Well imagime my suprise. I was hooking up the battery tender on the 50th anniv. when I looked down at the upper radiator hose. It was flat as a pancake. I opened the tank cap and it sucked air into the vacuum. My question is this, is this normal for a vacuum to form when the weather gets cold and the car is in storage (50 degrees avg.). and or do I just need a new radiator hose? anyone have a suggestion??  

If you haven't driven the car in a while, then you prolly need a new rad. cap.
It is normal for there to be a vacuum in the system after driving. Once the coolant cools down, it will create a slight vacuum, and that is what will pull the coolant back into the rad. from the overflow tank. Sometimes it will completely collapse the upper hose, but usually only for a minute or so.
But...if the car hasn't been driven in the last couple of hours, there is either a restriction in the hose from the rad to the overflow tank, or the cap is bad.
You didn't say if you had been driving or not...

Thanks Joel, the car has been in winter storage since late October. Is there a way to check the rad.cap for pressure?

Mike,

OK Dave.  but what about originality? I haven't had to replace anything yet.

Joel would it not be prudent to see if this occurs after flooring it from a dead stop? jt's732008-01-11 19:14:58

[QUOTE=great pumpkin] Thanks Joel, the car has been in winter storage since late October. Is there a way to check the rad.cap for pressure?

[/QUOTE]

Soitanly!
Terry, there is a pressure tester for checking the rad caps, but I don't think it is capable of checking the suction aspect of the cap. If you are concerned about keeping the car original for later, go ahead and get a new cap, so you can at least drive the thing without having to worry about it. Then, when the time comes, say, you have it judged, or show it, just pop the original cap back on. Us NCRS guys do stuff like this all the time!
Some of the older, original caps just won't hold the pressure, and the car will puke...not a good thing when doing a PV(Performance Verification) test, or even the Operations check. So...on goes the newer, good cap for that, then swap for the original for judging.

Then again...your cap may have been defective to start with, and you just happened to notice it now. After sitting that long, there shouldn't have been any vacuum on the system anyway, so at least ya know there ain't no coolant leaks!


btw, John...that is NOT a cure-all for everything that ails yer car! ...it IS fun, tho, ain't it?

OK.  Looks like I'm going to replace the Hose and the cap cause I just gotta drive the thing!