SECTION 05: COOLING SYSTEM
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
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3. Unscrew and remove the universal joint shaft
mounting bolts (6 bolts) at the fan clutch.
4. Pull the shaft toward the rear of the vehicle.
5. Finally, dismount the universal joint shaft
from the fan drive pulley (6 bolts).
Installation of the universal joint shaft is the
same as removal, but in reverse order.
FIGURE 31: DISMOUNTING FAN DRIVE PULLEY
05123C
12.3 IDLER REPLACEMENT
If an idler is defective, replace as follow:
WARNING
Turn the ignition switch to the OFF position
and set starter selector switch to the OFF
position to prevent accidental starting of the
engine.
1. Remove the protective cap (replace with a
new one).
2. Unscrew the idler mounting bolt.
3. Replace idler with a new one.
CAUTION
When installing the idler, make sure it rests
perfectly against the bearing surface on the
cast aluminum support. If not, the drive belt
may slip of the idler. See following figure.
FIGURE 32: IDLER MOUNTED ON THE CAST ALUMINUM
SUPPORT
4. Bolt the new idler on the cast aluminum
support. Tighten as prescribed.
5. Place a new protective cap.
IDLERS
Ref
System
Torque lbs-ft
I-1
cooling fan drive
50
I-2
cooling fan drive
32
I-3
cooling fan drive
50
I-4
water pump drive
43
I-5
water pump drive
16 (pulley)
32 (shaft)
I-6
A/C compressor drive
60
I-7
A/C compressor drive
74
AUTOMATIC BELT TENSIONERS
Ref
System
Torque lbs-ft
T-1
cooling fan drive
32 (2x)
T-2
water pump drive
43
FIGURE 33: TIGHTENING SPECIFICATION (VOLVO D13
ENGINE)
13. VARIABLE SPEED FAN CLUTCH
The cooling fan clutch has two thermostatically
controlled speeds, plus a neutral (clutch
disengaged). The engine ECU controls the
speed by comparing data from engine coolant
temperature, charge air temperature, Allison
transmission oil temperature (if applicable) and
small A/C High side pressure to a set of
calibration data. The fan drive clutch is
electromagnetic; the engine control module
sends an electric current to regulate speed by
activating one magnetic coil for the first speed
and two magnetic coils for the second speed.
