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A/C Oil Help

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Old Apr 8, 2008 | 10:27 PM
  #1  
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78anniversary
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Racer
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From: Rockford MI
Default A/C Oil Help

Hello All, Getting ready to assemble my A/C system on my 78. New Comp, Hose, Accumulator. Condenser and Evaporator have been flushed. What kind of oil should I use? PAG or Esther? Not sure of the difference. I do plan on using R134a. Thanks
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Old Apr 8, 2008 | 10:59 PM
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maddmickey
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You should alwas use PAG oil in 134 systems. I'm not sure what weight of oil for your aplication.
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Old Apr 8, 2008 | 11:25 PM
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mdj21
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acutally, i think the ester oil is a better choice.

the original mineral oil used is compatable with R12 but not with R134a. PAG oil is compatable with R134a but not with R12.

Ester oil is compatable with both R12 and R134a. if you should change your mind after the conversion to R134a and decide you want to go back to R12 you will not have to flush the oil out of the system. simply evacuate and refill with R12.

you can't go wrong with either PAG or ester oil, but personally i'm going to use the ester oil for my conversion.

hope this helps,

Mike.
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Old Apr 9, 2008 | 02:41 AM
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noonie
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Pag150 if the system has been flushed, 8 oz total.
Use what the manufacturer has filled or recommebded.
A lot of compressors come prefilled. Double check that.
Newer synthetic pag oils are backwards compatable with trace mineral amounts.
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Old Apr 9, 2008 | 08:09 AM
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Do you know what would happen if there was trace amounts of mineral left and mixed with a non compatible oil?
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Old Apr 9, 2008 | 11:20 AM
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probably nothing. the incompatable oil would not mix with the refrigerant so it would not do much of anything except take up space that would be better filled with refrigerant.

if you flush your system like you should do for a proper conversion, there will not be any residual mineral oil anyway.
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