Mixtures of refrigerant usually have undesirable thermal properties compared to either one alone. It is like when tin and lead are mixed to make solder, the resulting mixture has a lower melting point than expected by looking at the melting point of either metal alone. Thus it is highly preferable t...

A vacuum pump is used only when the system pressure is already zero to take the air out of the lines and leave a vacuum to be filled with refrigerant. It is a different kind of machine which will recover the refrigerant and save it in a tank. By weighing that tank before and after you can tell how m...

I wouldn't trust a used TXV. A new one is only about $20 and good to go with R-134a.

There's only a couple oz of gas left in that tank. You will need to procure more R-12. Empty tanks should be pulled into a vacuum using a recovery machine, then punch a hole in the tank and recycle the metal. The refrigerant in the recovery cylinder can be used.

Don't turn it at all. Look on the top of the valve it often says R-134a. In any case, the difference is slight enough that new TXV's are set up to to work with either refrigerant. The screw changes the temperature-pressure response of the valve not a fixed opening. Adjustment requires operating the ...

Are you really seeing liquid in the sight glass, or just clear gas? You should see it fill up and clear with bubbles and liquid when you start and stop the compressor. Do you know of any history of a stop-leak compound being used in this system, or having a blown compressor and replacing it without ...

Forums work better if people don't start new threads about the same problem they're having. Bump up your original thread with any new findings.

You'll have to get a schematic and trace where the signal goes. In the older models anyway the control panel pulls a wire low to demand A/C. This ground signal passes through the pressure switch to the ECU / PCM. If the control panel is bad or the wire is shorted to ground, it will come on as soon a...

If it's a pressure controlled electric condenser fan you can easily see a 225 high side with a low charge. This is because the fan stays off until the trip pressure is reached, allowing the condenser to get very hot.

It's undercharged. Look for a sticker or look up in the service manual for the amount of refrigerant required. One can is not going to be enough.

Finding the pressure at zero usually means there's a serious leak.