ENGINE, FUEL, 4-1. Engine, TM  10-3930-643-34 EXHAUST  AND  COOLING  TROUBLESHOOTING  AND  MAINTENANCE. Fuel,  Exhaust  and  Cooling  Troubleshooting. MALFUNCTION TEST  OR  INSPECTION CORRECTIVE  ACTION k.  CRANKCASE  PRESSURE  TEST. 1. Remove crankcase ventilation breather tube and thoroughly clean breather  element,  refer  to  TM  10-3930-643-20. 2. 3. Install new gasket (5), clean breather element (4), housing (3), three washers (2) and nuts (1) on valve cover in place of standard breather tube. Connect orificed restrictor (6) to housing (3) and secure with hose clamp. 4-13