After turning on to the final approach for landing at his home airport, the pilot of the Piper PA-28-140 selected 25 degrees of flaps, and slowed to 80 miles per hour. At this point, he encountered a slight crosswind that was blowing from the east to the west. This caused the airplane to drift slightly to the right of the runway centerline but, he corrected for it. He stated that the touchdown was smooth but, the airplane began to veer to the right. The pilot tried to correct using left rudder and left brake but the airplane continued to veer to the right, departed the paved surface of the runway, and struck a runway sign with the left wing, substantially damaging the wing structure. After striking the runway sign the airplane traveled up onto a taxiway and the pilot released the pressure on the left rudder pedal. The airplane then ground looped to the right, travelled off the side of the taxiway, and rolled forward about 50 feet and came to rest. The pilot stated that he believed that the right brake may have been "hanging up" and that he should have aborted the landing when the airplane began to veer to the right. A review of witness statements did not reveal any evidence of a brake malfunction, nor did they reveal if the brakes were functioning properly at the time of the accident. A cursory visual examination of the airplane by a Federal Aviation Administration inspector did not reveal any break anomalies.