Was driving at low rate of speed on side road. began to smell burning tire smell. pulled over and right front wheel was extremely hot, smoking, dripping burning white plastic looking material onto disk. got back in and drove to mother-in-law's house, approx three miles. still hot and appeared close to bursting into flame. tire and wheel smoking and stinking. brother in law hit caliper with a hammer to make it release. has not recurred. *tr