Dodge Repair: Replacing new compressor in A/C system: how much oil to use?


Question
I am wondering if you can tell me what is the quantity of oil which I need when replacing the AC compressor?  Many thanks.  Appreciate it.  Bart

Answer
Hi Bart,
That compressor uses ND8 type PAG oil. When you simply replace the compressor the manual says to drain the oil from the old compressor into a container which is calibrated to tell you how much has drained out. (It is likely to be a very small amount, I think possibly less than an ounce, but I can't be certain). Then discard that oil. Then drain the oil from the new compressor into a clean container. Return to the compressor the amount of new compressor oil equal to the amount that was drained from the old compressor.
The total system oil amount is 6 oz. of which 2 is in the accumulator, 1 is in the condenser, 2 is in the evaporator, and the balance is presumably in the compressor and the rest of the system. No specific amount is listed for the compressor, and that is why you do what I listed above when you simply replace the compressor.
I hope this makes sense to you. The info is from the '04 Ram manual.
It took me nearly an hour to find and understand this information, so if you would rate and nominate me for "volunteer of the month" I would be most appreciative.
Roland