astro-ventilation

[jmp]

What is it and how did it work? It's not simply just open air ducts on the rear deck, right? There's some sort of mechanism opening those ducts, correct?

How do I check to see if it is working?

 

[JohnZ]

Depends to some degree on the year, but generally they're vacuum-operated and open when the heater control is in "Vent" position to provide an exit for air that enters through the dash outlets; they're blocked off completely on cars with A/C. If you look up under the deck area, you'll see a vacuum can on one side that moves a shaft with the flapper doors attached to it. Many don't work due to corrosion, broken vacuum hoses, or a failed vacuum switch on the side of the heater control.

 

[jmp]

Now that I know what astro-ventilation and how it works, I've decided to fix mine. Partly b/c I'd like everything to work and partly because water is leaking in from the rear-deck vents.

So, I started by starting up the vette and playing with the heater controls. The doors didn't shut. After some minor contortions, I managed to get myself wedged up in the back to get a good look at the vent doors. First thing I noticed? Boy, they sure are rusty! In fact, pretty much rusted open. But a little bit of WD-40 and elbow grease got them moving again.

Next, I looked at the vacuum actuator (?? Is that what it is called?) and noticed that something was missing -- the vacuum hose! The actuator itself seems to work -- at least, if I close the doors and plug the hose connector, the doors stay shut. So it maybe that all I need is the hose.

Anyone know how to route the hose? I'll also have to figure out where the vacuum source is, I guess!

Finally, given the shape of the duct doors, I decided to take them off. Got the right one off, but the left has two really rusted screws with stripped heads!

Second question: anybody know where I can find replacements for these doors? They don't seem to be available from Ecklers or Mid America -- still have to check the other distributors. If I can't find replacements, I guess I'll have to clean the doors up best I can, and get some generic seals for them.... and a length of vacuum tubing!

 

[JohnZ]

Corvette Central and Dr. Rebuild sell all the seals and fasteners, but I haven't seen any suppliers that sell the doors themselves; better clean them up and re-use them - I don't think they're reproduced. The vacuum source for the actuator is a vacuum switch on the passenger side of the heater control, and the hose routes under the carpet from there to the actuator.

 

[jmp]

Thanks JohnZ.

Turns out Ecklers does have the seal kit too -- I just didn't see it in their catalog (only online). No doors though... And no hose.

I'll poke around and see if my vette still has the hose under the carpet somewhere.

Hey, how soft are the drain tubes supposed to be? Mine are very soft, to the point of getting squished where they exit the vehicle. Might be another reason I've got a leak here.

 

[ChuckG]

The "piping" to the rear actuator is actually a combination of metal TBW type pipe and rubber hose. The metal pipe runs along the passenger side console....behind the passenger seat...up over the "glove box" area, and then under the carpet in the rear. You might have pin holes in the metal pipe. You'll have to pull back the carpeting in those areas to see it. Hope this helps. As others have said, the seal kits are available. They're thick foam like devices which glue over/on the flapper doors. Chuck