Drive Belts and Shafts

1-5.

Drive Belts and Shafts

1-6.

Pipes, Hoses and Connections

a. Belts (fig 1-2). The most common type of fan

The purpose of connection hoses and pipes is to isolate

the radiator from engine vibrations and to provide a leak

and water pump drive makes use of a single belt which is

proof path for adequate coolant circulation through the

driven by a pulley on the engine crankshaft Normally, this

cooling system components. Hoses are attached to the

belt also drives the generator. Other vehicles may have

various necks and flanges by clamps. Clamps may be

separate belts for one or two of these units, or two belts to

snap-on spring wires, screw type adjustable clamps,

drive a single unit In any case, proper operation of the

flange and gasket bolt-on joints or "O" rings. Leaks that

water pump drive belt is the most critical. When the water

are discovered at the hose clamp can often be repaired by

pump stops during engine operation, overheating of the

tightening when they are of the adjustable screw or bolt

engine follows almost immediately.

Belts stretch in

flange type.

service, adjustment of belt tension is by movable

mountings on one or more units driven by the belt.

1-7.

Miscellaneous Fittings

b. Shafts Some heavy-duty engines make use of a

shaft to drive the water pump Such a shaft is usually

a. Drain Cocks (fig 1-3) There is always a drain

driven from the engine crankshaft or camshaft by gears.

cock or removable screw-type plug located at the bottom

The shaft often drives the generator as well as the water

tank of the radiator or at the outlet to permit draining of

pump Flexible couplings are installed In drive shafts to

coolant. Similar points of drainage are provided for the

keep them properly lined up in their bearings.

engine block. In some systems, there will be a drain cock

or plug in the pump housing if it Is the lowest point in the

system. For complete draining of all parts of the system,

every coolant drain plug must be removed and every drain

cock opened.

Figure 1-3. Cooling system drain cocks

Figure 1-2. Fan, shroud and drive belt.

1-3