Specifications Of Fresh Water Pump; Fresh Water Pump Disassembly; Fresh Water Pump Inspection - Yanmar 3JH4E Service Manual

9.3.2 Specifications of fresh water pump

Pulley ratio
(crank shaft/pump shaft)
Pump shaft speed(Max)
Delivery capacity
Total head

9.3.3 Fresh water pump disassembly

(1) Do not disassemble the fresh water pump. It is difficult to disassemble and, once
disassembled, even more difficult to reassemble. Replace the pump as an assembly in
the event of trouble.
(2) When removing the fresh water pipe as an assembly from the cylinder and cylinder
head, replace the cylinder intake pipe O-ring.
(3) When the fresh water pump and pump body and cylinder intake flange and/or fresh
water pump and pump plate are disassembled, retighten to the specified torque.
Tightening torque for pump
setting bolts

9.3.4 Fresh water pump inspection

(1) Bearing unit inspection
Rotate the impeller smoothly. If the rotation is not smooth or abnormal noise is head
due to excessive bearing play or contact with other parts, replace the pump as an
assembly
(2) Impeller inspection
Check the impeller blade, and replace if damaged or corroded. or if the impeller blade is
worn due to contact with pump body.
(3) Check the holes in the cooling water and bypass lines, clean out any dirt or other
foreign matter and repair as necessary.
(4) Replace the pump as an assembly if there is excessive water leakage due to
mechanical seal or impeller seal wear or damage.
(5) Inspect the fresh water pump body and flange, clean off scale and rust, and replace if
corroded.
(6) Measure the clearance between the Impeller and the pump body, by pushing the
impeller all the way towards the body, and inserting a thickness gauge diagonally
between the impeller and the body.
Measure the clearance between the impeller and the plate (pump body bracket) by
placing a straight-edge against the end of the pump body and inserting a thickness
gauge between the impeller and the straight-edge.
Ø120/Ø120
-1
4020 min
70 L/min
4 m
687-1080 N•cm
(70-110 kgf•cm)
151
9. Cooling Water System