opens again, to allow fluid from your overflow to fill your cooling system again. If the cap is not opening, then the vacuum will suck in the top rad hose in (as it usually filled with mostly air). By having a rad cap that isn't opening, your coolant system is not able to breath as it should, you definitely need to replace your cap.

-Howard