As mentioned in a couple of my earlier posts, I pulled down a vacuum for about 40 minutes which should be enough in my case as I did not open my system up.

Again, on some cars, ES-12a worked pretty well while on others, not so much. A/C performance on cars which produced mediocre results with ES-12a improved vastly with R12.

I use it now mostly for testing purposes as some leaks appear under pressure. You may get good luck with it in NJ as it doesn't get as hot as it does here in TX.

Good luck!

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With best regards

Al