TM 5-3895-383-24 4. Porosity in fuel filter base Check  the  fuel  filter  base  for  porosity  or  defects. Fuel can be transferred to the crankcase through a defective fuel filter base. 5. Defective seal in the fuel transfer pump Check for a defective O-ring seal between the fuel transfer pump and the governor housing.  Refer to Disassembly & Assembly, in this service manual. Problem 35:  Fuel In Coolant Probable Cause: Defect In Cylinder Head Sleeve 1. Defect in cylinder head sleeve: Remove    unit    injectors    and    inspect    sleeves    in cylinder head injector bores.  Look for any signs of cavitation  erosion  or  cracks.    If  any  problems  are seen,   remove   the   sleeve   and   replace   with   new parts. Problem 36:  Loss Of Coolant A.  Outside Leaks (Go to Step 1) Probable Cause(s): Leaks in Hoses Or Connections Leaks In The Radiator And/Or Expansion Tank Leaks In The Heater Leaks In The Water Pump Cylinder Head Gasket Leakage B.  Coolant Leaks At The Overflow Tube (Go to Step 6) Probable Cause(s): Defective Pressure Cap Engine Runs Too Hot Expansion Tank Too Small Cylinder Head Gasket Leakage Or Crack(s) In Cylinder Head Or Cylinder Block C.  Internal Leakage (Go to Step 10) Probable Cause(s): Erosion Or Crack(s) In Injector Sleeves Cylinder Head Gasket Leakage Crack(s) In Cylinder Head Crack(s) In Cylinder Block A.  Outside Leaks Probable Cause(s): 1. Leaks in hoses or connections: Check all hoses and connections for visual signs of leakage.  If no leaks are seen, look for damage to hoses or loose damps. 2. Leaks in the radiator and/or expansion tank: Put pressure to the radiator and/or expansion tank wit the 9S8140 Cooling System Pressurizing Pump Group and check for leaks. 3. Leaks in the heater: Put pressure to the cooling system with the 9SB140 Cooling    System    pressurizing    Pump    Group    and check for leaks. 4. Leaks in the water pump: Check the water pump for leaks before starting the engine, then star the engine and look for leaks.  If there are leaks at the water pump, repair or install a new water pump. 5. Cylinder head gasket leakage: Look  for  leaks  along  the  surface  of  the  cylinder head gasket.  If you see leaks, install a new head gasket.    Tighten  the  bolts  that  hold  the  cylinder head according to the Specifications Section of the Service Manual. B.  Coolant Leaks At The Overflow Tube Probable Cause(s): 6. Defective pressure cap: Check the sealing  surfaces of the pressure cap and the radiator to be sure the cap is sealing correctly. Check  the  opening  pressure  and  sealing  ability  of the  pressure  cap  valve  with  the  9S8140  Cooling System Pressurizing Pump Group. 6-53