The performance of miniature instrument bearings in aircraft and marine guidance system is adversely affected by the presence of trace contaminants on the contacting surfaces. Effective cleaning of such bearings prior to assembly in these critical system is, therefore, of utmost importance. The authors' previous study critically examined the specific effects of the various current Navy solvent-cleaning procedures on specially cleaned bearing steel reference surfaces. In the present study, reference surfaces of 440C bearing steels were coated with very thin films of either a formulated synthetic hydrocarbon or a formulated polyol ester instrument lubricant and characterized by wettability, Auger electron and X-ray photoelectron spectroscopies. These coated surfaces were subjected to standard sequential cleaning procedures as well as to individual solvents at two Navy facilities, and then reanalyzed by the same methods, including Fourier transform infrared spectroscopy. Results are discussed in terms of cleaning efficiency, recontamination and types of random contamination.Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in San Francisco, California, August 18–21, 1980.