Pressure relief valve on door jamb
 

I am painting my 72 GMC and when I took the relief valve off the door jamb I noticed that the steel at the bottom of the vent is slightly bent in, not flat. I dont know whether it is supposed to be that way or not, I looked at the other door as a reference and just noticed it has no relief valve on the jam. Now I have two questions, is the slight bend under the valve stock and why is there no valve on the passenger door? It seems like both should have one.
Thanks for any info! Aaron

Re: Pressure relief valve on door jamb
 

I never noticed mine being bent. But only 1 relief on my 71 GMC (DS) also. If I recall correctly 75 and newer had 1 per door.

Re: Pressure relief valve on door jamb
 

71 was the first year for the valve and one of the ways to determine year of your cab, there are others as well but will not go into that. They only use the valve in the driver's side and it should be flat under the valve. The valve also gets a thin rubber oring around it as well to help seal against the "b" pillar.

Re: Pressure relief valve on door jamb
 

It's all tied in to the fuel tank vent/evap system. Nothin' to do with venting the cab.

Gary

Re: Pressure relief valve on door jamb
 

It actually vents the pressure from the door when it closes, it makes it easier to close the door. It makes a big difference, my 69 doesnt have one ofcoarse and the door is much harder to close, specially with the windows closed.

Re: Pressure relief valve on door jamb
 

I am i missing something.I never herd of p.r. valve on the cab.what is it for?whats does it look like?Any pictures?My '72 doesn't have one.

Re: Pressure relief valve on door jamb
 

Thanks everyone! I will flatten out the area at the bottom. Aaron

Re: Pressure relief valve on door jamb
 

If you have a 72 it should be on the door jamb on the drivers side, it's around 6" tall, plastic and has a rubber one way flapper type valve on the inside. Its there to make the door close easier, without one it's much harder to close the door, my 69 doesnt have one and its much harder to close the door.

Re: Pressure relief valve on door jamb
 

This is correct. It is not tied into the fuel tank or EEC.