How much PAG oil to add?

TheYonderGod said:

2000 TJ, total amount of oil required is 6 ounces.

The a/c system has been empty since I bought it 2 years ago, and I don't know how long before that but I'm guessing at least 10 years. I found the major leak in the high side valve, so I replaced that, and all of the o-rings that I can easily get to. Pulled a vacuum and it held 12+ hours overnight. Now I'm also replacing the dryer/accumulator before I charge it.

My problem is I don't know how much oil leaked out from the initial valve blow out and over the years. A very tiny amount leaked out when I was removing and reinstalling the lines, and I just took out the accumulator, I was planning on measuring how much oil was in it, but it only had a very tiny amount in it. So now I don't know if all the oil is in the compressor or if most of it leaked out.

Wwyd? Just add like 3 ounces and send it? Or should I remove the compressor and drain it and add ~5 ounces?

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Since the total capacity is 6 ounces and you found very little oil in the accumulator, you might be safe adding around 4 ounces to start. This way, you can ensure there’s enough oil for lubrication without overfilling.

If you're unsure how much oil is left in the compressor, it might be a good idea to remove it and drain any old oil. This way, you can more accurately measure how much oil is in the compressor and adjust your total accordingly based on its capacity.

Once you add the oil and charge the system, monitor it closely. If you hear any unusual noises or the system doesn’t function well, it may indicate oil starvation.

If possible, after running the A/C for a bit, you can check the oil level again (if accessible) to ensure you've got the right amount circulating.

By erring on the side of caution and gradually adding oil, you can avoid potential damage to the compressor.

I did the A/C on our van recently and was in a similar situation. I played it safe and added a little less than I anticipated and let it run for a while. Everything turned out great and the A/C works again!

Good luck with your A/C fix!