Just a reminder....I am the originator of this threaed.......
The car is back from the shop. All new radiator, hoses, water pump, t-stat, heater core (installed, not hooked up yet), v-belts, side and front head hose flanges, pressure cap. I purchased a new fill bottle to install myself. It's in the parts bin for use at a later date.
I did a quick cold pressure test to see if any combustion gas might be leaking into the coolant. I used a rubber glove over the fill bottle neck and it remained limp, no gas pressure detected. I'm going to check it with the U-View Gas Tester when I get one. Which I did. I'll skip the details which I will post under separate heading. The results were negative for combustion gas leak. This confirmed what the shop tech told me.
Apparently there was no head damage, at least at this assessment. The new flanges stopped the leak that I though might be the head gasket. Good and dry now. The drive home was uneventful although the temp gauge acted flaky. It didn't register what I expected (only about one bar off the low point while driving on the freeway. Then it dropped way low .....??? Of course, that made me a little anxious. But on arrival at my place the engine seemed fine, the hoses were not extremely hot to the touch and everything looked A-OK.
I replaced the voltage stabilizer which supplies working voltage of 10 volts for the gages and, I'm guessing, the idiot lights. All gauges and lights, except the glow plug light, working normally. I'll cover some details in another posting.
Now for some revealing photos.......of the prime suspect in this adventure, the small diameter hose that runs from the top radiator hose to near the top of the fill bottle. Yes, it was plugged and was probably the cause of the overheat/heater box disaster.
Here is the hose, sliced and diced. Right thumb near the orifice in the hose and left thumb near 23 years of sludge buildup!!!!! Wow!! and more down the tube, I suspect. This shows what so many have written about in this thread and what I felt as hard lumps down the hose.
Here is one view of the orifice which was about and 1 1/2 inches from the fill bottle:
Another. Notice the crud. It could plug the small hole by itself if it wasn't for the pressure:
It makes me wonder why they have that orifice in there at all????? Maybe there would just be too much flow into the bottle.
And, as you all have pointed out, that little hose now just gushes fluid even at low idle.....nice and juicy. It makes a good "canary in the coal mine" for the presence of coolant crud. I intend to keep it clean.
Thanks for all of the tips.