CRG Discussion Forum

Camaro Research Group Discussion => Maintenance => Topic started by: CantRepeat on April 03, 2021, 02:36:54 PM

Title: AC plenum valve
Post by: CantRepeat on April 03, 2021, 02:36:54 PM

As I'm working through the AC vacuum system on my 67 I have discovered that the plenum valve and flap assembly is missing.

I've got a restored piece ready to install but before I do could some one tell me what purpose this assembly served? Is to let fresh air into the system/cabin?

Is it possible to remove the cowl vent grill without removing the windshield trim? Obviously it will need to come off to install the new plenum valve assm.

Thanks!

Title: Re: AC plenum valve
Post by: Petes L48 on April 03, 2021, 10:10:19 PM

If you search the Heating & Cooling section at the TC site with key words , there are numerous discussions.  As this one mentions, check out the 67 Chassis Service Manual for an overview of how the system works.

https://www.camaros.net/threads/ac-vacuum-controlled-dampers.280601/#post-2425665

I think the grill should come out, but first lay down masking tape so no paint gets scratched.

Title: Re: AC plenum valve
Post by: CantRepeat on April 04, 2021, 10:24:15 AM

Thanks.

Like most forum search engines, I wasn't getting many fruitful results.

Title: Re: AC plenum valve
Post by: decarter67 on July 15, 2021, 01:39:11 AM

Tim -

Any chance you still have the cowl grill off your car?  When I had the bodywork done on my car with the intent of adding factory air, I had a new firewall welded in, but didn't know about the cowl plenum valve and the cut-out needed to install it.

Any chance you - or anyone else reading this - has some accurate measurements for that cut-out on the top of the cowl?  I'm going to have to make that cut myself and would like to get it in the right spot and the right size!  I've seen one set of photos that give a pretty good picture of where it's located, but if possible, would like some real measurements.

Thanks in advance for any info.

Dale

Title: Re: AC plenum valve
Post by: Petes L48 on July 15, 2021, 04:07:03 AM

Too late to take measurements, but here's a few more pictures for you.  67 11B LOS.

Title: Re: AC plenum valve
Post by: CantRepeat on July 15, 2021, 09:59:37 AM

Quote from: decarter67 on July 15, 2021, 01:39:11 AM

Tim -

Any chance you still have the cowl grill off your car?  When I had the bodywork done on my car with the intent of adding factory air, I had a new firewall welded in, but didn't know about the cowl plenum valve and the cut-out needed to install it.

Any chance you - or anyone else reading this - has some accurate measurements for that cut-out on the top of the cowl?  I'm going to have to make that cut myself and would like to get it in the right spot and the right size!  I've seen one set of photos that give a pretty good picture of where it's located, but if possible, would like some real measurements.

Thanks in advance for any info.

Dale

Sorry, I don't. I put it all back together shortly after this post.

Title: Re: AC plenum valve
Post by: decarter67 on July 15, 2021, 07:37:43 PM

Thx for the photos.  Hopefully, I can make this work.

Dale

Title: Re: AC plenum valve
Post by: 67CruiseMaster on July 15, 2021, 08:28:48 PM

Instead of allowing outside air into the interior of your car, that flapper just uses inside air to recirculate.

Scot