I had a caliper bushing blow and lost brakes i changed both front calipers brakes and rotors. Now when i turn truck on i have only a little back brakes when the pedal hits floor its a 2008 silverado 1500 wt.iwas told it was the porportioning valves doing there job and they had to be reset but there are none on my truck. It has abs with dynamic rear porportioning. Ihave no lue how to reset it. Or if thats for sure the problem. The brakes were fully bleed and there is no oil leaks or oil in vaccuum booster

 

I'd try going on some gravel and locking up the brakes. Perhaps the ABS needs to work a few times in order properly proportion the brakes.

 

Yep, go use them hard, and see if that helps. Just do it in a safe place.

 

Hey....you said "...the pedal hits the floor...." Is that right? If so, it really sounds like you have a system full of air to me. That fits with the "Only a little bit of back brakes" part.

I had a buddy's little brother that swapped calipers on his '76 K1500 and put the left one on the right & vica versa. Had back brakes some of the time and front brakes never. They will fit but the bleeders are pointing down, not up. You can bleed them until you turn blue but they will never work.

Sooo....IMHO....go back to basics: Inspect the job and make sure the Bleeders are on the top of the calipers (I always do this . Open up the bleeders and let it flow, making sure your master cylinder stays full. Don't Pump The Pedal!!! The fluid will push the bubbles out of the system. Shut down the bleeders down farthest from the master cylinder first and closest one last. If that doesn't fix it, you may have to bench-bleed your master cylinder all over again. Otherwise you have a leak.