RE: 2004 silverado brake problems
you, probably, have several things going:
1. rusted, sticky caliper somewhere; it does not return and drags brakes.
2. master cylinder seals are swallen and do not return piston, allowing continuous pressure in the system resulting in - daaah, continuous brake drag
3. blockage in one of the brake lines, hence the hard pedal feel/ poor caliper return, resulting in - daahhh, dragging brakes.
you sure you brother added BRAKE FLUID, no something else? master seals will swell almost immediately if it has ANY machine oil in it. brake fluid is mostly alcohol and plant oil. used to be rycin oil.
anyways, bleeding helps with mooshie pedal, when you have air in the system. you have opposit.
now, here's my suggestion, and i do not have a good one for you: sounds like you are not familiar with brakes/repairs, as bleeding brakes is a very basic procedure known to any rookie mechanic. now, considering that your LIFE, and lifes of others depends on how well your brakes operate, i'd send this over to a pro shop. sorry, i am dead DIY, bu this is life threatening if not done right, so have someone who has "know how" do it for you.
i'd start with removing wheels and taking good look at rotors. one that is blue or blueish more that others - that's the one. also, wheel that is obviously hotter than the others after drive is on the bad side. from that point on, i'd start with removing caliper and overhauling it. disconnecting that side brake line and blowing it with compressed air. also, examining all brake lines for obvious damage, like bends, kinks, etc. life happens.
btw, is your parking brake fully disengaged?
2000 SILVERADO 1500 CENTURION EDITION, 5.3 VORTEC
DON'T FIX IT IF IT AIN'T BROK;
IF IT'S BROK, FIX IT RIGHT AWAY.