For the past few days my car has been over heating. when i check the radiator and the reservoir... both are empty... so i added fluid and checked for a leak... to my surprise... NONE!!!! no leaks in the hoses or clamps... my mechanic said it could be a leak in the a/c heater where it gets hot water to heat the a/c... is this possible? now he bypassed the hose for the heater ( no heater now) and im gonna check if my fluid levels still diminishes....what else can be the problem? tnx for the help....