The correct maintenance of diesel engines, especially preventive maintenance, it is the easiest and most economical maintenance, so it is the key to extending the service life and reducing the cost of use. First of all, it is necessary to do a good job of daily reporting during the use of the diesel engine, and make necessary adjustments and repairs in time according to the situation reflected. Based on this and referring to the content of this chapter, different maintenance schedules can be drawn up according to different users' special working conditions and experience.
The content of the daily report generally has the following aspects:
The date and start and end time of each shift; routinely record the readings of all meters; power usage; whether fuel, engine oil, or coolant leaks or over-consumption; exhaust smoke and abnormal sounds; before and after failure And handling opinions.
一. The main content of maintenance:
Users should perform regular maintenance according to the technical maintenance items listed in this section. The maintenance classification is as follows:
Routine maintenance (work per shift);
Level 1 technical maintenance(accumulative work 100h or every other month);
Level 2 technical maintenance (accumulative work 500h or every six months);
Level 3 technical maintenance (accumulative work 1000-1500h or every other year);
No matter what kind of maintenance is to be carried out, disassembly, inspection and installation should be carried out in a planned and step-by-step manner, and tools should be used reasonably, with appropriate force, and the surfaces of all parts after disassembly should be kept clean and coated with anti-rust oil or grease. Prevent rust; pay attention to the relative position of the detachable parts, the structural characteristics of the non-detachable parts, as well as the assembly gap and adjustment methods. At the same time, keep the diesel engine and accessories clean and complete.
1.Daily maintenance
Routine maintenance items and procedures can be carried out as follows:
| Serial number | Maintenance item | Proceed |
| 1 | Check the fuel level in the fuel tank | Observe the amount of fuel in the fuel tank and refill as needed |
| 2 | Check the oil level in the oil pan | The oil level should reach the engraved mark on the oil gauge, if it is insufficient, it should be added to the specified amount |
| 3 | Check the oil level of the fuel injection pump governor | The oil level should reach the engraved mark on the oil gauge, and add enough if insufficient |
| 4 | Check the three leaks (water, oil, gas) | Eliminate oil and water leakage on sealing surfaces such as oil and water pipeline joints; eliminate air leakage at intake and exhaust pipes, cylinder head gaskets and turbochargers |
| 5 | Check the installation of the accessories of the diesel engine | Including the stability of the installation of various accessories, the reliability of the anchor bolts and the connection with the working machinery |
| 6 | Check each instrument | Observe whether the reading is normal, otherwise repair or replace in time |
| 7 | Check the drive connecting plate of the fuelinjection pump | Whether the connecting screw is loose, otherwise the fuel injection advance angle should be re-calibrated and the connecting screw should be tightened |
| 8 | Clean the exterior of diesel engine and ancillary equipment | Wipe off the oil, water and dust on the surface of the fuselage, turbocharger, cylinder head cover, air filter, etc. with a dry cloth or a rag soaked with diesel; wipe or blow off the charging generator with compressed air to dissipate heat Dust on the surface of the device, fan, etc. |
Level 1 technical maintenance
In addition to the routine maintenance items, the additional work is shown in the following table:
| Serial number | Maintenance item | Proceed |
| 1 | Check battery voltage and electrolyte specific gravity | Use a hydrometer to measure the specific gravity of the electrolyte. This value should be 1.28-1.30 (when the ambient temperature is 20J), and generally should not be lower than 1.27. At the same time, the liquid level should be 10-15mm higher than the electrode plate, and distilled water should be added when insufficient |
| 2 | Check the tension of the triangular rubber belt | Check and adjust the belt tension according to the belt tension adjustment method introduced |
| 3 | Clean the oil suction coarse filter of the oil pump | Disassemble the large window cover of the body, open the spring lock plate of the coarse filter, remove the filter and clean it in diesel, and then blow it off. |
| 4 | Clean the air filter | Inertial oil-bath air cleaners should clean the steel wool core and replace the oil; basin (cyclone) air filters should remove dust on the dust tray and maintain the paper filter core |
| 5 | Clean the filter element in the vent pipe | Take out the oil core from the refueling pipe on the door cover of the machine body, clean it in diesel or gasoline, and install it after dipping in oil |
| 6 | Clean the fuel filter | Every 200h or so, remove the filter element and the shell, clean or replace the element in diesel or kerosene, while removing moisture and sediment |
