After the first operation of the air compressor, what parts need to be disassembled and inspected?

1. The lubricating oil in the air compressor body needs to be replaced
2. Check the surface friction of the piston rod of the air compressor for wear marks and scratches
3. Remove the connecting rod big end bush and crosshead pin of the air compressor and check the friction of their friction surfaces
4. Remove the air cutting at all levels of the air compressor and the front cover of the cylinder, check the friction of the cylinder surface and find out the cause