The squeak was located!

[Toploader]

At first I assumed it was Freon, but now I think it was anti-freeze mist/haze.

Does the smoke smell like coolant?

Never heard of this before...

[Toploader]

Sly, so by virtue of moving that slide to higher temp setting, I get the heater core to circulate coolant, and mix with R134 at the registers ion the dash?

I've seen this before... it was coolant and there was a pinhole leak in the heater core.

[Toploader]

Why does throttle position effect the force of air coming out of the panel registers? (engine load)

[HiFiMerc]

Vacuum is related to throttle position. HVAC runs on vacuum.

[mobydick]

Sly, so by virtue of moving that slide to higher temp setting, I get the heater core to circulate coolant, and mix with R134 at the registers ion the dash?

Coolant is always going thru the heater core. The temp slider just blends cool/hot air or is full cold or full hot.

[mobydick]

Why does throttle position effect the force of air coming out of the panel registers? (engine load)

For safety reasons when there is a loss of vacuum the hvac system defaults to the defroster setting. If you have ATC the system is vacuum controlled and if you have a loss of vacuum somewhere it will shift everything to defrost.

[gadget73]

yep, vacuum leak somewhere. The air doors are shifting around on you. It may even be a bad check valve, and not an actual vacuum leak. It will do the same thing.

[Toploader]

Gadget, per your suggestion, I removed the plastic TBLOS housing, tossed it in the trash, and put a hose in its place from intake up to the heater core. I also plugged the two vac lines.
When you say bad check valve, where is it locted and what does it look like?

[Toploader]

Yup, I have ATC!

For safety reasons when there is a loss of vacuum the hvac system defaults to the defroster setting. If you have ATC the system is vacuum controlled and if you have a loss of vacuum somewhere it will shift everything to defrost.

[Toploader]

In the winter I never see this fog/mist coming out, save for a little fog on the windshield, heater core needs to be changed, but not a big priority now.

Coolant is always going thru the heater core. The temp slider just blends cool/hot air or is full cold or full hot.

[gadget73]

the check valve is on the vacuum tree, center of the firewall right behind the upper intake. I think its the top item. Should be 2 small hoses going to it. One goes to the soup can, one goes inside the dash. That has to work as a one-way valve. The line to the soup can, and the soup can itself also need to not leak.

[Toploader]

I found a picture of it, I see the two small inlets for the vac hoses, but the large vac line that attaches at the top..........where does it go to??

[gadget73]

the top of the vacuum tree? The fat line goes to the upper intake. Thats your vacuum source.

If you mean on the check valve, the larger connection goes to the vacuum tree, the two small ones are common, and go to the HVAC controls and soup can. Basically its just a check valve with a tee built in. There is usually only about an inch of hose between the vacuum tree and the check valve, just enough to connect the two parts together.

[Toploader]

Ok then, onward and upward........have no idea where that is from, but remember it from high school a million years ago
Thankfully a new valve is only 8 bucks!

[gadget73]

yeah, not spendy. Make sure the soup can holds too. They tend to rust out at the seams. Last I saw one priced, it was like 40 bucks. You can retrofit a plastic one from a later model, or really any other vehicle if you want. The sizing and dimensions aren't critical.