Anyone else have this problem or know how to fix it?

I will fill up my rad, after the motor heats up excess fluid will go into the resevoir.. but it will NOT go back in. and after it cools and i check it.. i can't see any fluid in the rad... it's pissing me off...

 

Have you bled all the air in the system?

 

oh sorry... forgot to add.. we did bleed the air from the system. I had to put in a used rad because a couple weeks ago i was driving and a truck spun up a rock and blew a hole in my last one.

 

your radiator cap might not be sealing against your radiator....try a new/different cap...