NOTA TÉCNICA: CUSTOS DE MANUTENÇÃO PREVENTIVA PARA TRATORES EM FUNÇÃO DO TIPO DE TRAÇÃO E CATEGORIA DO SISTEMA HIDRÁULICO - DOI: 10.13083/1414-3984/reveng.v23n3p270-277

Stimulated by accessible agricultural credit policies and seeking better working conditions, Brazilian family farming has undergone constant transformations regarding agricultural machinery. In this scenario, the agricultural tractor is increasingly present, therefore understanding its maintenance costs is strategic to economic sustainability of family production units. Due to this reality, the objective of this paper is to compare the maintenance costs with regards to filter, lubricants and tires changing of agricultural tractors with engine power up to 72.9 kW, subdivided into type of traction and hydraulic system category. In order to perform this study technical data was collected along with lubricant prices and periodic replacement materials. Quantitative and qualitative variables were: technical specifications – brand, model, maximum engine power, tire designation, duration and changed quantity of filters, lubricants and tires. From the 94 analyzed models, 25 had traction on both drive wheels and 69 had auxiliary front wheel drive traction (TDA). The study concluded that lower average maintenance costs are obtained for 4x2 tractors with category I hydraulic system, while higher average maintenance costs are obtained in 4x2 TDA tractors with category II hydraulic system. The coefficients of variation found were high among the studied models with minimum and maximum costs of R$ 0.82 and R$ 5.73 (R$ h-1), respectively.