I am changing all A/C components on my 89 Mustang except condenser and evaporator and I want to change from R-12 to 134A . The retrofit kit comes with ester oil but I here most people are using pag oil when changing over. Anyone have any suggestions on which oil to use?
You must use ester oil due to the fact that mineral oil will not mix with 134-A. Flushing the remaining components is also highly recommended, even so their is no way to be sure you have gotten all the mineral oil out! When mineral oil, P.A.G. oil and R-134-A are mixed, nasty black sticky **** is the result. On a Ford system you must also replace the high pressure hose from the condenser to the evaporator, as it contains the orifice. Check out www.fjcinc.com we use their products exclusively and have never had any problems.
Pag oil is used mostly in Fords with R134. There are several different number Pag oils. Find out what number they are using and how their system performs. They are most likely using Pag 46. Trust me on this.
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