Upper radiator hose collapsed

[Tubescreamer]

While checking my oil on my zx2, I noticed my upper radiator hose was collapsed. I took the radiator cap off and the hose popped back into place. What caused this? I don't have any overheating problems and my hose looks great. My anitfreeze is also full.
What should I do?

 

[Pablo]

Sounds like trapped air.

A weak hose.

Some cars have caps on the expansion tank that allow breathing in when system cools, then clamp shut when system is heated until release pressure could (possibly) open the release valve.

 

[W.T.McGlynn]

The upper hose is always the first to go.
Gates rubber says to change out every four years.
This way you don't end up at the side of the road.

 

[Chris142]

Your cap is bad.If you look closly the lower rubber seal has swelled out so that the coolant that was pushed out under pressure cant be sucked back in when it cools.

Or the jiggle valve is stuck.

Replace the cap.

 

[Shannow]

Chris, exactly what I was going to offer.

Hoses are designed to hold against pressure, not vacuum. when the coolant can't get sucked back in, the volume has to come from somehere, and top hoses get sucked in.

Having this situationm for too long can create weak lines along the hose, leading to early failure.

 

[Brent]

The cap is the most likely part to cause this problem.

If a new cap doesn't correct this, check the hose going to the recovery tank for obstruction.

Brent

 

[ikeepmychevytoo]

Hmmm... And I've always been wondering what the GM was thinking when putting a spiral metal wire inside the OEM upper hose.

 

[Tubescreamer]

OK my cap has some small caps in the rubber seal.
I bought a new cap.

Thanks