Did you bleed the system with a scan tool? If not, you didn't do a thorough job.Yes i just bled them and the pedals soft. I think it might be the booster and master cyclinder.
Why suspect the booster when the problem is a low pedal?
Does the truck stop? What is the history of this? Low brake fluid level? Why were the rear cylinders changed--did they leak? Front pads worn-out? How many miles since the previous brake work?