TN  10-3930-643-34 BRAKE  TROUBLESHOOTING  AND  MAINTENANCE.  (cont) 8-1. Service  Brake  Troubleshooting.  (cont) MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION d. LOW AIR PRESSURE. (cent) Step 7. Inspect air compressor parts for wear. Repair  compressor,  refer  to  paragraph  8-14. e. HIGH AIR PRESSURE. Inspect  governor  for  proper  operation. If necessary, repair,   refer to paragraph 8-15. f. NOISY  COMPRESSOR. Check oil supply line for restriction. If restriction is found, check for damage. Repair or replace if necessary. Inspect crankshaft and connecting rod bearings for burns or wear. Replace if necessary, refer to paragraph 8-14. 8-4