1964 Bird HVAC control unit ?

[ak7an]

Like I stated in a previous post have the dash all disassembled to troubleshoot a few issues. One issue I am working on is my HVAC controls. Nothing in the system will function quite right, everything is trying to open and close as I change the control position. I am only able to hold between 10 and 11 inches of vacuum, and whwn Increasing RPM's a bit my test gauge will go to around 17 but fall back to around 10 at idle. Tested the check valve and it is working as intended. When I disconnect the HVAC control at the fire wall I get and hold 18 inches. So here is what I did to try and see where I was losing vacuum.. I disconnected and plugged off all the small lines that go to the vacuum actuators.. still same, can only build and hold around 10 inches. So to me it would seem that the control unit itself is leaking somewhere. Is this a common issue with these old units? Are these repairable, or will I need to find a working replacement?
Thanks
Ed

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[inspector]

You may have a leak in the line from the firewall to the actuator. Disconnect the vacuum line from the actuator and plug it and then check your vacuum.

 

[ak7an]

I will do that, diagram shows 2 lines going to control, I know one goes to the temp selector, is the other hooked to the black port on the top of the controller?

 

[ak7an]

No leaks in the line thru the firewall. I took the control unit out to see if maybe I could take apart and clean any dirt and debris that might be causing an issue. Started taking it apart and when I started to loosen the screw that is at the pivot point down to the selector device, there was a nice loud "click". That seemed to be overtight. Tested the unit using the shop manual troubleshooting guide and it tested out fine. The only issue that it still has is the temp regulator seem to have a leak.. Does anyone know if there is a replacement or a work around for that?
Thanks
Ed