Hi guys. I'll go ahead and explain my situation. My 04 ford mustang ft is overheating. There are no leaks other than when it overheats the cap starts to smoke and spew antifreeze. See the thing that gets me is that it's not leaking antifreeze until after it starts overheating or get to almost the red line. I don't let it get to the line though. I thought replacing the cap wouldn't really do anything because it's already over heating by the time it gets to the point where it's leaking antifreeze from the cap. Another side note I can smell it in the car not sure it that means anything I think it was coming from the vents. It all started happening after I had a friend try and recharge my ac. He did it on his car and it worked fine so I thought he could try it on mine. After he finished putting the r134 in we had the AC on blast and then all of a sudden the AC got super warm and then the smoke started coming from the expansion cap and the car started to over heat. Thanks for checking it out guys.