Why does left front brake overheat?

Replacement of the flexible line fixed the problem. The old line was indeed blocked in the area where the supporting clamp wraps around the flex line. (I cut the line several places to narrow down the location.) The blockage acts as a "check valve" letting fluid through under pressure from the master cylinder, but letting it flow back only very slowly once the brake pedal is released, thus keeping the brake engaged longer. While trying to recreate the problem prior to changing the hose, I found if I pressed the brakes hard while at a stop on level ground, there was a delay before the car would move forward at idle after releasing the brakes. Also had a bit of an adventure with the new part purchased at O'Reilly Auto Parts, "BrakeBest" brand, PN BH620474, $23.99 +tax. Initially, the new hose leaked at the caliper/hose joint. Inspection of the new copper washers provided with hose showed that the outer washer had embedded onto the hose mating surface thoroughly, as evidenced by clear concentric ring markings on the surface of the washer. The inner washer (between hose and caliper) showed little evidence of being deformed, despite having the identical clamping pressure applied to it. This suggests the inner washer was too hard, not properly annealed. A comparison of the new washers to the old (still embedded on the old hose) showed that the new ones are larger in OD (0.637" vs. 0.590") with about 1/3 more surface area, making them that much more difficult to "crush." I took one of the old washers and used it (smoother side toward the new line surface) and the leak was fixed.

Tom I have the same vehicle year make and model with the exact same issue with the front driver's side I'm on my 4th set up break caliber and rotor and 2nd mechanic still can't figure out the problem...I have about $2000 in break jobs in the past year! So if I try replacing the rubber hose like you did, will this work?