Door relief valve
 

I just put new seals all around in my '67 C20 and now it is really hard to close the door unless the window is cracked!

Is it possible to retrofit a relief valve from the later model to my cab? What would be involved in that? Where does the air go?

TIA

Re: Door relief valve
 

I'm going to start off by saying I'm jealous that you have your cab that well sealed. How about cracking the cowl vents just a little? Anyway, I don't see why you couldn't install the valves from a newer truck, just have to cut the right size hole and screw it in.

Re: Door relief valve
 

There's no reason that it couldn't be done, but you could also install one from a '72 in the door jamb. '72s had a black plastic vent just below the driver's door striker in the cab.

Re: Door relief valve
 

71 and 72 had the vent. It was one of the changes they made in 71 to the cab, the others included the square hole for throttleand the raised pad for hanging rear view mirror (1 year only). You can get a used vent from one of these trucks, trace the outline of the backside and using a cut-off wheel cut the outline out, shape up with a square file and you have a cab vent. Be sure to use tape and tape off the areas around the cut so sparks dont screw up your paint. Hope this helps.

Re: Door relief valve
 

So does the air come from the inside of the cab, through the valve, and into the space between the door and the jam? I'm just trying to figure out how it works.

Thanks for the responses!

Re: Door relief valve
 

Yep, you got it!