Ok this is the deal. i have a 97 ram 4x4 5.2 i have literally changed everything ne calipers new master there are no leakes in the lines everything bleeds well. i still have nothing i dont understand i am replacing the booster in the morning but i honestyly dont think that is the issue if you can geive me some advice it would be greatly appreciated. thanks matt

 

what exactly is wrong? You stated what you did but not what it's doing...

 

Not sure what your specific issue is, but the pre 99 or 2000 Rams with the single piston caliper and the 11.6" rotors SUCK ****.

The brakes on these trucks should be recalled!!! I just got mine back from getting axle seals put in, and i had the guy look at my brakes. he said he can't find anything wrong.
but yet they just suck. I tried all that I am willing to try (running out of cash).

best of luck with your 1/2 tun turd.

 

basically i changed all of the things i mentioned and now i press on the pedal and there is nothin no pressure i guess. when the truck is off they will pump up and get hard while i bleed it but as soon as i start the truck there is nothing the pedal goes all the way to the floor. i thought maybe it was just soft but i put it in reverse and i still couldnt stop i checked all the lines and no leakes. everything blead fine i have couple buddys who are techs and they are racking there brains

 

try replacing the proportioning vavle and the abs unit it goes there first after the master cylinder and change your frt and rear rubber line's to stainless steel line's they give you a stiffer pedal and more pressure to the brakes if there still stock its time to change

 

ok i guess my real question is what to do next if i have replaced the calipers and the master and the resevoirs in the drums and all pads. Do i replace the booster or do i have someone do a pressure test on the lines and if so could i test it myself or if you have something else in mind just let me know this is my only vehicle and i need to get to work so anything is appreciated thanks again

 

Take the Master-Cylinder off & bench-bleed it again,..
You DID bench-bleed the thing before you put it on, right?

 

I had the same proplem and I took the master off and took it back to a local owned parts store ( not A/z ) swaped it for a new one bench bled it reinstall and problem was gone .BTW I completeluy replaced the old fluid while I was at it . Fluid was very nasty .

 

if there arent any leaks then you have air trapped somewhere.A reverse bleed might help you,like a phoenix injector sold on tool trucks,but stop replacing parts and find the problem,

 

Don't replace the lines. You said the pedal pumps to a firm pedal when the truck is off. It's when you put a vacuum on it (engine running) that it drops to the floor. That doesn't have anything to do with the lines or anything at the wheels. And I doubt the proportioning valve. There's something with the power booster and the master cylinder. There's a hose that runs from the engine to the power booster. Remove it from the power booster and see what happens when the truck is running.