Do not heat the piston with open flame

Because the piston and piston pin are interference fit, when installing the piston pin, the piston should be heated and expanded first. At this time, some maintenance personnel will put the piston on the open flame and directly heat it, which is wrong. Because the thickness of each part of the piston is uneven, the degree of thermal expansion and cold contraction will be different. The open flame heating will cause uneven heating of the piston, which is easy to cause deformation; Carbon dust will also be attached to the piston surface, reducing the service life of the piston. If the piston cools naturally after reaching a certain temperature, its metallographic structure will be damaged and its wear resistance will be greatly reduced, and its service life will also be significantly shortened. When installing the piston pin, the piston can be evenly heated in hot oil to make it expand slowly. It is not allowed to heat it directly with open flame.