Hi all,

After a run, and then sitting at tickover, what would cause both the top and bottom Rad hoses to be sucked flat?

regards

Tom

The system is drawing a vacuum on itself as it cools down. The radiator cap is supposed to allow overflow bottle water to be drawn in to relieve the vacuum and is not. The small metal center of the cap bottom in the middle of the rubber washer is probably stuck to the rubber washer.

 

Yeah, i think someone else on the board had the same problem and it was fixed with a new radiator cap. Let the car cool down for a few hours, then remove the radiator cap and have a look. They're pretty inexpensive, so you might want to try replacing the cap first and see if that solves the prob. Let us know.

 

- Ed

I'd also replace both top and bottom hoses. They should hold upto that vacume and not pinch shut. If they fell all squishy then its time to replace them. You'll notice how rigid new ones are when you get them. New clamps is also good I always use a 1/4" drive rachet and socket on them now to get them good and tight.

MorganM:

 

So squishy feeling radiator hoses = replacement time? That's good to know.

 

My car is 6 1/2 yrs old and has 105,000+ mi and I've been keeping an eye on the radiator hoses wondering when I should replace them. They don't look bad, but I felt the lower one while under the car the other day and it did feel "squishy." Not knowing any better, I thought that was normal.

Might as well do the thermostat when you do the hoses.

 

Another tell-tale sign of a bad hose is the end near the clamp starts to bulge a little.