Coolant change question (overflowing out of cap after driving)

[SpectorV]

I, a week ago, changed my coolant in my car and even drained the blook. It had ford gold and I used the prestone that can mix with any type (so said on the bottle) in 50/50 mix (after I flushed a bit more with tap water). I drained the system and filled it good right up to the top of the cap in the overflow tank.

I checked it the day after I changed it (and first noticed this after the car was cold and had sat overnight) and I added some to fill it back up (to the top of the cap) as it was right at or slightly lower than the Add Coolant line on the overflow tank.

Tonight right after returning home from a good 30 minute drive I noticed some coolant had eased out of the back of the cap and when I removed the cap to check a good bit of fluid came running out and was quite hot (100 percent normal I assume).

Is it due to I overfilled the system a bit by filling it all the way up to the cap and when it gets hot it needs the extra room in the overflow tank? Should the fluid only be filled to the Add Coolant line thats on the side of the overflow tank? Just wanting to make sure I dont need to check anything else and had simply just overfilled the coolant, I took my time and got all of the air out of the system (I want to take the top peice near the sc pulley back off the double check for any air... but my socket isnt doing it and im afraid of breaking or rounding it out so ive not gotten it off to check again yet. The car gets warm right to the middle of the gauge and doesnt budge and it seems to be working perfectly normal temp wise...

any input or things to check please let me know

[rocknbronco]

yeah it sounds like you simply over filled it