6610 S/N 500923-, 6710 S/N 500923-, 6810 S/N 500923-, 6910 S/N 500923-,(7200,7300,7400,7500,7700,7800, All S/N -earlier); The following steps must be performed prior to compressor installation for warranty to be considered on all A/C compressors. Failure to do so will void all warranty. 1.The system (condenser, evaporator, lines, etc.) needs to be flushed with an approved liquid? 2.A new receiver-drier or accumulator needs to be put on.3.The expansion valves or office tubes needs to be inspected - cleaned - replaced. 4.Inspect the lines.5.The condenser and evaporator needs to be checked/cleaned of debris. 6.Properly vacuum system down. 7. Use the recommended type and amount of oil needed. 8.Install the proper Freon level. 9. Hand turn the compressor after filing with Freon. 10.Check the voltage to the compressor. 11.Check the system for leaks. 12.The proper documentation/shop work order of the above steps needs to accompany the compressor for warranty.