79 f350 d60s
the breaks just feel like, you know how when you grab a woman's breast... it feels like... a bag of sand... well thats what the breaks feel like. no but seriously, they dont stop the pickup worth shit. new master cylinder, new break booser, resurfaced rotars, new pads, rebuilt calipers up front. new shoes and drums out back. are the nearly thirty year old break lines expanding? or is it just gonna stop like shit? im only runnin 285/75s.

Have you tried bleeding the brakes??? to make sure fluid is flowing to all 4 brakes, and that there is no blockage anywhere?? 30 years old I could not imagine any rust or dirt every getting in the line. Do you have good vaccum to your booster?? Maybe I should rephrase that, does your motor carry good vaccum? That will make your brake pedal barely move "feel like a bag of sand"...there is not enough vaccum to make the booster work. I have 2 trucks that way...'77 f250's.

79 f350 d60s
the breaks just feel like, you know how when you grab a woman's breast... it feels like... a bag of sand... well thats what the breaks feel like. no but seriously, they dont stop the pickup worth shit. new master cylinder, new break booser, resurfaced rotars, new pads, rebuilt calipers up front. new shoes and drums out back. are the nearly thirty year old break lines expanding? or is it just gonna stop like shit? im only runnin 285/75s.

If you got break pads, shoes master cyl. etc etc. That could very well be your problem.

You need to trade that in for shit for your BRAKES.

P.S. If your womans tit feels like a bag of sand. Something is VERY VERY wrong.

yeah the engines got good vacume and i bled the breaks and theres fluid at all the corners but it just wont stop worth a piss.

change the prop valve
those are great Brakes so you have an issue somewhere

Are they in something stock or are they swapped into something else? & if so what's the master cylinder from?

was the MC bench-bled before being installed? If not, do that, then bleed the brakes and see what happens...

was the MC bench-bled before being installed? If not, do that, then bleed the brakes and see what happens...

X2 And check to make sure you don't need to adjust the push rod on the master cylinder, I've had to adjust all the ones I've installed.

a properly bleed and operating stock brake system should be more than adequate stopping power for your truck.