On several occasions, a vehicle cut off our truck so driver had to slam on brakes. Brakes locked up and would not release and truck would not move. Driver had to turn off the truck, set and release the parking brake before they would release and allow him to move the truck. Put truck in brake shop (SW Brake and Alignment) and they replaced brakes lines, master cylinder, hydraboost and sensor and the problem is still not fixed and the shop mechanics are still able to reproduce this locking up and not releasing issue after having our truck for more than a month. They are putting our old parts back on and releasing the truck back to us because they cannot figure out how to fix this issue. This is a safety issue for driver and others on the roadway if truck is stuck and not able to be moved out of the roadway to safety while the truck is immobile.
NHTSA ODI 11591255