Radiator Cooling Fan: Service and Repair
RADIATOR FAN 5.9L DIESELREMOVAL
CAUTION: If the electronically controlled viscous fan drive is replaced because of mechanical damage, the cooling fan blades should also be inspected. Inspect for fatigue cracks, or loose rivets that could have resulted from excessive vibration. Replace fan blade assembly if any of these conditions are found. Also inspect wiring harness and connectors for damage.
1. Disconnect the battery negative cables.
2. Remove the fan shroud lower half. by unsnapping the fastening tabs.
CAUTION: Do not remove the fan pulley bolts. This pulley is under spring tension.
3. Disconnect electrical connector.
4. The electronically controlled viscous fan drive/fan blade assembly is attached (threaded) to the fan hub shaft. Remove the fan blade/fan drive assembly from fan pulley by turning the mounting nut counterclockwise (as viewed from front). Threads on the viscous fan drive are RIGHT-HAND. A Snap-On 36 MM Fan Wrench (number SP346 from Snap-On Cummins Diesel Tool Set number 2017DSP) can be used. Place a bar or screwdriver between the fan pulley bolts to prevent pulley from rotating.
5. Remove the fan shroud and the fan blade/viscous drive as an assembly from vehicle from under the vehicle.
6. Remove fan blade-to-viscous fan drive mounting bolts.
7. Inspect the fan for cracks, loose or bent fan blades.
CAUTION: Some engines equipped with serpentine drive belts have reverse rotating fans and viscous fan drives. Installation of the wrong fan or viscous fan drive can result in engine overheating.
CLEANING
Clean the fan blades using a mild soap and water. Do not use an abrasive to clean the blades.
INSPECTION
WARNING: DO NOT ATTEMPT TO BEND OR STRAIGHTEN FAN BLADES IF FAN IS NOT WITHIN SPECIFICATIONS.
CAUTION: If fan blade assembly is replaced because of mechanical damage, water pump and viscous fan drive should also be inspected. These components could have been damaged due to excessive vibration.
1. Remove fan blade assembly from viscous fan drive unit (six bolts).
2. Lay fan on a flat surface with leading edge facing down. With tip of blade touching flat surface, replace fan if clearance between opposite blade and surface is greater than 2.0 mm (0.090 in.). Rocking motion of opposite blades should not exceed 2.0 mm (0.090 in.). Test all blades in this manner.
3. Inspect fan assembly for cracks, bends, or broken welds. Replace fan if any damage is found.
INSTALLATION
1. Install fan blade assembly to electrically controlled viscous fan drive. Tighten mounting bolts to 23 Nm (17 ft. lbs.) torque.
2. Position the fan blade/viscous fan drive to the vehicle as an assembly.
3. Install viscous fan drive assembly on fan hub shaft. Tighten mounting nut to 33 Nm (24 ft. lbs.) torque.
4. Connect electrical connector.
5. Install the lower fan shroud into position and verify the locking tabs have seated.
6. Connect the battery negative cables.
NOTE: Viscous Fan Drive Fluid Pump Out Requirement: After installing a new viscous fan drive, bring the engine speed up to approximately 2000 rpm and hold for approximately two minutes. This will ensure proper fluid distribution within the drive.