Figure 4-34. Water Pump

TM 10-3930-633-12

Screw

Gasket

Lockwasher

Pulley hub

Shaft and bearing assembly

Water pump assembly

Impeller

Pipe plug

Figure 4-34. Water Pump

4-66. Fan and Alternator Belts

of the fan belt at each engine lubrication period. It

is good preventive maintenance to replace a badly

a. General. The fan, water pump, and alter-

frayed, worn or cracked fan belt before it breaks

nator are driven by a matched set of two V-belts.

in operation.

A fan belt that is too tight will cause rapid wear of

b. Replacement and Adjustment. Refer to

the alternator or generator and water pump

figure 4-35 for details of belt adjustment. To

bearings. If the belt is too loose, it may slip,

replace the fan belt, loosen the attaching bolts at

preventing the water pump from properly cooling

each generator or alternator brace-to-engine

the engine or the generator or alternator from

mounting and pivot the alternator toward the

properly charging the electrical circuit. The fan

engine to gain slack needed to install the new belt.

belt is properly adjusted when it can be deflected

Remove the old belt. Position the new belt over

1/2-inch (13 mm.) with 25 lbs pressure applied

the fan pulley, over the crankshaft pulley, then

midway between the fan and alternator pulleys.

over the alternator pulley. Pull the alternator

Check this adjustment and inspect the condition