Finder9 wrote:
Regular grease. Was inspected by State inspection station prior to trip and passed, has been used for many long distance trips but this trip is a new tow vehicle with new brake controller.
this trip is a new tow vehicle with new brake controller.This caught my eye. If you have a powerful new tow vehicle towing a single axle trailer (which I am assuming the A-liner is?), the driver may not even realize if the trailer brakes are locking up or at least being applied too much (heat build up). Add to this a new brake controller that a person is not experienced with, and you might have the recipe for what you described happened.