Positive Cab Ventilation

[AcampoDave]

A while ago while in the junkyard, I noticed that more modern pickups have oval shaped air check valves in the back of the cab below the bedline. Apparently, they have some kind of a flapper door to let the incoming air from the ventilation system escape thru a grated cover.
Has anyone ever tried installing these on their classic truck? It seems it would go a long way to improve the air flow of the heater and kick panel vents and I surmise it would reduce the wind noise when cruising with the windows up and vents open.

[The Rocknrod]

Yes about halfway down the page "Rear Cab Air Vents" - https://talk.classicparts.com/thread...p.13928/page-2

[jayoldschool]

Vents like that are the reason that vent windows disappeared.

[Steeveedee]

I remember the ads from Chevrolet when "Flow-Thru Ventilation" was introduced. The guy talking showed how cigarette smoke was cleared from the car by that flow.

[AcampoDave]

Did Chevy begin doing that on the squarebodies?

[Steeveedee]

I don't know about the trucks, but the cars got them in '71.

https://www.autoweek.com/car-life/cl...vrolet-impala/

[mike's1965]

My mom had a Grand Am and saw something like what you describe near the frame of rear driver's side door.

On that car I figured it was to let the air push out when shutting door, with window rolled up.

Could this thing you describe be to displace air of a closing door?

[SkinnyG]

The squarebody vents out the bottoms of the doors.

[verdell]

I used to follow LakeRoadster's build years ago and considered doing the same thing after removing my bed and redoing the wood. I think I ran out of time and never did look at it again. I still have the rear cab vents I removed from a couple of different model trucks.

[forestb]

I have thought of doing something like that so that I could close my doors more easily. My doors shut great with the windows down but not as easily will them shut

[forestb]

I also noticed when I shut my doors I notice that the roof shakes a lot. I wonder it that is because of the air not having anywhere to go.

[The Rocknrod]

Originally Posted by forestb

I also noticed when I shut my doors I notice that the roof shakes a lot. I wonder it that is because of the air not having anywhere to go.

That could very well be if your cab is sealed up well.

[68panelman]

I've always been in the habit of opening the door, roll down window a few cranks, enter cab, close door. Depending on the season, roll all the way up, or down.

[The Rocknrod]

Originally Posted by 68panelman

I've always been in the habit of opening the door, roll down window a few cranks, enter cab, close door. Depending on the season, roll all the way up, or down.

What about when you leave?

[68panelman]

Originally Posted by The Rocknrod

What about when you leave?

Same thing, only reversed. My kick panel vents being open probably aid in cab pressure relief.

[forestb]

Originally Posted by 68panelman

Same thing, only reversed. My kick panel vents being open probably aid in cab pressure relief.

yah it probably doesn't help that I put speakers where my kick panel vents used to be.

[forestb]

The guy that installed my weather stripping on recommended that I leave the section out that runs along the bottom of the door. I wonder if that will help. But then I wonder what problems will run into if I do. Especially wind noise. The only reason I am so concerned is because I keep on having problems with the bondo in the roof cracking.

[racecougar]

I did this years ago to get the doors to close like a modern vehicle. See this post in my build thread: https://67-72chevytrucks.com/vboard/...&postcount=645

[forestb]

Originally Posted by racecougar

I did this years ago to get the doors to close like a modern vehicle. See this post in my build thread: https://67-72chevytrucks.com/vboard/...&postcount=645

Good Idea. If only I didn't have my speakers located there.
I don't think it would work to put them in the door jams sense the gasket is on the inside of the jamb.

[racecougar]

Originally Posted by forestb

Good Idea. If only I didn't have my speakers located there.
I don't think it would work to put them in the door jams sense the gasket is on the inside of the jamb.

If you place the vents in the rear door jamb, outside of the weatherstrip, it absolutely will work. Take a look at many vehicles from the '60's and '70's; that's a common location for the relief vent.

I didn't go that route, as that is where my speakers are hidden.

[forestb]

Got it. I was thinking of it backwards. So that the air would be pushed inside the cab.

[forestb]

I think I need to install something like this or else the bondo in my roof will continue cracking. I can see the roof shake every time I shut the door with the windows up