badboys

Hi all, just woundering if anyone has the same prob as me, which is brake performance My car is a ford galaxy mk2 1.9 tdi , year 2000=w Reg i have a real strange problem with the brakes, first of all let me try an explain myself about the brakes, well when i got the car the brakes were fantastic but know they are no where near as good, all i done was change the front brake pads! Now i'm left with half the brake power? So i would be grateful if anyone could tell me what to do, or try to find out why this is happening, I was reading on the forum about brake problem but i cant see anything that relates to my problem, the only one other thing that i have noticed is when i'm traveling alone the road and keep my foot slightly on the accelerator pedal and then press the brake pedal everthing in perfect, SO what could this be?? Vacuum lines or could be the diesel fuel pump? Many Thanks Badboys.