Upper radiator hose looks like it is closing itself...WHY?

[econ]

Just did a bunch of work. Amongst other things, I replaced the upper and lower radiator hoses.

I bought the car new. The hoses that came off are the hoses that the car was born with. I never paid much attention to the original hoses. But now that I just replaced them, of course my eyes are all over the hoses that are on the car, looking for any issues.

So, engine off for about 24hrs. Everything cool, of course. Hose looks slightly collapsed. As though there is a vacuum on it. So I took off the radiator cap thinking that doing so would relieve any vacuum that is there and the hose would go back to its original resting position. Nope. No vacuum there at all. Hose stayed the same. So with the radiator cap off, I squeezed the hose in a way that would force it back to it's normal shape thinking that it might stay there. Nope. Went back to it's slightly collapsed resting state.

Then I thought that maybe it is this way because it is twisted. Maybe I need to loosen the hose clamp at the radiator, spin the hose a little and it will then fall back into a normal resting position. Nope. Nothing changed. It was not twisted.

The spring in the radiator cap seems to function smoothly as I depress it with a punch. The hose going to the overflow is unobstructed.

Before installing this new hose (GM OEM hose) it was normal. Not collapsed looking.

Maybe the old one was like this when it was on the car too. I don't know.

Any thoughts?

Here are some pics of various angles to give you an idea....

[econ]

I just noticed this today in the morning.

I didn't notice it when I had it running last night. Nor did I notice it when the engine was hot and turned off. Only cold and not running. Next time I have it running I will be paying special attention to this.

[econ]

And, full radiator.

Overflow tank shows coolant just below the full mark on the dipstick.

Just flushed and used dexcool.

Not sure what else to add...

[CamaroCracka]

Looks like vacuum created by the coolant volume going down as it cooled and the hose retained that shape. Try warming it up with the cap off and letting it cool that way to see what happens. If it keeps its normal shape, your call on whether or not to replace the hose with a higher end piece.

[1JEWLDSSRS]

When my Camaro did that, I just replaced my hoses with the Mishimoto silicone ones, and no issues since then. They just get old and collapse after all the years and the pressure/vacuum. These, of course mine were for the 2011..

https://www.mishimoto.com/chevy-cama...2012-2015.html

[econ]

Originally Posted by CamaroCracka

Looks like vacuum created by the coolant volume going down as it cooled and the hose retained that shape. Try warming it up with the cap off and letting it cool that way to see what happens. If it keeps its normal shape, your call on whether or not to replace the hose with a higher end piece.

Warming it up with the cap off? As in warm the hose up with a heat gun or do you mean run the engine?

But as vacuum builds in the cooling system, that vacuum should get relieved through the radiator cap allowing the system to pull from the overflow tank. The fact that vacuum built up enough to do this means that the cap is bad? Or is this normal even with a good cap? The cap has a 20psi rating, so it takes a decent amount of pressure or vacuum to get it to relieve...

[econ]

Originally Posted by 1JEWLDSSRS

When my Camaro did that, I just replaced my hoses with the Mishimoto silicone ones, and no issues since then. They just get old and collapse after all the years and the pressure/vacuum. These, of course mine were for the 2011..

https://www.mishimoto.com/chevy-cama...2012-2015.html

These hoses are 1 day old...

Just installed them.

Thanks for the link for the silicone hoses. Might consider that down the road.

[Mouse330]

Try this first -
Put a new cap on it. A faulty cap can create a vacuum causing the hoses to collapse. Its not regulating the coolant system pressure properly.

[1JEWLDSSRS]

Originally Posted by Mouse330

Try this first -
Put a new cap on it. A faulty cap can create a vacuum causing the hoses to collapse. Its not regulating the coolant system pressure properly.

Yes, and agreed, this could be an issue as well. Good luck.

[CamaroCracka]

Originally Posted by econ

Warming it up with the cap off? As in warm the hose up with a heat gun or do you mean run the engine?

But as vacuum builds in the cooling system, that vacuum should get relieved through the radiator cap allowing the system to pull from the overflow tank. The fact that vacuum built up enough to do this means that the cap is bad? Or is this normal even with a good cap? The cap has a 20psi rating, so it takes a decent amount of pressure or vacuum to get it to relieve...

You said you removed the cap and the hose stayed the same shape, so I was thinking if you warm the coolant by running the engine, perhaps it will return to it's original shape. Having the cap off eliminates the possibility it immediately collapses as it cools. I'm really thinking the hose is not the strongest, but it could be the cap is stuck.

[1JEWLDSSRS]

Originally Posted by CamaroCracka

You said you removed the cap and the hose stayed the same shape, so I was thinking if you warm the coolant by running the engine, perhaps it will return to it's original shape. Having the cap off eliminates the possibility it immediately collapses as it cools. I'm really thinking the hose is not the strongest, but it could be the cap is stuck.

Yep, I've seen this happen back in the day when the hoses were of sub par quality and not thick/strong to handle the pressure.

[econ]

UPDATE:

Replaced radiator cap and replaced new, oem radiator hoses with Mishimoto hoses.

Problem taken care of.

[1JEWLDSSRS]

Originally Posted by econ

UPDATE:

Replaced radiator cap and replaced new, oem radiator hoses with Mishimoto hoses.

Problem taken care of.

Awesome brother!! Glad you got it squared away. Thanks for the update!!