I have a 97 Ram 1500, 5.2 liter and the brakes seem real soft. When the brake is first applied, there is good pressure and firmness but if I have to stay on them, like at a light, by the time the light is green, I'm all the way to the bottom and sometime even have to let it all the way out and re-engage the brake, or it will start creeping forward again. I have bleed all for and still the same thing. I am thinking that the next step might be to replace the booster. Has anyone had this problem and or have any info or advice on what may be the problem at hand. Appreciate any help.
Thanks.

 

sounds master-cylinderish..the booster is good if the pedal is not super-hard

 

Either the master cylinder is bypassing or youhave a wheel cylinder starting to go........but I'm betting master