Mark, I'd always heard that water moisture mixed with the R12 creates an acid which can destroy or corrode A/C components and washers/o-rings; hence the reason for having a dryer in the system and evacuating the system in certain circumstances like this one.

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Chris
1985 300SD - 'Grace' (198K mi.)
2018 Honda Civic Sport
2018 Honda CRV LX
2010 Honda Fit Sport (RIP)
2013 Honda Accord Sport (Sold)
1996 Lexus LS400 (Retired)
1995 Ford Contour SE (Retired)
1976 Porsche 914 (Sold)
1972 Datsun 240Z (RIP)