Going back to first post I reported that I have replaced master cylinder, front caliper, new lines from proportioning valve to dist blocks on the drives side frame rail. new rear brakes and wheel cylinders, I have bench bled the master cylinder, and bled all brake lines. There is no air what so ever in the lines, i have good fluid coming out of each line. I still have abs and brake light on, and no brake pressure. I can put the brakes and no pressure builds but the pedal does rise back to top position. No air leakage coming from the brake booster. I have also replaced one power steering line going to the cooler, I have bled that as well. Looking at the proportioning valve the nipple is in the up position. Any help would be great.

 

did it behave this way with both master cylinders? the original and this new one?

 

my recent rear brake replacement:

after bleeding - the ABS light was on. a google search said to crank the truck, then press and hold the brake pedal for 10 seconds to allow the proportioning valve to recenter. this worked for me.

 

Yes, i replaced old one because the pedal went to the floor from mashing the brake pedal. Put new one in and i had some pressure, ended up replacing front calipers because every so often i would get a dragging feeling and the allen head screws werent holding the caliper tight to the rotor and the rotor would make a clunking noise when turning the wheel.

 

Have you checked the soft line by the fuel tank. I believe I've heard that they can devolp pin hole leaks or just wear out.

 

take a look at the rubber brake hoses from the spindle area to the front calipers. if they are old and soft, they may be swelling and absorbing the pressure. they're pretty cheap

 

Are you bleeding with the truck running? If so you will never get a pedal because you have boost. I drove myself crazy the last time I bled my brakes after replacing the master cylinder because I was conviced I had no pedal because I could push it to the floor. Boost is a powerful thing. Once it bled off from pumping the brakes with the engine off the pedal was rock hard.

 

Make your horn louder.

Hope this helps.

 

Seriously dude, why do you even bother posting here?

 

Hope you find the issue
I just replaced my soft lines and have no pedel
Everything except proportioning valve is brand new.