I have a 2000 f150 4x4. Yesterday I went over some bumps on a dirt road and when I went to stop the pedal went to the floor 2 x. The brake light didn't come on. Fortunately I was going slow enough to turn into the driveway where I was going and pumped the brakes 3-4 times and the pressure was fine again. Truck sat for half an hour, I came home and they are still fine ! What the heck was that all about ? thanks, Tom first time poster.