Climate Control Vacuum
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Joined: Sep 2010
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From: Nashville TN
Climate Control Vacuum
After the ls3 swap into my c5 z06 I noticed around the same time my a/c wasn't blowing out of the vents I wanted it to.
The display works, heater and a/c both change when I adjust the temperature **** but the air seems to just blow out of all the vents.
I never use the a/c anyways so I wasn't too concerned of it but now its winter and I'd like the heat blowing correctly.
I found this while searching and noticed that the "main" vacuum line that supplies the hvac block under the passenger foot well does not seem to be getting any vacuum.
http://forums.corvetteforum.com/c5-t...nge-vents.html
I checked the back of the intake and it only has one line running out of it which goes to the brake booster.
I found the vacuum supply 90 degree rubber elbow that connects to a hard plastic line sitting right behind the intake that is not attached to anything. Its just hanging there and runs into my wiring harness. I believe this is the reason why my vents do not adjust when I change the settings in my car.
So my question now is where would be the best location to tap into the intake to get a new source for my hvac system?
The display works, heater and a/c both change when I adjust the temperature **** but the air seems to just blow out of all the vents.
I never use the a/c anyways so I wasn't too concerned of it but now its winter and I'd like the heat blowing correctly.
I found this while searching and noticed that the "main" vacuum line that supplies the hvac block under the passenger foot well does not seem to be getting any vacuum.
http://forums.corvetteforum.com/c5-t...nge-vents.html
I checked the back of the intake and it only has one line running out of it which goes to the brake booster.
I found the vacuum supply 90 degree rubber elbow that connects to a hard plastic line sitting right behind the intake that is not attached to anything. Its just hanging there and runs into my wiring harness. I believe this is the reason why my vents do not adjust when I change the settings in my car.
So my question now is where would be the best location to tap into the intake to get a new source for my hvac system?
Le Mans Master
Joined: Oct 1999
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Doing a little digging around, does the back of the LS3 intake look like this?
check this post out
http://forums.corvetteforum.com/c6-t...questions.html
check this post out
http://forums.corvetteforum.com/c6-t...questions.html
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Joined: Sep 2010
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From: Nashville TN
Thanks for posting that. I was able to look at it today and it looks exactly like that picture. Can that small port be used as my vacuum source? If so how do you properly remove the cover of it to access it? Does that cover that sits on top of it remove the plug?
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From: Central PA. - - My AR15 identifies as a muzzleloader
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It looks like a breakaway tab, but I don't know for sure. Mine never had that. But, yes, that's the source for the hvac vacuum. Be sure that the emissions tubing down under the battery is good too. That stuff gets brittle and breaks down there. Then, you may end up opening the access panel for the right front fender to get in to the fittings and vacuum brake for the hvac and holding tank. If one line isn't there, chances are, the rest are in need of repair also. The vacuum brake is available at the auto parts store for $3 (Dorman part), and the only other thing you need is the tubing. Good luck.
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I agree with K-Spaz. Breakaway tab. 
Don't worry, you're not going to remove that "plug" by breaking off the small breakaway tab. That big plug is in there TIGHT, and yes that is the source for your HVAC vacuum. You can use any source you want for vacuum, that's just the one the factory uses. I had to do the same thing on an LS7 manifold.
The other, bigger, plastic piece (straight) that sticks out going rearward is to protect the small vacuum hose from being knocked off, or moved, when installing the manifold or from the wiring harnesses, pcv hose, etc that runs around behind the manifold.
Don't worry, you're not going to remove that "plug" by breaking off the small breakaway tab. That big plug is in there TIGHT, and yes that is the source for your HVAC vacuum. You can use any source you want for vacuum, that's just the one the factory uses. I had to do the same thing on an LS7 manifold.The other, bigger, plastic piece (straight) that sticks out going rearward is to protect the small vacuum hose from being knocked off, or moved, when installing the manifold or from the wiring harnesses, pcv hose, etc that runs around behind the manifold.
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Joined: Sep 2010
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From: Nashville TN
So that "upside down wing nut" looking thing attached to the small nipple just brakes off and allows you to put a hose on it for the vacuum source? It doesnt look like it's plugging the hole currently.
I've had this sitting on my car for months without anything attached to it.
I've had this sitting on my car for months without anything attached to it.
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From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
Well, it certainly looks like a breakaway tab, and mine doesn't have it. Nor have I ever seen pics of an intake with it before. It may just push up or down out of the way for all I know.
But yes you are correct, even with it not plugging the vacuum line, you won't notice it. Lots of people have air door issues due to the vacuum lines being brittle and broken, without seeing it on a gauge or in the way the car runs. It's not a big enough leak to matter.
Lonestar.... Yer kidding right? Look man, now I have to clean my vomit out of my keyboard, thanks! Please update the avatar at your earliest convenience...
But yes you are correct, even with it not plugging the vacuum line, you won't notice it. Lots of people have air door issues due to the vacuum lines being brittle and broken, without seeing it on a gauge or in the way the car runs. It's not a big enough leak to matter.
Lonestar.... Yer kidding right? Look man, now I have to clean my vomit out of my keyboard, thanks! Please update the avatar at your earliest convenience...
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