TM  10-3930-643-34 BRAKE  TROUBLESHOOTING  AND  MAINTENANCE.  (cont) 8-1. Service  Brake  Troubleshooting. MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION a. BRAKES DO NOT ENGAGE. Check brake calipers for evidence of oil leakage. Leakage indicates a faulty seal, refer to paragraph 8-4 for repair procedures. b. BRAKES DO NOT Check  treadle If repair 8-13. c. BRAKES SQUEAL RELEASE. and treadle valves for is necessary, refer to OR  SCRAPE. proper  operation. paragraphs  8-9,  8-10,  8-12  and Check for wear of brake liners. To repair service brakes, refer to paragraph 8-4. 8-2