I have made 3 trips with my new to me 2006 F-250 towing a 27 ft TT. The brake control is a Ford factory installed unit whereas on my older F-250 I had an aftermarket Brake controller. On the previous 3 trips with the newer F-250, I set the Ford brake controller to 6 and I could feel the trailer braking behind me as it should. This latest trip, I could feel almost nothing in the way of trailer braking UNTIL I really pushed on the brake pedal or manually squeezed the buttons on the controller and then the trailer brakes would lock up. All indications on the controller were normal and the same as in the past. Those of you with this Ford system, is 6 what you are setting the controller at or is yours set higher? If at 6, what else could be causing this problem this time.. Do I need to readjust the brakes again? I am 99% positive that the brake shoes are in good shape (only 4500 miles on trailer) and that there is no grease on the shoes as the wheels were repacked (new seals) and inspected within the last 9 months. Appreciate any ideas or suggestions.