1.Smear the butter randomly
The main function of butter is to lubricate and seal.So, some repairmen in the process of maintenance, on the cylinder liner butter, thinking that can increase the sealing performance of diesel engines.In fact, it's wrong. if butter is applied to the cylinder gasket, a portion of the butter must flow into the cylinder when the cylinder bolts are tightened.The remaining butter on the outside will cause a certain gap between the cylinder pad, cylinder cover and body plane after being affected by the high temperature, which will reduce the original sealing of the cylinder pad.
2. The cylinder liner and piston products shall be installed without combination
When a lot of repairmen are repairing, think new product should be standard.Therefore, in the face of new cylinder sleeve and piston products are often no specific size.This will cause a lot of times the cylinder sleeve and piston products do not match, when the largest size of the cylinder with the smallest size of the piston, they will make the gap between too large, weak compression.
3. Heat the piston with open flame
The piston should be allowed to expand with heat before installing the piston pin.Many maintenance workers simply put it on an open flame for convenience.However, because the thickness of each part of the piston is not uniform, heating it over an open flame will result in uneven heating, which will lead to deformation.So, the correct way to heat it is to put the piston in the hot oil.
4. Abrasive cloth to polish the bearing shell
Scraping tile is a relatively high technical work in the maintenance of engineering machinery. Because of their own technology is not up to standard, a lot of repairmen will directly use the abrasive cloth to polish the tile during the process.However, during the process of grinding with abrasive cloth, the sand on the abrasive cloth can be easily embedded into the alloy to accelerate the wear of the diesel engine shaft neck.
5. The bolt is tightened violently
In the process of engineering machinery maintenance, it is not actually the tighter bolt is more secure.This is mainly because many parts are required for the torque of bolts.However, many repairmen do not think so, they will try to screw it to the tightest possible, which is easy to cause the bolt to break, or the thread slip.
6. The water tank boil and add cold water
When the engine is overloaded and the heat dissipation is not good, the water tank will boil.The first reaction of many repairmen is to add water, but if cold water is added at this time, the cylinder head and cylinder body will burst, so the engine should be stopped at this time, and water should be added after it cools naturally.
7. Measurement between cylinders is inaccurate
To measure the cylinder gap, measure in the direction of the piston skirt perpendicular to the piston pin hole.However, many repairmen make measurements in other directions because they do not pay attention.However, because its skirt section is elliptic, so, air cylinder gap is not equal.