Technical Help Needed

First off I have a 2004 GT, manual with 105k. I replaced all 4 rotors all pads, all 4 calipers, and both front brake lines to the calipers. Bled all calipers several times. RR, LR,RF,LF.
As well as just the rears twice and just the fronts twice. I have clear fluid coming out and no air bubbles.

Here's the problem. The LF-driver side caliper keeps sticking and getting hot. (everything lubed, slides good, etc)
I did not bleed the master cylinder. That's next.
get to the point right? ... under the master cylinder is a proportioning valve/combination valve/distribution block/ I don't know what to call it. Can't seem to find one online to purchase as if they don't exist. Can someone tell me the true name of this part and where I can purchase one. I suspect something is sticking here and pushing most of the brake fluid to the front brakes and not allowing fluid to flow back. Suggetions, thoughts?? I just installed 373s and want to burn up some tires!

Here is a pic of the brake fluid block I was talking about. (If I can upload correctly)

Thanks wmburns, I ended up bleeding the master cylinder which fixed the fading brake pedal. Jack the car up and still have pressure on LF keeping the wheel from spinning. I'm also suspecting a bad master cylinder. I figure I could take the front line off the master and see if it frees up that wheel. And if so that would verify a bad master cylinder. Still don't know about that proportioning valve, still can't find one online?? Dealer only part maybe.