[michaelroy]

Does vacuum operate the cable that switches the controls for heat A/c Vent etc? Does it actuate a door in the heater core box? I can't operate it with my hand and there isn't very much vacuum coming from the manifold
65 389 tri power w/ air.
Planning to replace all the hoses and follow hose routing listed in the resto manual. None of the hoses have colors. A better diagran would help if any one has one.
Thamks , Mike

[Old Man Taylor]

I don't know about A/C cars, but my '64 w/o A/C is direct cable connected to the heater box door. Over time it gets very hard to operate.

[michaelroy]

tHANKS, The manual says that 64's had 3 cables to operate the controls and temp. My set up has only one cable for temp, and vacuum is suppose to do the rest.

[aceaceca]

I redid my whole system a few years ago. There is a vacuum motor that opens a flap to direct air to the windshield for defrost.
There is a vacuum motor under the hood with 2 lines on it. It controls a flap that allows air to come in thru the cowl on the
passenger side. This is for outside air. When closed, the air is recirculated from inside the car. You can check the defrost vac motor
by checking that air is going to the windshield. The under hood vac motor is often broken due to engine heat and bonking by mechanics.
With the cowl vent off you can stick your hand in there or use a mirror in the cowl to see the flap move. A big problem is if the AC
duct leading to the evaporator is plugged with 55 years of leaves. To get to the back side of it the fender well must come off.
There is also a huge rubber gasket, not reproduced, which seals the evaporator to the body. If you have the heater box out of the car you will see
the front side of the evaporator. I think I posted some stuff about doing my system. See if it here somewhere.

[aceaceca]

Found it. My 2 cents worth.
http://forums.maxperformanceinc.com/...d.php?t=796436

[michaelroy]

Thanks ace, that is a lot to digest. I will go over your post item by item, I found today that there was little to no vacuum coming from the center carb(tri power) to the valve that operates the various functions. Had plenty of vacuum from the front carb, so I switched the lines to the valve.
When I operated the lever for the various functions there was no movement to the lever on the htr. box.
Don't know about vacuum motors??????

[james66GTO]

I think what Ron is referring to are the two large disk shaped vacuum actuators. If i recall correctly one mounts on the blower housing (engine side) and the other on the heater box (interior cabin side) 1964 used cables for comfort control and in 1965 they changed to a vacuum system. It's a little complicated/confusing but it basically comes down to a couple of diaphragm actuators, a couple of check valves, adequate engine vacuum and a whole lot of vacuum hoses. One of the key things for success is making sure that every part that is supposed to move is properly lubricated. Eric

[michaelroy]

Thanks James! I have both of those in the system. They are like you said actuators. Will start on seeing if they are functional.
Hope I don't have to remove the heater box. That would be a real PITA.

[james66GTO]

Pretty sure there is a 3rd actuator on top of the heater box, middle, near the firewall. That's one's got to be a miserable one to get to! Best of luck!

[aceaceca]

The slide on the dash is a cable operation for hot/cold . It opens or closes a door to divert air through the heater core or not.
On cold the door isolates the heater core. Any other position it is a mix. Part through the heater core and part not. I am drawing
a blank on the 3rd vacuum motor but it will come to me. Defrost, fresh air from the cowl, and ?
All the padding on the doors is long gone. I opted to leave it all off. Not critical.