1966 interior vacuum leak

[David Flores]

I have a 1966 Ford Thunderbird and I just recently started hearing a hissing noise in the interior this only happens while the car is running and I'm sure it's a vacuum leak but I don't know how to go about looking for it or where to start I'm certain it's in the interior because I hear it in the center near the radio I know it is not the radio because when I turn the car to the on position there is no hissing it is only when the car is completely running and goes away the moment you turn off the car please help thanks

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[didi]

• Hey guys I have a 1966 Ford Thunderbird and I just recently started hearing a hissing noise in the interior this only happens while the car is running and I'm sure it's a vacuum leak but I don't know how to go about looking for it or where to start I'm certain it's in the interior because I hear it in the center near the radio I know it is not the radio because when I turn the car to the on position there is no hissing it is only when the car is completely running and goes away the moment you turn off the car please help thanks

sounds like the vacuum hose on the rear vent switch came off or broke, if you take the center console side panel
off, you can get to it, good luck!

 

[Rlucky63]

Close and open your rear vent and listen if the hiss still there. Usually, it will stop at an open position. Mine is doing that too, I just let it open!

 

[Azfamily]

I have a 1966 Ford Thunderbird and I just recently started hearing a hissing noise in the interior this only happens while the car is running and I'm sure it's a vacuum leak but I don't know how to go about looking for it or where to start I'm certain it's in the interior because I hear it in the center near the radio I know it is not the radio because when I turn the car to the on position there is no hissing it is only when the car is completely running and goes away the moment you turn off the car please help thanks

You might check heater a/c controls several vacuum lines in the controller.

 

[Drewstoy]

I have a 1966 Ford Thunderbird and I just recently started hearing a hissing noise in the interior this only happens while the car is running and I'm sure it's a vacuum leak but I don't know how to go about looking for it or where to start I'm certain it's in the interior because I hear it in the center near the radio I know it is not the radio because when I turn the car to the on position there is no hissing it is only when the car is completely running and goes away the moment you turn off the car please help thanks

There are a mass of vacuum hoses operating everything from heater control to power door locks plus the rear ventilation system in my case former owner removed center top plate to replace radio and disconnected a bunch of them my son likes a challenge and eventually figured out what was what
A detailed schematic would have helped don’t know if anything exists

 

[Josh]

I have a 1966 Ford Thunderbird and I just recently started hearing a hissing noise in the interior this only happens while the car is running and I'm sure it's a vacuum leak but I don't know how to go about looking for it or where to start I'm certain it's in the interior because I hear it in the center near the radio I know it is not the radio because when I turn the car to the on position there is no hissing it is only when the car is completely running and goes away the moment you turn off the car please help thanks

It sounds like the heater plenum. Does it hiss in all selector positions?

 

[67 Thunder Chicken]

I Don’t Know if this Help or Not, But On my 67 tBird I Had Same Leak Sounded Like Coming From Radio Area, I Took Side Panel off Of Center Console And Found that my Vacuum Hose had Come Disconnected From My Cruise Control Switch, Prob Not your Issue but Id Check it Out, Hope info was Useful.