Low and behold two of the vacuum connectors (boomerang shaped) were slit at the seat of one of the yellow valves. For the bottom one in the picture...both were slit on this yellow valve.

Replaced these connectors with hose pieces (freebie from dealer) but the problem still remains.

Attacking on both fronts, as I have the glove box off in anticipation of changing that valve in there, also working on stereo while I'm at it.

Question though, why the discoloration in the bottommost valve nipple? The others aren't like that. Looks more like burning than dirt.

Trying to figure the sequence of the breakdown of my system...did the slit connectors cause a breakdown of other parts in the system (e.g. valve in glove box?)

So if I've still got hot air out the sides, and have changed the heater control valve and corrected connector leaks, the valve in the glove box is the next logical thing to try?

...these yellow deals are thermo-vacuum valves? Is that right?
Is that burning indicative of failure and I should replace it?

Thanks in advance for your past and future assistance.
mike

Attached Thumbnails

 

__________________
1993 190E 2.3 California