L76 Top Radiator Hose

[bigjim92]

So, last week dad was washing the SSV, and he noticed that the upper radiator hose had flattened itself, as you can see in the picture bellow.

If the car is running everything is fine, but once the car has been turned off the hose will flatten/collapse.

It was at Holden yesterday, and they say they see it all the time and it's perfectly fine. I find that very hard to believe! They also claimed another issue to be normal as well, until we showed them otherwise.
They say it's just air pockets, and they claim to have bled the system. But again today, the hose has flattened/collapsed.
Surely this is not a normal thing to see...?

 

[RiCeY]

When the coolant cools it contracts and creates a vacuum. A properly operating coolant cap will equalise the pressure and draw in coolant from the overflow.

If this isnt happening I would replace the coolant cap.

 

[Muke]

Another possible stupid question by me. Don't the radiator hoses have springs in the ends to stop them collapsing (or flattening)? I'd have thought that'd only be there if flattening happens sometimes and it's just to make sure the end doesn't collapse and possibly open a gap on the connection? Or worse come off. Haven't done this car, but the VN had those springs from memory (which admittedly isn't great). Or is that an extra safety margin so you don't dump all the coolant at once if the hose or cap is on the way out (resulting in the flattening)?

But yes, as Ricey says it also makes sense to check the coolant cap as not all cars do that (i've never seen/noticed it) and that reason makes sense to me. And it doesn't hurt to check. (Not to mention Ricey usually appears to know what he's talking about).

 

[Boonz]

I think you will find thats how the top hoses are formed. Have seen quite a few L76-L77 motors with hoses this shape because even when you release the pressure it stays the same

 

[RiCeY]

The hoses dont have springs in them no.

 

[bigjim92]

I think you will find thats how the top hoses are formed. Have seen quite a few L76-L77 motors with hoses this shape because even when you release the pressure it stays the same

If you release the radiator cap the hose becomes round, which is what it should be.

Ricey, you're the second mechanic outside the Holden dealership I went to that said probably the radiator cap.
The car was back at Holden today, two other mechanics looked at it and agreed it was not right, so they've changed the radiator cap, and so far all seems ok, lets hope it stays that way.