Western Star 47X 2020, Maintenance Manual

Page: 46 / 166

4. Check the fan belt for wear, tension, and align-
ment. Correct if necessary.
5. Check for wear on the friction facing. Replace
the friction facing if it is worn to a 3/16-inch (4.8-
mm) thickness or less. Also check the facing for
signs of oil contamination or burn marks. If evi-
dence of oil or burn marks are found, replace the
friction facing.
6. Connect the battery cables. Start the engine, and
charge the air system to 120 psi (827 kPa).
Manually engage and disengage the fan clutch.
Check the fan and fan clutch from a distance.
Look for vibration, fan blade contact, fan clutch
slippage, and overall fan clutch operation.
If the fan clutch does not operate correctly, repair
it.
7. With the air system charged to 120 psi (827
kPa), check the fan clutch for audible air leaks,
using a suitable listening device.
Check at the solenoid valve, the air filter assem-
bly, and the air hoses and fittings . Using a wet
finger or a soapy water solution, check for a leak
in the same areas. See
Fig. 6 and Fig. 7 .
8. If a leak is detected, remove the fan blade. In-
stall a new seal kit.
9. Check the fan drive for discoloration or any other
signs of slipping or overheating.
NOTE: The fan clutch may slip if the air supply
pressure is below 70 psi (483 kPa) or if there is
a leak inside the fan clutch. Any leak must be
remedied.
10. Check the fan clutch bearings as follows.
10.1 Turn the fan in both directions and feel
for worn hub bearings.
10.2 If possible, remove the drive belt and
check for worn sheave bearings by turn-
ing the sheave in both directions.
10.3 If either the hub or sheave bearings are
worn, replace them, using a Horton Drive-
Master Super Kit.
f200915 04/27/2020
A
4
3
2
1
A. MEASURE THIS DISTANCE TO DETERMINE
WEAR
1. IRON PULLEY
2. ALUMINUM SPRING
HOUSING
3. FRICTION LINER
4. FMFD
Fig. 6, Wear Measurement
f200914 04/27/2020
1
2
1. Pulley 2. FMFD
Fig. 7, Checking for Air Leaks (Horton DriveMaster)
Engine Cooling/Radiator
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47X and 49X Maintenance Manual, August 2020
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