This article presents optimization studies of the controlled atmosphere brazing process used for aluminum charge air coolers. The aim of the research was to reduce the amount of flux residues while maintaining the required brazing degree, including the presence and quality of brazed joints. The study focused on two key process parameters: maximum brazing temperature and flux grammage. Their influence on the process outcome was evaluated using a full factorial experiment design. The results showed that increasing the maximum brazing temperature to 606 °C significantly improves the flowability of both the flux and the filler metal, enabling proper joint formation even at reduced flux grammage. Conversely, increasing the flux grammage above 3 g/m2 does not significantly affect the brazing degree, while leading to a noticeable increase in amount of flux residues. Based on the findings, the optimal process parameters were defined as flux grammage of 3 g/m2 and maximum brazing temperature of 606 °C. These settings allow for an up to 35% reduction in amount of flux residues and a 24% improvement in brazing degree. The results confirm the potential of technological improvement of the process through parameter control.