TOPIC 5. FAN AND FAN BELT

TM 10-3930-644-14&P

TOPIC 5. FAN AND FAN BELT

A. DESCRIPTION

The cooling fan (Figure 5-1) pushes air through the

engine radiator and helps to cool the engine water as it

circulates from the top to the bottom of the radiator core.

B. SERVICE

1. Fan blades seldom require service; however,

bent blades will affect the balance of the fan and

this is detrimental to the water pump bearing. A

fan which is bent will not cool as efficiently as it

was originally designed to perform. In the event

of damage, the fan should be removed and the

blades restored to their original contour or

replaced by a new fan assembly.

2. Periodic replacement of the fan belt is a good

safeguard against a damaged radiator and

unnecessary shutdowns.

NOTE

Attempting to force the fan belt over

the pulley while it is under tension is

almost certain to cause damage to

the pulley or bearings.

Figure 5-1. Fan Blade, Belt and Pulley (Typical)

C. REMOVAL

D. INSTALLATION

Fan Blade:

1. Remove the radiator.

1. Replace the fan blade and lockwashers and

tighten with mounting capscrews.

2. Loosen the alternator adjusting bracket

capscrew

and

the

alternator

mounting

2. Install fan belt and ensure that it is properly

capscrews and relieve the fan belt tension.

installed across all pulleys, including fan pulley

3. Remove the capscrews and lockwashers which

prior to final tightening of fan blade capscrews.

mount the fan on the fan pulley.

3. Force the alternator away from the engine with a

4. Repair or replace the cooling fan as required.

long-handled screwdriver or pry bar, until the fan

belt has approximately 1/2" to 3/4" deflection at

Fan Belt:

a point half way between the fan pulley and the

alternator pulley with about 10 lbs. applied force

1. Loosen the alternator adjusting bracket

(Figure 5-2).

capscrew and alternator mounting capscrews

and relieve the fan belt tension.

4. Tighten the alternator mounting capscrews and

the alternator adjusting bracket capscrew.

2. Slide the fan belt from alternator pulley and

fan

drive pulley. Remove fan belt from the

fan

5. Replace radiator.

(Refer

RADIATOR

pulley by sliding it off over fan assembly.

careful not to damage radiator when sliding

the

INSTALLATION Section.)

belt past the fan blades.

M-155-1

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