When i got my truck the brakes where soft from day one but still stopped good. so i started with M/C and booster didn't make much difference following week i replaced everything front brakes because one of the rubber lines where questionable and flushed all fluid. Didn't seem to make it better but seemed worse. So I went right then and bought all new rear stuff (AND HELD A BILL OFF TILL THE FOLLOWING WEEK) and after that they was great so then i was wanting to know why my rears made so much of a difference and took my air hose and blew air through the rubber line and if i moved it around it would quit letting air go through cause it was deteriorating from the inside.
So you sitting there saying rears dont make a difference I call that bullshit because my rears where still hooked up with restricted pressure and there was no way in hell i'd drive it because the pedal was to soft and spongy. So i can only imagine having no rears at all.
EDIT: Also i didn't have to worry about replacing rusted lines because its been a southern truck all its life, And around here a roll of brake line is $20-25