freightliner COLUMBIA CL112 Maintenance Manual page 48

Engine Cooling/Radiator
Kysor K22RA Fan Clutch
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
If the engine starts during this procedure, the fan
could cause personal injury. If the vehicle is
equipped with an air starter, be sure that the air
starter reservoir is drained.
2. Measure the distance from the back surface of
the fan clutch retaining plate to the forward-most
edge of the fan belt pulley. See
1
4
5
6
05/27/93
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)
Fig. 7, Kysor K22RA Fan Clutch Lining Wear Check
3. Disconnect the line from the air inlet of the air
cylinder. Connect a shop air hose to the inlet.
4. Apply a minimum of 100 psi (690 kPa) air pres-
sure to the air cylinder—the bearing housing will
move backwards, disengaging the clutch. Again,
measure the distance from the back surface of
Columbia Maintenance Manual, January 2007
Fig. 7, Ref. A.
3
2
A
f200237a
5. Air Cylinder
6. Fan
the retaining plate to the forward-most edge of
the fan belt pulley.
5. Compare the two measurements; if the difference
between the two measurements exceeds 0.150
inches (3.8 mm), the clutch lining is worn and
must be replaced. See Group 20 of the
®
Columbia Workshop Manual for clutch lining
replacement instructions.
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 battery cables. Start the engine.
Horton DriveMaster
NOTE: If any part of the fan clutch needs to be
repaired or replaced after performing the checks
below, see Group 20 of the Columbia
shop 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, then install it on the vehicle.
20
®
Fan Clutch
®
Work-
20/7