15 minutes may not be enough to boil off all the moisture. Also, you're not going to charge it with 134a after all that work, are you? Besides the better performance, R12 will develop lower system pressures, which will let your compressor run quieter and longer.

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.