My truck has had the exact same problems. I've had it die after parking it downhill while driving before, and I can easily come to a smooth stop with my power brakes, but after that, I can barley stop from a few miles and hour standing on the pedal...
2002 Red Mazda B2300
Short Cab, Short Bed, Pioneer sound system:
DEH-P5100UB deck, dual USB/aux inputs, single CD, organic display, remote
4 TS-A6872R 40 watt nominal speakers
2 TS-SW2501S4 250 watt nominal 10" subwoofers