Where did my antifreeze in my radiator go? 92 Chevy P\U V-8?

When I put antifreeze in my truck and drive a few days , the overflow tank will be emty and the radiator will be half emty . I can't find out where it is going . I have checked the hoses,radiator and heater they'er not leaking . I have checked the motor oil no water and there is no steam coming from the exhaust . I'm lost I can't find out where its going . I need some help,could someone give me some answers, as to where the antifreeze-water is going ? Thanks Ric