65 vacuum canister/hose for AC/heat

[jimfox13]

My 65 (with AC) is having a heat issue. I recently discovered that hot air was flowing in through the defrost vents and the floor vents - the faster I drive, the more powerful the flow. If I turn on my heater, the fan works but the airflow goes to floor and defrost vents no matter what I turn the controls to. At roughly the same time, I discovered that the small hose from the vacuum canister which goes through the firewall was just sitting in there loose, connected to nothing. In the picture, I coiled it up on the canister.

My assumption is that hose connects to a junction box which supplies vacuum and controls all the vent doors for my AC/Heat system. Is that true? If so, do I have to remove the whole dashboard and the heater box to reconnect that hose? (I’m not super mechanical and that sounds very difficult)

Any knowledge, experience, or advice is appreciated.

Thanks,
Jim

[paulr]

I don't see a heater valve in your pic (the yellow cad thing in my pic). It should be in the same location; maybe it's hiding under the fender brace and I can't see it. Anyway, if it's missing, or not hooked up, that's a red flag.

Aside, looking at your photos, you have issues. The vacuum canister in the pic amounts to a system leak if that's an open hose coming from it (can't quite tell), but basically, it's not the reason you have heat all the time. I also see past attempts to reconfigure the vacuum paths which suggest attempts to solve problems that haven't worked. This probably all got done before your time. The fact that blower air comes from floor vents and dash vents suggests that your console control head is mis-plumbed or might need cleaning up. This could also be a thermostat issue, but let's wait.

Don't get down. Eat an elephant one bite at a time. First two bites: 1) Look around for/hook up your heater valve. 2) close off loose vacuum hoses, if any.

[jimfox13]

A fellow Seattleite! I found the heater valve - sitting solo with nothing connected to it all. I’ll start by trying to get that hooked up. Thanks!

[jimfox13]

I've hooked up the heater valve but can't tell if it is working - there isn't a vacuum line coming from the firewall to connect to it. Any ideas on how to hook up that vacuum line?

[paulr]

there isn't a vacuum line coming from the firewall to connect to it.

That's a problem.
This confirms, if you want to hear it, that the previous owners or their mechanics really hacked up the HVAC vacuum paths and now it's up to you to live with it or do something about it. It's definitely doable, and fairly easy, but very time consuming.

That vac line from the top of the water valve passes through the firewall to the thermostatic control valve, and is absolutely necessary. There is a false theory floating around the Tbird world that you can bypass this valve (if it fails) by just sending vacuum from the dash directly to the water valve and sealing off the TCV. Wrong. In your case they found out that didn't work, so they went one step stupider and removed the water valve, and you got stuck with perpetual heat, which may have been fine if you bought the car in winter. Not your fault. Pardon my rant.

There are two ways into the dash--remove the dash, or cut into the firewall--both ways are slow. I'll bet a Top Pot doughnut it will not be the only messed up vacuum line you'll find.

I'll send a PM in the next moment with further info. Maybe I can help get your heat turned off for the summer.

[jtschug]

I'm not sure, but I don't think you have to go full dash removal. There are a few different ways you might be able to get to the vacuum lines:

Remove the dash trims and the A/C vent and push the belows back, and maybe you could see where the vacuum hoses come through?

Another route would be remove the blower motor, then you could unscrew and pull down the thermostatic valve which, if memory serves is where the hoses for the heater valve and the hose for the reservoir attach.

[mnpetri]

IIRC, you can access the vacuum connections with the radio/center part of the dash off?
There is a valve there with a BUNCH of vacuum lines (color coded), with my car (65 w/AC) nothing worked until that was all corrected and vacuum leaks eliminated.
Good luck!

[Rt.146]

Vacuum canister, heater door, driver side

There is a vacuum canister for driver's side heater vent door, removing and replacing the canister having slight contortionist ability helps, it is the hook up of the canister and door lever, putting "something" to secure the two is the challenge, my car had A/C, the evaporator is still in the car, that makes for a difficult time space wise to secure the canister and heater door, I'm going to try a push nut 3/16" all else has failed. The push nut worked, though , some thoughts, was the car built around this canister, was the evaporator put in after the canister, did Ford use trained monkeys with their small hands to connect the door to the canister?

[SBurney]

I don’t know what kind of time you want to put into the car, but if you’re looking for a hobby you’ve found a good one. Taking the dash out isn’t difficult, it just requires time and patience. If you do it, take more notes and photos than you think you’ll need because they’ll come in handy. You can replace every bit of the dried out vacuum hose that’s back there, replace the actuators that no longer work, and it’s a good time to rebuild and repaint the steering column, too.

As for the temporary fix, I’m guessing that Paul’s solution involves installing a valve in the coolant line going to the heater core. Open in winter, closed in summer, easy to do-there’s one in my car for the same reason and I’ll probably even leave it there even though I’ve fixed the entire system. I installed a new heater core, but it’s nice to have a valve in case it gives out again.

Hey, replacing the heater core is something else you can do with the dash out. Again not hard, just a matter of time and patience.

[Alan H. Tast]

As for the temporary fix, I’m guessing that Paul’s solution involves installing a valve in the coolant line going to the heater core. Open in winter, closed in summer, easy to do-there’s one in my car for the same reason and I’ll probably even leave it there even though I’ve fixed the entire system. I installed a new heater core, but it’s nice to have a valve in case it gives out again.

That's what I've resorted to with my '63 hardtop when the heater core/valve decided to 'let go.' An inline shut-off valve between the outlet in the top of the intake manifold and the connection to the heater core inlet. Your local auto parts store should have one with 5/8" inlet/outlet that you can splice into your heater hose.