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Old 09-12-2018, 01:52 AM
ah-kay ah-kay is offline
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Join Date: Mar 2009
Location: San Diego
Posts: 2,928
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.
I think you are mis-guided. You don't need to get all the old oil out. It is impossible anyway. I never flush the system. You can mix mineral oil ( in R12 system ) with ester oil or pag oil. I always do the minimum and it always come out good and cold. I have done 6 conversions. The only one which is marginal is the car with the R4 compressor. The oil is only lubricant for the compressor. It does not care whether it is old or new oil in my opinion. It is not toxic to the R134a. I think the R134a is more toxic chemically.
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details.

2 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.
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