Manifold Vacuum Fitting
Thread Starter
Racer
Joined: Apr 2008
Posts: 406
Likes: 46
From: Lebanon OH
Manifold Vacuum Fitting
Can anyone identify the proper manifold vacuum fitting for a 1982? The one currently on the car has two ports on the same side, one over the other similar to the ones listed for 73 - 75 by vendors. The lower port is broken and plugged with a screw. I've also seen this same fitting on other 82 manifolds. However, the vendors show a three port fitting with one on top and two on opposite sides to each other. I suppose technically it doesn't matter except if I only need two ports, I have to plug the third. I'd also like the car to be as original as possible. Thanks.
MajD
MajD
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Below is a picture with the original part numbers of the vacuum fittings for 1982 only. The part numbers might help you locate an original one, both are discontinued.
Willcox
https://willcoxcorvette.com/
http://repairs.willcoxcorvette.com/
Willcox
https://willcoxcorvette.com/
http://repairs.willcoxcorvette.com/
Thread Starter
Racer
Joined: Apr 2008
Posts: 406
Likes: 46
From: Lebanon OH
So please help me understand why the replacement ones have three ports and the stock has one or two. I found a picture of an old crossfire intake on E-bay and it had a two port fitting. Can I use any two port fitting from a different year / car as long as the threads into the manifold are correct? Thanks.
8th Gear
Joined: Aug 2019
Posts: 8
Likes: 3
From: Sicklerville, New Jersey
MajD,
Curious if you ever identified the information you were looking for? Ive been replacing the vacuum lines in my 80' and noticed i have a three port fitting coming off the intake manifold, with one port not connected to anything. One port goes directly to the headlight system, the other to the break booster, and the third directly to atmosphere. Should something be connected to this? If i have nothing required to be connected, should i replace with a two port fitting?
Thanks!
Curious if you ever identified the information you were looking for? Ive been replacing the vacuum lines in my 80' and noticed i have a three port fitting coming off the intake manifold, with one port not connected to anything. One port goes directly to the headlight system, the other to the break booster, and the third directly to atmosphere. Should something be connected to this? If i have nothing required to be connected, should i replace with a two port fitting?
Thanks!
Instructor
Joined: Jul 2012
Posts: 171
Likes: 22
From: Kentucky
MajD,
Curious if you ever identified the information you were looking for? Ive been replacing the vacuum lines in my 80' and noticed i have a three port fitting coming off the intake manifold, with one port not connected to anything. One port goes directly to the headlight system, the other to the break booster, and the third directly to atmosphere. Should something be connected to this? If i have nothing required to be connected, should i replace with a two port fitting?
Thanks!
Curious if you ever identified the information you were looking for? Ive been replacing the vacuum lines in my 80' and noticed i have a three port fitting coming off the intake manifold, with one port not connected to anything. One port goes directly to the headlight system, the other to the break booster, and the third directly to atmosphere. Should something be connected to this? If i have nothing required to be connected, should i replace with a two port fitting?
Thanks!
Thread Starter
Racer
Joined: Apr 2008
Posts: 406
Likes: 46
From: Lebanon OH
emitchell57 and nearflack,
From what I can tell, you can no longer get an original 82 vacuum attachment. I have not heard whether or not a 73 - 75 one will work, but I'm tempted to try it. Ultimately, any port that fits in the manifold will work, as long as there are enough "tees" and other hose adapters to provide vacuum to all the systems. I'm just trying for originality. If you're not concerned about that, I would go ahead and buy a vendor vacuum port and just plug the third port. I may end up doing this myself until I can find an original.
Nearflack, if i understand what you are telling me, you need to go to the auto parts store and get a vacuum cap from the help section and put over the open vacuum port. The open port is bleeding vacuum and causing the headlights (and other systems) to not properly function. If that doesn't fix the problem, send me a PM and we'll look further into the issue. I've rebuilt my light system and can probably help you fix yours. I hope this helps.
MajD
From what I can tell, you can no longer get an original 82 vacuum attachment. I have not heard whether or not a 73 - 75 one will work, but I'm tempted to try it. Ultimately, any port that fits in the manifold will work, as long as there are enough "tees" and other hose adapters to provide vacuum to all the systems. I'm just trying for originality. If you're not concerned about that, I would go ahead and buy a vendor vacuum port and just plug the third port. I may end up doing this myself until I can find an original.
Nearflack, if i understand what you are telling me, you need to go to the auto parts store and get a vacuum cap from the help section and put over the open vacuum port. The open port is bleeding vacuum and causing the headlights (and other systems) to not properly function. If that doesn't fix the problem, send me a PM and we'll look further into the issue. I've rebuilt my light system and can probably help you fix yours. I hope this helps.
MajD
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Advanced
Joined: Feb 2013
Posts: 57
Likes: 5
From: Kingston, Ontario
I ordered the double vacuum fitting from the 74-75 engine and it was a perfect fit in both manifold threads and vacuum port size. My car is an 82 that I added cruise control to.
Last edited by j61man; Mar 20, 2020 at 12:02 AM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
If you have an "open" port on your vacuum fitting, you have a major vacuum leak and the other connected lines are not getting adequate level of vacuum. As a MINIMUM, you need to cap that unused port.
Instructor
Joined: Jul 2012
Posts: 171
Likes: 22
From: Kentucky
thanks I agree. The headlights work but are slow which I suspect is caused by this decrease in vacuum. I think with the help of the forum I have figured out that this open port should be connected to the transmission modulator. Will do that tomorrow hopefully that will solve two issues. Thanks for your response
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
So please help me understand why the replacement ones have three ports and the stock has one or two. I found a picture of an old crossfire intake on E-bay and it had a two port fitting. Can I use any two port fitting from a different year / car as long as the threads into the manifold are correct? Thanks.