| 7 | Clean the oil filter | Generally every 200h or so: ①Clean the wire-wound coarse filter element ②For the wiper filter, turn the handle to remove the oil on the surface of the filter element, or place it in diesel for scrubbing ③Put the centrifugal filter rotor in diesel or kerosene for cleaning |
| 8 | Clean the oil filter and oil inlet pipe of the turbocharger | Clean the filter element and tube in diesel or kerosene, and then blow dry to prevent contamination by dust and debris |
| 9 | Change the oil in the oil pan | Change the oil every 200h-300h according to the use condition of the oil (the degree of reduction in the viscosity of the oil dirt) |
| 10 | Add lubricating oil or grease | Fill all grease nipples and mechanical tachometer joints with grease or oil that meets the requirements |
| 11 | Cleaning the cooling water radiator | Pour clean water into the radiator and remove the sediment until it is clean |
Level 2 technical maintenance
In addition to the first-level maintenance items, additional work items need to be added as follows:
| Serial number | Maintenance item | Proceed |
| 1 | Check the injector | Check the fuel injection pressure, observe the spray situation, and perform necessary cleaning and adjustment |
| 2 | Check the fuel injection pump | Readjust if necessary |
| 3 | Check valve clearance, fuel injection advance angle | Adjust if necessary |
| 4 | Check the intake and exhaust valves and sealing conditions | Remove the cylinder head, observe the sealing and wear of the mating cone surface, and grind and repair if necessary |
| 5 | Check the water pump leakage | If water drips from the overflow, the sealing ring should be replaced |
| 6 | Check the sealing water condition of the cylinder liner sealing ring | Remove the cover plate of the large window of the machine body, and check from the bottom of the cylinder liner for water leakage, otherwise the cylinder liner should be removed and replaced with a new rubber sealing ring |
| 7 | Check the fuel injection plug on the cover of the transmission mechanism | Remove the front cover and check if the nozzle hole of the fuel injection plug is unblocked. If it is blocked, clean it |
| 8 | Check cooling water radiator and oil radiator, oil cooler | If there is water or oil leakage, necessary repairs should be made |
| 9 | Check the tightening of main parts | Check the connecting rod, crankshaft nut, cylinder head nut, etc., if necessary, remove the check and re-tighten to the specified torque |
| 10 | Check electrical equipment | Whether the wire connectors are connected securely, and should be replaced if they are damaged |
| 11 | Clean the oil and fuel system pipelines | Including cleaning the oil pan, oil pipeline, oil cooler, fuel tank and its pipeline, removing dirt and blowing it clean |
| 12 | Clean the cooling system water pipe | You can fill the diesel engine cooling system with a solution of 150g caustic soda (NaOH) per liter of water and stay for 8-12 hours, then start the diesel engine, make the outlet water temperature above 75℃c, drain the cleaning fluid, and then clean the cooling system with clean water |
| 13 | Clean the gas and oil passages of the turbocharger | Including cleaning the wind guide wheel, compressor impeller, the inner surface of the compressor casing, the oil and carbon deposits of the turbine and turbine casing |
Level 3 technical maintenance
In addition to the secondary technical maintenance items, additional work items are required as follows:
| Serial number | Maintenance item | Proceed |
| 1 | Check the cylinder head assembly | Check the wear of the valve, valve seat, valve guide, valve spring, push rod and rocker arm mating surface, and if necessary, refurbish or replace |
| 2 | Check the piston connecting rod assembly | Check the wear of piston ring, cylinder liner, connecting rod small end bushing and connecting rod bearing bush, and replace if necessary |
| 3 | Check crankshaft assembly | Check the wear of the thrust bearing, the thrust plate, whether the inner and outer rings of the rolling main bearing have circumferential floating phenomenon, replace if necessary |
| 4 | Check the transmission mechanism and valve phase | Check the gas distribution phase, observe the wear of the meshing surface of the transmission gear, and measure the meshing gap, repair or replace if necessary |
| 5 | Check the injector | Check the spray condition of the fuel injector and grind or replace the fuel injection assembly if necessary |
| 6 | Check the fuel injection pump | Check the tightness of the plunger and coupling and the wear of the flying iron pin, and replace if necessary |
| 7 | Check the turbocharger | Check the wear of the impeller and casing and clearance, floating bearing, turbine rotor shaft, gas seal, oil seal and other parts, repair or replace if necessary |
| 8 | Check oil pump, fresh water pump | Disassemble, inspect, measure and adjust vulnerable parts |
| 9 | Check the cylinder head and the gaskets of the intake and exhaust pipes | Damaged or lost sealing should be replaced |
| 10 | Check the charging generator and starter motor | Clean the parts, bearings, add new grease after drying, check the gear wear of the starter motor and whether the transmission is flexible |
