Hey Guys, I was replacing the radio pod on my GTA, and I broke that little valve that has all the vacuum lines on on it that control (Max, Norm, Bi-level, Heat & defrost) for the AC. It was hissing when I shut the ac off. So I bought a brand new one from the dealer, it was $15. It is just a little round plastic piece with a rubber diaphram in it and the vacuum lines go to it. Well I put it in and it was fine for about a week. Now when I put the heat on it hisses for a while before stopping. Then once it stops it is fine. But if the car sits a while it hisses again for a bit and then is fine again. I checked it out and all the vac lines going to the part are fine and connected. Is it possible this part that I bought is defective?? I don't know what else it would be since I hear the hissing coming right from there. Any help would be appreciated. My controls are just the slide type, they are not digital.
Thanks!!
Mike

 

The hissing is normal, that's the sound of vacuum moving through it to get to the little diaphragms.

You don't want a vacuum leak under your dash, that stuff is nasty. You have to use a special tool called a "vacuum cleaner" to get all the little piles of it up. And it's hazardous waste too, it has been conclusively proven that laboratory rats can only survive for a few seconds in an atmosphere of pure vacuum. At least it cures cancer though.

 

LOL RB83 about that "Special tool". I know the hissing is normal for a few seconds, but not for a few minutes. When I step on the gas the hiss quiets down. It then eventually goes away. But if I shut the car off and come back to it about an hour or two later, it is hissing again. I never had any problems until I replaced the radio pod. Then I broke the valve piece. And when I bought the new Valve it was ok for about a week. Now it is hissing, and it is definitely coming from that valve. Could it be that Diaphram in the valve piece?? That is the only piece I can see being the problem.
Later
Mike