The article analyzes the maintenance of existing agricultural machines in a working condition, which should be followed by the development of a maintenance system taking into account the conditions of agricultural sector reform. Operational, technological, and functional indicators were determined for direct combining of wheat. Under these operating conditions, the productivity for 1 hour of the main time was 17.6 tons, which is slightly less than the technical conditions - at least 18 tons. This is due to the low yield of the harvested crop. The self-propelled combine harvester KZS-9M steadily performed the technological process, as evidenced by the value of this coefficient equal to 1, which also corresponds to the value according to the technical specifications - not less than 0.98. All indicators of the quality of the technological process: grain losses behind the combine thresher and behind the reaper, the quality of grain from the combine hopper (crushing and the content of trash impurities) are within the permissible values according to the technical specifications. For example: grain losses behind the combine thresher were 1.06% (according to the technical specifications, no more than 1.5%) and behind the reaper 0.24% (according to the technical specifications, no more than 0.5%). During the observation period, five failures were detected on these combines, all of which were of the second complexity group. The average number of failures of complexity group II was 1.7. The operating time between failures of complexity group II was 307.6 hours (5006.7 tons), which is higher than the value required by the technical specifications of at least 100 hours. For the four seasons of observation of the combines, the average operating time was 1055 hours (11387 tons). At the same time, the time between failures of complexity group II was 105.5 hours over the four years of observation (according to the technical conditions, at least 100 hours). This indicates sufficient technical reliability of the combines. No parts (assemblies) that have reached the limit of wear (resource) over the four years of observations of the KZS-9M self-propelled combine harvesters were found.