This is the second Ford truck I had the same problem with! my first was a 92 F250 and any given time the brake light would come on and soon after when i pushed the brakes they would not release. My current F350 Powerstroke is now doing the same thing, Brake light is on and off, on and off, for the past week. Well today they decide to lock up after I picked up the kids from school. The rear drums would not release and would hold pressure at the point i let off the brakes. Some other threads i looked through are saying the ABS valve somewhere under the truck can be bypassed with a union and should eliminate the whole problem. Is this safe?

 

Anyone with the same issue, I replaced the RABS valve located on the frame near drivers floor board and problem was solved. Cost was about 200 bucks