No cool air from air conditioner (Leak from evaporator) Some customers may complain about no cool air from the vents when the air conditioner (A/C) is ON. This concern may be caused by A/C refrigerant leaking from the evaporator (A) at the joint between the tubes (B) and the header (C) due to improper brazing (D). To correct the problems, the coinfiguration of the header has been changed to improve the brazing performance in this area.