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Old 09-12-2018, 09:08 AM
97 SL320 97 SL320 is offline
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Originally Posted by 400Eric View Post
My main concern is getting every trace of the old oil out, which, as I understand it, is downright toxic to the new R134a and the oil we are supposed to use with it.
Not a problem having some mineral oil ( used with 12 ) in a PAG system.

Mineral oil dissolves in 12 allowing it to circulate through the system. Mineral oil does not dissolve in 134 so it pools in various areas, this causes a loss of compressor lubrication. Most modern AC compressors do not have a sump and act as a 2 stroke engine so oil movement is vital.
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