While driving I can hear a clicking sound coming from the driver's side front wheel. At speed 55mph, the "abs fault" signal appears, immediately followed by the "traction fault" signal, which both remain on until the engine is stopped. When engaging the brake pedal, the truck either responds appropriately, or goes through this cycle. Initially there's alot of resistance, a feeling of metal against metal, without brake response. The severity and duration is unpredictable. Once I've pumped the brakes enough times, it either responds appropriately or responds appropriately for a few seconds, disengages (goes soft) grinds, or clicks and engages again allowing me to stop.