my car is overheating and when it does there's so much negative pressure on the upper radiatior hose that it is sucked in and collapses and turns flat...when i take the radiator cap off there is a vaccum on it and when removed all the air rushes down the hose...is this because the thermostat isn't opening or any other reason...? the hose for the ast for the air to come out is also dangling and i was wondering if there was anyplace it goes..thanks for your help...

 

I am having the same problem... I'm thinking it's the AST cap... anyone else encounter this or have any knowledge on why it would collapse so drastically after cool down?

 

this doesnt happen to my car- thank god! (no offense to you guys)

 

the hose off the ast needs to be plugged into the filler neck(the same thing that your radiator hose is plugged to). after that fill it up with coolant or water, it may take a few days to get all the air out. keep burping it.

 

just get an ast eliminator form m2 performance and your problem will be gone.

 

I remember in the old days that some radiator hoses has a stainless metal spring in them for the purpose of not collapsing. If burping etc... does not work, you could go to your local parts house and buy a hose with the spring in it and use that.