[GreenSnakeDoc]

I've put about 4 quarts of DOT 3 fluid through by brake system and still have a bubble someplace. Master Cylinder was "bench bled" in place using the plastic screw-in fittings and "U" shaped clear plastic tubes that dumps the fluid back into each resevoir. I've gone over all connections and tightened them to the limit allowed by a 3/8" line wrench. So, now I'm wonder if the two vertical loops are allowing air pockets. They are both down low along the left frame rail. One is the line from the master cylinder that bends upward, then down, like an upside down "U" before going into a tee. The tee is oriented with its openings at 12, 3 and 6 o'clock. 12 is the inlet, while 3 sends a line to the Left Front caliper. The line exiting at 6'oclock heads down, then quickly bends upward to the midpoint of the tee before turning downward and running horisontally along the frame rail. Both front lines run horizontally parallel before bending upward to clear the front cross member on their way to the calipers. I might br grasping at straws here, but I've followed every bit of advice on brake bleeding found in this forum: fittings tightened as hard as possible, calipers tilted backwards to put the bleed hole at 12 o'clock, tapping the calipers with a hammer, rasing the front end a few degrees, pushing slow and realeasing slow on the brake pedal. Thanks for any opinions or additional thoughts you may have.