Zeb and I got back to the New Beetle AC today (he wanted to help out an eldery lady who is on hard times.)
We took out the old compressor and drier, found the black death had gotten up into the condenser, but not too bad. Not out of the drier, and not out of the suction hose. Apparently there was not enough oil to carry the crud too far out of the compressor.
We back flushed the suction, discharge, and condenser with Naptha, and then with acetone, using a liquid then air blast, repeat until a white filter cloth showed no black and no metal. Then purge with air for 20 minutes.
Replaced the drier, and the compressor (cheap chinese stuff).
Tried to draw a vacuum and lost it. It looked as if an oring or seal turned. So gave it a quick shot of refrigerant (less than an ounce), to pressurize the system. Then we were able to draw it down and pull a vacuum, held 29" for 40 minutes.
Then we added about 700 -750 grams of R134a.
It was actually running too cool, air temperature down around 35 degrees. This could cause icing on long trips, but she does not do long trips, and it will be great around town. The too cold air/ too low suction pressure is probably a function of the compressor control valve.
The thermal expansion valve seems to be working fine, providing plenty of flow.
Total cost was about $375, for parts and flush liquids. Motorinar, here on the site, donated $75 towards the job, so it only cost the lady $300 in parts.
Since we essentially did the job twice, we had 24 manhours, 12 clock hours in this effort. It was 6 clock hours and 12 manhours today.
If the black death had gotten throughout the system then the flush effort would have been several hours longer.
Black death is the term often used for the mixture of aluminum oxide, metal particles and burned oil that results when a compressor is run when it is not cooling well (low on freon) or making noise (broken piston, rod, bad bearing - something shedding metal and creating heat.
It can coat the entire system, sometimes to the extent that you cannot recover it - just replace it entirely.
We also donated a used driver's door window switch (installed) and a new serpentine belt (installed.)
So now she can roll down her window if the AC fails.
Zeb seeing her at church with the driver's window up, and no AC in June weather here in South Carolina is what started this ball rolling.
Update:
Zeb reported that on the drive back to her place the air temperature was holding 40 F with the fan in fast speed and 38 F with the cabin fan on the lowest setting. So it sounds as if the control valve is now working properly.