Answer Hi Ray. Basically the manufacturer pre determined compressor oil fill level. They (compressors) are all fitted per sealed system freon need size combined with the length and the diameter of the tube size. Under fill and over fill is extremely detrimental. Send us your model # as then we will be able to see what the manufacturer recommends for your particular model #. Thank You. Read More... Answered by AppliancePartsPros.com | Friday, April 20, 2012