After riveting, riveting area has void(Riveting not tight)

1. Need to check the barometer, have to be sure the number is in 6-8.
2. Hydraulic riveting need to change the stroke according to the Plate, if has void after riveting, it may the stroke caused, please adjustment to the correct.
3. Please check the inside parts of riveting gun, to make sure no damage for the inside parts.