TM   10-3930-643-20 BRAKE TROUBLESHOOTING AND MAINTENANCE. 8 - 1. Service   Brake   Troubleshooting. MALFUNCTION TEST OR INSPECTION CORRECTIVE   ACTION b . BRAKES DO NOT RELEASE. Check   treadle   and   treadle   valve   for   proper   operation. If   replacement   is   necessary,   refer   to   paragraphs   8-10   or   8-11. If   piston   in   caliper   is   frozen   or   stuck,   notify   Direct   Support. If   valve   is   bad   or   repair   is   indicated,   notify   Direct   Support. c. BRAKES SQUEAL OR SCRAPE. Notify   Direct   Support. 8-3