Rod Handsfield

How does one go about this repair? Has anyone on the list done this. Source for replacement dash vent vacuum pod? thanks, Rod

jcorenman

Just did this (getting ready for Texas!!). The best writeup I found was Dwayne's, here:
https://rennlist.com/forums/928-foru...re-w-pics.html

The common problem is vacuum leaks caused by torn diaphragms, Dwayne explains how to disassemble the actuators and you can get replacement diaphragms from Roger (ROG100 here or www.928sRus.com).

It takes time to get into the console, so while you are there do both the center-vent and the footwell actuators.

Cheers, Jim

P.S. What year? The airbag models are a little different, the glovebox still has to come out and there is one bolt that is hard to get to, above the glovebox area (same general area as the pre-airbag cars, just more stuff in the way).

Alan

For just the central dash vent I believe you can access it well enough if you just remove the HVAC head unit, AC switch/central lock panel and Possibly also the radio/headunit... if not just take off the driver side console side panel & you should have adequate all round access. depending on year there may be one or 2 vacuum diaphragms. For the dual diaphragm versions ('80-'83 models) I believe the diaphragms are NLA as individual replacements.

Alan

Rod Handsfield

Thanks for the input. It's a '91 S4.

Alan

OK Rod - then what I thought you were asking about doesn't even exist on your car.. your central vent (console vent) is just manually controlled with the up down **** on the right - correct?

Earlier cars had vacuum control of that vent.

So what flap are you looking to R&R? is it the secondary mixing flap inside the vent? (inside the HVAC unit) - that is substantially harder to get to...

Alan

Manfred

Dwayne's post is great and that's what I used when I did mine. With a '91 S4 though yours will be a bit different because of the airbag. Mine's a 91GT so this is what I can tell you:

The last bolt you need to remove is not easy. It's an 8mm bolt that holds the right side of the center console to the passenger side of the dash. Once the glove box is out you'll have to get on your back with your feet over the passenger seat and your head in the footwell--you'll need a good light to shine up in there. Look at the seam where the right side of the center console and the passenger side of the dash meet from the outside--that will give you an idea of where to look once you get upside down and put your head in the footwell. It also makes things easier if you get all the AC tubing that connects to the glove box out of your way--it's just a press fit and pulls off.

Many people do not put the bolt back in once it's out due to difficulty in replacing it and if you ever have to get the center console out again then you won't have to worry about it. I was able to get it out but I used my wife's small hands to get it back in while I aligned the center console to the dash from the outside. You do not have to take out or do anything to the airbag.

Good Luck,
Dan

jcorenman

Alan, that was the one that was inop in our '90GT. It is a "comb" flapper that reduces airflow through the center-vent when the floor or dash-top vents are open, and also depending on temperature IIRC. When the diaphragm splits then the center-vent still works but the air flow is pretty wussy. You can pull the center-vent louver assembly and peek in to determine whether it is working or not, before taking the big dive into the console.

I was able to get to that "corner bolt" out (and back in) with a 13mm u-joint socket (the kind with an integral u-joint) and a long extension.

Ed Scherer

See also:

• "Weird sound from dash, HVAC ?"
• "A/C Vacuum problem. Getting close, please help!!"
• "Need help replacing vacuum actuator"

Includes some more photos and instructions to get you through this.

Manfred

https://rennlist.com/forums/928-foru...ole-screw.html

A post with pics regarding that last bolt...

As you can see from the pictuures in the post, when you replace it the trick is getting the screw in the clip and getting the threads started.