1977 plenum valve

[Jim A.]

I am assembling the firewall on my 77 coupe and once again looking for help. Can anyone tell me where the plenum valve shown on drawing B01 to B12 sheets 53 and 57 is located. I can't recall and didn't take a photo of it's removal. I hope that I don't have to remove the heater/blower box to install. Attached are photos of the restored valve and my car firewall.Plenum valve actuator.jpgInterior firewall.jpg

[John S.]

Re: 1977 plenum valve

Jim, from your pics it looks like the actuator is for the fresh air intake control on AC equipped cars mounted in the passenger side foot well just above the plastic kick panel. Pretty sure you do not have to remove the heater box to install. See attached, hope this helps, good luck.

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[Jim A.]

Re: 1977 plenum valve

After looking more closely at the assembly manual and my vacuum tubing, I think the plenum valve is mounted in the plenum and works in conjunction with the recirc valve which is located where your pictures show a pneumatic actuator. My plenum valve is actuated from a green striped hose that comes through the firewall and is then routed via a single hole gromment back into windshield wiper tray. It is long enough to go under the right plenum screen. See pictures. I should have put it in before installing the heater/blower assembly. I think I will have to remove the heater/blower assembly to install the plenum valve.Plenum valve tubing routing.jpgPlenum valve tubing connection.jpgActuator and vacuum hose routing.jpgPlenum valve drawing.jpg