Horton Advantage® Fan Clutch

cen mm 20.03.000

Note: If any part of the fan clutch needs to be repaired or replaced, after performing the checks below, see of the Century Class Trucks Workshop Manual.

  1. Disconnect the electrical cables from the battery. Drain all air from the air system. If equipped with an air starter, drain the air starter reservoir.

    2. 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. 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.
    1. Unscrew the fan clutch solenoid valve air filter assembly and remove the filter element.
    2. Clean the filter element with cleaning solvent.
    3. Reassemble the clutch valve solenoid air filter assembly and install on the vehicle.
  4. Visually check the fan for bent, cracked, or damaged blades. Replace if damaged. Check for adequate clearance between the fan and other components.
  5. Check the fan belt for wear, tension, and alignment. Correct if necessary.
  6. Check for wear on the friction facing. See Fig.. Replace the friction facing if it is worn to a 1/16-inch (1.6-mm) thickness or less. Also check the facing for signs of oil contamination or burn marks. If evidence of oil or burn marks are found, replace the friction facing.

    1. System Sentry® Fuse

    2. Safeguard Hole

    3. Friction Facing

    4. Piston Friction Disc

    5. Air Chamber

    Fig. 1, Horton Advantage Fan Clutch

  7. Connect the battery cables. Start the engine, and charge the air system to 120 psi (827 kPa). Shut down the engine. Separate the halves of the fan solenoid connector. The fan clutch should engage.
    If the fan does not operate correctly, see of the Century Class Trucks Workshop Manual for troubleshooting and repair procedures.
  8. With the air system charged to 120 psi (827 kPa), and with the fan solenoid connector halves separated, check the fan clutch for audible air leaks, using a suitable listening device.
  9. If a leak is detected, remove the fan blade. Using a soapy water solution, check the fan clutch at the following locations to locate the source of the leak. Install a new seal kit. See of the Century Class Trucks Workshop Manual for repair procedures.
    1. Check for a leak at the bleed hole on the fan pilot. Air leakage means that the cartridge assembly ( Fig., Ref. 16) or face seal (Ref. 17) is damaged.

      1. Mounting Bracket

      2. Rear Sheave Bearing

      3. Inner and Outer Bearing Spacers

      4. Forward Sheave Bearing

      5. Sheave

      6. Friction Facing

      7. Journal Spacer

      8. Socket-Head Capscrew

      9. Rear Hub Bearing

      10. Bearing Spacer

      11. Splined Hub

      12. Forward Hub Bearing

      13. Piston Friction Disc

      14. Large O-Ring

      15. Locknut

      16. Cartridge Assembly

      17. Face Seal

      18. Small O-Ring

      19. Air Chamber

      20. Socket-Head Capscrew

      21. Stud Bolt

      22. Lockwasher

      23. Hexnut

      24. Piston Assembly

      Fig. 2, Horton Advantage Fan Clutch Components

    2. Check for air leaks between the air chamber and the piston friction disc. Air leakage means that the large O-ring (Ref. 14) is damaged.
    3. Check for air leaks around the safeguard hole on the piston friction disc. Air leakage means the small O-ring (Ref. 18) is damaged.
    4. Check for air leaking from the System Sentry® fuse. Leaking air means the clutch has gotten so hot the lead alloy in the fuse melted. This released the clutch before the heat could damage the clutch bearings. Before replacing the fuse, find and repair the source of the heat.
  10. If equipped with an override toggle switch on the dash, check the fan clutch operation as follows:
    1. Connect the halves of the fan solenoid connector.
    2. Turn the air conditioner off.
    3. Start the engine and charge the air system to 120 psi (827 kPa). Tests must be performed with the engine temperature below 205°F (96°C) for Caterpillar engines, and below 200°F (93°C) for Cummins and Detroit Diesel engines.
    4. Set the toggle switch to the ON position; the fan clutch should engage.
    5. Apply the foot brake, and release the parking brakes.
    6. Set the toggle switch to the AUTO or OFF position; the air should exhaust and the fan clutch should disengage. Replace the switch if necessary.
  11. If the fan stays engaged at all times on a Detroit Diesel engine, check the circuit breaker labeled "engine fan."
Note:
Parent topic: Fan Clutch Check (Noise Emission Control)
Document Number: 0000121902
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-06-04