This is not a defect. The core sidepiece of a radiator has a thermal expansion joint, aka stress cut, to allow thermal relief in the radiator as the radiator expands due to temperature variations during operation. The thermal expansion joint is created by first brazing the sidepiece to the radiator core and then cutting through the sidepiece. This
Body
This is not a defect. The core sidepiece of a radiator has a thermal expansion joint, aka stress cut, to allow thermal relief in the radiator as the radiator expands due to temperature variations during operation. The thermal expansion joint is created by first brazing the sidepiece to the radiator core and then cutting through the sidepiece. This expansion joint aids in the prevention tube to header cracks.