I. Monthly Maintenance
Besides the daily and weekly maintenance, the monthly maintenance should be finished by the professional maintenance personnel each month.
1.Clean the filter element of oil filter and fuel filter.
2.Check the pressure and wear of tyre. The pressure should be 0.27～0.39MPa(2.8～3.0kgf／cm2). If it is on the soft ground, we can adopt the lower limit.
3.Check whether the weld joint of the frame and working device which undertake more force cracks or not.
II. Quarterly Maintenance
Besides the daily，weekly and monthly maintenance, the quarter maintenance should be finished by the professional maintenance personnel each quarter.
1.Clean the cooling system of the engine.
2.Inject the grease to engine and electric starters and check the electrical system and binding post. If there is burn mark, we should change a new one.
3.Check and adjust the space of engine valve.
4.Check and adjust the time of the valve and advanced angle of the fuel injection.
5.Check, clean and adjust the pressure of the nozzle, oil beam and angle.
6.Inject the grease to the slip joint of the propeller shaft.
7.Change the oil of engine and fuel injection bump.
8.Check whether there is air leakage in air compressor, air cylinder, brake valve and pipeline.
9.Check whether there is the phenomenon of sedimentation in the turning cylinder and movable arm cylinder of the hydraulic system. If necessary, we should repair the oil cylinder, piston and distribution valve or change the sealing element.