TM 5-3895-346-14
WATER PUMP
ENGINE OVERHAUL
WATER PUMP
A centrifugal-type water pump (Fig. 1) is mounted on top of the engine oil cooler housing as shown in Fig. 2. It
circulates the coolant through the oil cooler, cylinder block, cylinder head, and radiator.
The pump is belt-driven by either the camshaft or balance shaft.
An impeller is pressed onto one end of the water pump shaft, and a water pump drive pulley is pressed onto the
opposite end. The pump shaft is supported on a sealed double-row combination radial and thrust ball bearing.
Coolant is prevented from creeping along the shaft toward the bearing by a seal. The shaft and bearing
constitute an assembly and are serviced as such, since the shaft serves as the inner race of the ball bearing.
The sealed water pump shaft ball bearing is filled with lubricant when assembled. No further lubrication is
required.
Figure 1. Water Pump Assembly
Figure 2. Typical Water Pump Mounting
Remove Water Pump
1. Remove the radiator cap, open the block and radiator draincocks, and drain the cooling system.
2. Loosen and remove the water pump belts.
NOTE
An idler pulley is used on some engines to adjust the water pump drive belt tension.
3. Loosen the hose clamps and slide the hose up on the water bypass tube.
4. Remove the five bolts securing the water pump to the oil cooler housing and take off the pump.
Disassemble Pump
1. Note the position of the pulley on the shaft so that the pulley can be reinstalled in the same position
when the pump is reassembled. Remove the water pump pulley as shown in Fig. 3.
2. Remove the pump cover and discard the gasket.
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