Sterling Trucks Acterra MX - Manual (Page 46)

6. Release the air pressure, then disconnect the
shop hose from the air inlet of the air cylinder.
Connect the vehicle air hose to the inlet.
7. Connect the electrical cables to the battery.
8. Start the engine.
Horton DriveMaster ® Fan Clutch
NOTE: If any part of the fan clutch needs to be
repaired or replaced after performing the checks
below, see Group 20 of the
Acterra ® Workshop
Manual.
1. Disconnect the batteries at the negative termi-
nals. Drain all air from the air system. If
equipped with an air starter, drain the air starter
reservoir.
WARNING
Make sure the batteries are disconnected before
checking the fan clutch. If the engine starts during
this procedure, the fan could engage, which could
result in serious personal injury.
2. Inspect the electrical connections and wires to
the fan clutch solenoid. Secure the connection if
loose; replace wires and connectors if damaged.
3. Clean the fan clutch air solenoid valve filter, if
equipped.
3.1 Unscrew the fan clutch solenoid valve air
filter assembly and remove the filter ele-
ment.
3.2 Clean the filter element with cleaning sol-
vent.
3.3 Using a clean, lint free cloth, wipe off any
excess solvent.
3.4 Reassemble the clutch valve solenoid air
filter assembly and install on the vehicle.
4. Visually check the fan for bent, cracked, or dam-
aged blades. Replace if damaged. Check for ad-
equate clearance between the fan and other
components.
5. Check the fan belt for wear, tension, and align-
ment. Correct, if necessary.
6. 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.
7. 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 the fan clutch from a dis-
tance. Look for vibration, fan blade contact, fan
clutch slippage, and overall fan clutch operation.
If the fan clutch does not operate correctly, see
Group 20 of the
Acterra ® Workshop Manual for
troubleshooting and repair procedures.
8. 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. See
Fig. 8 .
Using a wet finger or a soapy water solution,
check for a leak in the same areas.
9. If a leak is detected, remove the fan blade. In-
stall a new seal kit. See Group 20 of the
Acterra
® Workshop Manual for repair procedures.
f200237a
1
2
3
4
5
6
05/27/93
A
With the fan clutch engaged, measure the distance at A ;
measure it again with the fan clutch disengaged.
1. Bearing Housing
2. Retaining Plate
3. Fan Pulley
4. Air Inlet (from solenoid
valve)
5. Air Cylinder
6. Fan
Fig. 7, Kysor K22RA Fan Clutch Lining Wear Checking
Engine Cooling/Radiator
20
Acterra Maintenance Manual, January 2007 20/6