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    Maintenance of the lubrication system-Hannell tells you

    Release time:2019-12-20

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      1. The main failure of the lubrication system

      1.1 Oil pressure is too low or no pressure

      When the oil pressure is found to be too low, it should be stopped immediately for inspection. The possible reasons are:

      (1) Abrasion of main bearings, connecting rod bearings, camshaft bushings, etc., makes the mating clearance too large, resulting in increased oil leakage.

      (2) The oil pump is not working properly. Due to the worn end clearance and mesh clearance of the oil pump, the oil pressure is reduced.

      (3) The pressure limiting valve and the oil return valve are not closed tightly due to dirt or wear, or their spring force is weakened or broken.

      (4) The oil viscosity is too low or the oil temperature is too high, making the oil thin.

      (5) Insufficient amount of lubricating oil, and clogging of the filter (suction plate), oil filter screen, or air leakage in the pipeline.

      (6) The oil pressure gauge or oil pressure sensor fails.

      1.2 Oil pressure is too high

      Excessive oil pressure will damage the filter element. The main reasons are:

      (1) The oil viscosity is too large;

      (2) Incorrect adjustment of the pressure limiting valve;

      (3) The oil pressure gauge or sensor is not working properly;

      (4) The lubricating oil passage of the cylinder block is blocked;

      (5) The clearance between the main bearing and the connecting rod bearing is too small.

      1.3 The temperature indicated by the oil gauge is too high

      The main reasons are:

      (1) Diesel engine is overloaded for a long time;

      (2) Excessive high temperature exhaust gas penetrates into the crankcase, and the ventilator has poor ventilation;

      (3) The oil radiator does not work well, or the cooling system does not perform well.

      1.4 Excessive oil consumption

      When the diesel engine oil consumption exceeds 0.1 to 0.5 L / 100 km and the blue smoke is emitted from the exhaust pipe, it indicates that the engine oil is consumed too much and the organic oil enters the combustion chamber for combustion. The main reasons are:

      (1) Cylinder and piston, cylinder and piston ring clearance is too large;

      (2) The piston ring is damaged and worn, and the opening is not staggered or reversed;

      (3) The intake duct is severely worn;

      (4) Too much engine oil;

      (5) The oil circuit is not sealed and there is leakage;

      (6) The oil viscosity is too low.

      2.Technical maintenance of lubrication system

      (1) Use oil products correctly. Engine oil plays an important role in the lubrication system. It not only “lubricates” and reduces frictional resistance, but also has various functions such as reducing friction, sealing, cooling, purifying, and rust prevention. It affects whether the diesel lubrication system can work normally Very large and must be selected correctly. Domestic automotive diesel oil grades are commonly used: CA, CB, CC, CD, CE, CF, CG represent quality grades, where the first letter C represents diesel engine oil, and the second letter A, B, C, D, E, F and G indicate the quality grade of the lubricating oil. The higher the grade, the higher the oil quality. The oil viscosity has a total of 0W, 5W, 10W, 15W, 20W, 25W and other grades. Different letters indicate different viscosity levels. The more backward the letters, the higher the viscosity level. Tractor generally uses lubricating oil with relatively high viscosity, such as 20W, 25W viscosity grade. Tractor diesel engine oil is relatively backward, and CA manual lubricants are recommended in the instruction manual. When conditions permit, CC grade diesel engine oil is recommended. If single-grade oil is used, it is necessary to change the grade according to the temperature.

      (2) Regularly check and change the oil in time. Before starting the diesel engine, check whether the oil level of the oil pan is between the upper and lower engraved lines on the dipstick. After the diesel engine has been running for a certain period of time, due to the invasion of external impurities (dust and moisture), the metal wear debris generated by the wear of parts and the oxidation and combustion of lubricating oil generate carbon deposits, gums and acidic substances, which deteriorate the engine oil and lose its lubrication effect. Therefore, the oil must be changed regularly (approximately 100 h) as specified in the instruction manual. If there is an inspection instrument to test the performance of the lubricating oil, or if it has the ability to judge the quality of the engine oil, you can change the oil according to the quality. When cleaning the oil, pay attention to the cleaning of the lubricating oil circuit. How to clean the lubricating oil circuit: unscrew the drain plug, drain the oil from the oil pan, remove the oil filter, and clean it; install the filter with the filter element and the drain plug; add it from the filler A mixture of diesel and engine oil (5: 1 ratio), about 7 L for a four-cylinder engine and about 3.5 L for a two-cylinder engine; set the throttle to the stop position and press the pressure reducing handle; use a crank to turn the diesel engine to about 5 minutes, then release the mixed oil; remove the oil filter, remove the mixed oil, and replace with a new filter element; add new oil to the specified oil level.

      (3) Keep the lubrication system clean. Here are four reminders: First, the "centrifugal purification chamber" (ie, the inner cavity of the connecting rod journal) of the crankshaft must be cleaned to remove the sludge inside it; second, the logo cover on the pressure indicator must be cleaned frequently. If you see the red sign clearly, you can know the oil pressure situation in time; the third is the diesel engine with a centrifugal oil filter. Pay special attention to the working condition of the rotor to ensure that the rotor works normally. Fourth, when driving, the crankcase should be well ventilated to prevent the vents from being blocked, which will cause the crankcase pressure to rise and the engine oil to deteriorate.

      (4) Check the oil pressure frequently. The oil pressure plays a decisive role in the operation of the lubrication system. The oil pressure must not be too high or too low. If the oil pressure is too low, the oil will not be able to reach the surface of the parts that need to be lubricated. When the oil pressure is too high, the high pressure oil flow will damage the lubricating oil circuit, causing oil leakage and affecting lubrication. Therefore, pay attention to the change of oil pressure in the lubrication system.

      (5) Regularly clean, check and adjust the oil pump and maintain the filter. After working for 50 ~ 60 hours, the metal band gap filter should be brushed along the copper wire, and it should not be scrubbed with a metal brush or cotton yarn. If the copper wire gap is too large, it should be repaired or replaced. After cleaning and repair, the filter element should be checked for capacity; plug the filter port with a plug and infiltrate into clean diesel at 20 ℃, and measure the time when the diesel penetrates 30 mm from the upper edge of the filter element. The normal filter element time is 20 ~ 40 s, the longest must not exceed 120 s, otherwise it needs to be repaired again. When installing, the upper and lower gaskets on both ends of the filter element and the gaskets of the filter housing must be intact. Centrifugal filters are generally cleaned after 240 to 250 hours of operation.