[Don Smith]

Hi guys and gals. I picked up my 88 S4 last April, and with our beautiful summer, so far, I did not have a necessity to use my heater too often, but, recently, I noted that there was no modulation of heat. It was always full heat, no matter where the temperature was set.
I checked out Dwayne’s garage, and decided to go hunting... put the Mity Vac on the splitter towards the firewall. The pump bled down immediately.Umm, o.k. Under the console, we go. As per his write up, removed the under trays and carpets and got to the “ manifold” where the vacuum hose from the firewall goes to. There was my problem. The incoming hose from the brake booster was off, disconnected. Pushed it back in , and everything works properly again. You’ve gotta love a simple easy, no cost, fix.Here is a photo that Dwayne included, to show the different vacuum hoses.
Hope this helps someone.
Cheers
Don

[linderpat]

Thanks Don - I have this problem too, altho I suspect my fix will not be anywhere near as easy as yours was!

[Don Smith]

Sometimes you get lucky. My foray into the guts of the car, lasted less than two hours. Dwayne’s procedure was easy to follow. If I ever meet him, I owe him a beer.
Have a great weekend Linderpat.
Cheers. Don