I have a 2001 Ford F150 Lariat with the 4.6L V8 Engine. Sometimes while I have my trailer hooked up I get a tremendous howling while braking. Almost so loud you can't hear anything else in the cab. The trailer I tow is about 350 lbs plus approximately 900 lbs of cargo. So the total weight is around 1250 lbs, well below the capacity of this truck.
This howling has only happened while towing. It isn't consistent and I can't reproduce it. What could cause this? I have a strong shudder while on the brakes, but I think that is just because of the left front rotor being warped.