JHC928

This 5mm white tube is hanging down behind the instrument pod in the footwell. I have no idea where the open end is supposed to connect nor do I understand its function.
As always, thanks in advance for your feedback!





Regards,
John
1981 928 Chiffon White over Cashmere A/T (127k)

Jerry Feather

That's your sunroof drain. It drains on your right foot to let you know to turn on your WS Wipers.

Just Kidding. I have not a clue what it is.

Jerry Feather

Well, actually I have a tiny clue. Because of its location, and its size, I suspect it is a vacuum line that should be connected to something on your HVAC system nearby.

worf928

Post the model year of your 928.

Jerry Feather

He did. See his signature.

worf928

Awe h3ll. I missed that first time around. Thought I looked twice too.

My first thought was that it was the vac line for the hot water valve (which should be white.) But, it's way too big for that.

There are other (seemingly) vac lines in the second picture. But they're all too big. So, either they've been replaced with Silicon or it's a 'early 928 thing.'

Wisconsin Joe

I think it's for the HVAC, as noted above.

Does the airflow change when you move the 'direction' slider? (does it work correctly?)
Is there vacuum on that tube? (it may be there only in some positions of the slider)

JHC928

Jerry was close with his first response, but my sunroof actually drains into the passenger side footwell

An HVAC vacuum line does make sense. I will experiment a bit and report back if I can figure it out.

Regards,
John
1981 928 Chiffon White over Cashmere A/T (127k)

worf928

There is a vacuum manifold bolted to the base of the torque tube tunnel just under the air box to which that line should connect if indeed it is an HVAC line.

WSM has pictures and diagnostics.

I’d post a picture of how it all connects together on a bench, but I can’t, anymore, without jumping through hoops.

JHC928

Thanks worf928! I found the vacuum schematic in the WSM. Now i just have to figure out how to read it and follow the Weiß tube

Regards,
John
1981 928 Chiffon White over Cashmere A/T (127k)

worf928

It seems that for pre-84 that line may have once been yellow.

JHC928

I've attached the vacuum schematic from the 1981 WSM. It appears that my dangling tube should be attached to the footwell flap which is perhaps exactly what you suggested previously....
"There is a vacuum manifold bolted to the base of the torque tube tunnel just under the air box to which that line should connect if indeed it is an HVAC line."

Regards,
John
1981 928 Chiffon White over Cashmere A/T (127k)
P.S. Since we both live in New England, can I leave this car with you to sort out the few hundred issues that remain?

worf928

Beware that my knowledge and experience with pre-'87 928s is suspect. The vacuum manifold on pre-'84 may not be where it is on later models. And apparently the colors changed...
I'm booked into mid-2021. But, I'm happy to advise. If you end up in the North-of-Boston area you are welcome to stop by.

Auto-Didakt

Hi, it looks like you have the manual airco, because of the bowden cable in your pictures. The schematic is for the automatic airco with the solenoids.
If you have the manual one, i can have a look for you in my literature.

Gr, Joes

JHC928

Thanks Auto-Didakt! I do indeed have a manual HVAC control head. I will stop looking for solenoids
Please let me know if you have any guidance.

Regards,
John
1981 928 Chiffon White over Cashmere A/T (127k)