9. Cooling water system1639.3.3 Fresh water pump disassembly(1) Do not disassemble the fresh water pump. It is difficult to disassemble and, oncedisassembled, even more difficult to reassemble. Replace the pump as an assembly inthe event of trouble.(2) When removing the fresh water pump, replace the O-ring (inlet to cylinder).(3) When the fresh water pump and pump body and/or fresh water pump and pump plateare disassembled, retighten to the specified torque.9.3.4 Fresh water pump inspection(1) Bearing unit inspectionRotate the impeller smoothly. If the rotation is not smooth or abnormal noise is headdue to excessive bearing play or contact with other parts, replace the pump as anassembly(2) Impeller inspectionCheck the impeller blade, and replace if damaged or corroded or if the impeller blade isworn due to contact with pump body.(3) Check the holes in the cooling water and bypass lines, clean out any dirt or otherforeign matter and repair as necessary.(4) Replace the pump as an assembly if there is excessive water leakage due tomechanical seal or impeller seal wear or damage.(5) Inspect the fresh water pump body, clean off scale and rust, and replace if corroded.(6) Measure the outside clearance between the impeller and the pump body, by pushingthe impeller all the way towards the body, and inserting a thickness gauge diagonallybetween the impeller and the body.Measure the side clearance between the impeller and the plate by placing a straight-edge against the end of the pump body and inserting a thickness gauge between theimpeller and the straight-edge.Measuring outside clearance between impeller andpump body.Tightening torque for pumpsetting bolts392-785 N•cm(40-80 kgf•cm)mmStandard LimitOutside clearance betweenimpeller and body 0.3-1.1 1.5Thickness gauge
