POE (ester) Oil is reported to be compatible with both Mineral Oil and R-12. You could try contacting Sanden with the model and serial numbers of your compressor, asking whether they can tell you what the factory-fill oil was 12 years ago. Then add one ounce of the same oil into the new R/D. If Sand...

Make sure that the adapters are securely attached to the test ports on the car, that the thumb-wheels are open (turned fully clockwise ), and that the HP hand-wheel is closed on your Manifold Gauge Set while charging. Check to ensure that your small cans don't contain any sealer. Sealer is bad news ...

In addition, ensure that you add only Mineral Oil, which is compatible with R-12, and not PAG Oil, which is compatible with R-134a. Do you recall what you put in it when you last had the system apart? POE Oil perhaps? In that case, add POE Oil and not Mineral Oil. Consider a "couple extra ounce...

This should have been a simple task, but I managed to screw it up. I'm embarrassed to admit that I also had the hoses attached backward (low port to high gauge, high port to low gauge), so I was in fact charging the low side after all. I was in a hurry, and I doing something I'm not familiar enough...

What did you use to charge it, small cans or 30-pound cylinder? I hope you charged it with the compressor turned off. Otherwise, you risked the can or cylinder exploding with the HP valve open. Obvious severe danger to yourself as well. You mentioned that the system is now working okay. What are the...

If presented with a choice, I would go with a piston compressor over a scroll. The only parts I've had trouble with in the past are aftermarket TXV's. And I agree...start with a scrupulously clean and dry system, add PAG oil and pure refrigerant according to the manufacturer's specs, and your compre...

I heard today that Washington and Oregon are supposed to be in the 90's next week—unusual for the mild Pacific Northwest but de rigueur for those of us in typically warmer climates. Regardless, it should be excellent A/C testing weather in your area. The accumulator, receiver/dryer, or desiccant bag...

I still suspect that the system is low on refrigerant due to a slow leak someplace, although it hasn't leaked out enough yet to prevent the compressor from running.

By "blowing warm air," do you mean heated air or ambient air?

Let's see the pressures with the engine at about 1,800 RPM, compressor engaged, radiator fan(s) roaring, blower on high, and doors/windows open for a maximum heat-load test. If all goes as expected, the HP will rise somewhat and the LP will stay about the same. As for the static pressures, I'd give ...

I selected a car that has its original ac system intact with no signs of dies or stop leaks. I pulled it (the compressor) and drained it to see if any crap came out of it. Just clean clear pag oil. No other garbage. Clean oil draining from the junkyard compressor is a good sign, but we don't know a...