Got 06 f-250 6.0 powerstroke 4x4. A few months ago the caliper starts leaking like crazy after driving it for a while, so I replaced the caliper (53,000 miles on the truck) on the drivers rear, about 2000 miles later same caliper starts leaking again. Replaced the caliper today and now I have bleed all four corners and still cannot get pedal pressure. All calipers are shooting out all fluid no air, but as stated the pedal will not get hard. When you start the truck there is no pedal pressure at all. We bleed them with the cap on the master and then again with the cap off. I currently have a TBC fault but that shouldn't mess with the brakes should it? The caliper came from NAPA and its a Ford/TRW unit. Please help !