TM  10-3930-643-34 ENGINE,  FUEL,  EXHAUST  AND  COOLING  TROUBLESHOOTING  AND  MAINTENANCE.  (cont) 4-1. Engine,  Fuel,  Exhaust  and  Cooling  Troubleshooting.  (cont) MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION k.  CRANKCASE  PRESSURE  TEST.  (cont) 4. 5. 6. 7. 8. Check oil in crankcase for proper level. Connect water manometer to orifice connector, as shown. Run  engine  until  correct  operating  temperature  is  obtained,  refer  to TM  10-3930-643-10. Run engine at high idle, observe manometer for two minutes and record  average  reading,  refer  to  Engine  Troubleshooting  if  there  is an average reading of above 5.5 inches of water. Remove orificed restrictor (6), three nuts (1), washers (2) and housing (3). 9. Install crankcase ventilation breather tube, refer to TM 3930- 643-20. 4-14