Leaky Hot End

[printbus]

And while you have it apart, clean off the end mating surfaces of the barrel and the nozzle as meticulously as you can. I even de-burr the components by rotating them around on a piece of super fine hobby sandpaper. Those surfaces need to mate perfectly or you'll have another leak.

[spaceorange12]

I took everything apart and assembled it like you all specified. I also included some teflon on the heat barrel threads. After I mounted it on my extruder, I tried to manually extrude some filament (this happened at 180˚C). Apparently the pressure was too much for the nozzle, which popped off. And this isn't a problem where the threads stripped, the nozzle literally broke at the point where it meets the heat block and fell off. I must have weakened it somehow when pulling it apart and putting it together, but there were no visible signs of cracks, torsion, etc. Unbelievable.
Since I am done dealing with hotends, I'm doing some research to find a hotend that works out of the box. I really appreciate the advice everyone gave me, your instructions were fine but I must have messed up somewhere.