Prevent damage to the O-ring in your AC service couplings at the same time increasing the ability and less likelihood to have a vacuum leak to suck in air by adding NYLOG around your service fittings
https://www.trutechtools.com/RT201B?gclid=CjwKCAjwx6WDBhBQEiwA_dP8rbpcNm5W4HJ0CXY5O70A6VDm0cYcTnE0jeDAWMnL_uCun2oDfB0fWhoCDW8QAvD_BwE
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