Flushing of the Tractor Engine Lubrication System and Its Effect on the Technical Condition of the Machine and the Service Life of Freshly Refueled Engine Oil

The results of studies to assess the influence of the operation of flushing the lubrication system of tractor engines on some technical characteristics of the machine and the service life of freshly filled oil are presented in the work. It has been established that during the operating process, contaminants accumulate in the oil, which gradually, despite the operation of oil purification devices, accumulate in the oil channels and on the bottom of the oil pan. The dependence of the change in the content of mechanical impurities, insoluble sediment and color over an operating period of more than 200 hours is presented. Contamination reduces the effectiveness of additives, increases the acid number of the oil, which intensifies wear of parts, increases operating and repair costs. It has been shown that over a period of 240 hours of oil running in a tractor engine, the alkaline number decreases from 8.5 mg KOH/g to 4.0 mg KOH/g, and the acid number increases from 2.0 mg KOH/g to 2.5 mg KOH /g for M10DM oil when the engine is running even without high loads. The chromatogram of the color change of an oil stain on filter paper is presented as an express method that confirms the contamination of the oil and, in some cases, is a simplified method for analyzing the quality of the oil and showing the need to replace it and flush the lubrication system. In a comparative mode, it is shown that flushing the lubrication system after draining the used oil significantly affects the dynamics of contamination of freshly filled oil. The dependences of changes in the content of contaminants and oil color on the operating time in the engine after flushing it with Lukoil flushing oil are presented. The dependence of changes in alkaline and acid numbers is shown. The tests were carried out on two MTZ-82 tractors of almost identical technical condition. In general, it has been determined that carrying out the operation of flushing the lubrication system when replacing used oil with fresh oil can increase compression in the cylinders by 10–15 percent, reduce fuel consumption by 5…8%, and increase the service life of the oil before replacement by 15…20 percent.