2nd Gen Non-Engine/Transmission 96 with MUSH brakes

[RAndrae]

I am at witts end with these brakes, been chasing it for a year, All new egr calipers, rotors, lines, pads, master cyl, rear anti lock valve, bled, bleeded and bleeded, reverse bled, pressure bled, pump bled, still like mush. And when the petal hits the closest thing to firm it bleeds off and goes near the floor. bad master????? this thing with a trailer on you can stand on the petal as hard as you can it aint stoppin. any ideas