Tests have been conducted to evaluate materials suitable for headers of CAB brazed aluminum radiators, particularly as concerns pressure cycle endurance. These tests were done on different alloy compositions, for both standard and proprietary versions from series 6000 and 3000, with or without post-braze heat treatment. The results from those tests have helped to evaluate the influence of various material characteristics over the pressure cycling resistance. In particular, they have shown that post-braze yield strength was not the only parameter to consider. It appeared also that none of the materials tested could give good results for all designs and test conditions, but, at least, this study has helped to state more precisely what the contents of a specification for an ideal material should be.