Horton DriveMaster® Fan Clutch

122SD mm 20.03.02

    Note: If any part of the fan clutch needs to be repaired or replaced after performing the checks below, see Group 20 of the vehicle Workshop Manual.

  1. Disconnect the batteries at the negative terminals.
  2. Inspect the electrical connections and wires to the fan clutch solenoid; see Fig. . Secure the connection if loose; replace wires and connectors if damaged.
    1. Air Filter Housing

    2. Solenoid Valve

    Fig. 1, Horton DriveMaster Air Solenoid Valve

  3. Clean the fan clutch air solenoid valve filter, if equipped, as follows.
    1. Unscrew the fan clutch solenoid valve air filter assembly and remove the filter element; see Fig. .
      1. Filter Element

      2. Filter Bowl

      3. Bleed Valve

      Fig. 2, Horton DriveMaster Solenoid Valve Air Filter

    2. Clean the filter element with cleaning solvent.
    3. Using a clean, lint-free cloth, wipe off any excess solvent.
    4. Reassemble the clutch valve solenoid air filter, then install it on the vehicle.
  4. 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. 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 evidence 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 fan clutch from a distance. 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 vehicle 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 assembly, and the air hoses and fittings. See Fig. . Using a wet finger or a soapy water solution, check for a leak in the same areas.

    Fig. 3, Checking for Air Leaks (Horton DriveMaster)

  9. If a leak is detected, remove the fan blade. Install a new seal kit. See Group 20 of the vehicle Workshop Manual for repair procedures.
  10. Check the fan drive for discoloration or any other signs of slipping or overheating.
  11. Note: The fan clutch may slip if the air supply pressure is below 70 psi (483 kPa) or if there is a leak inside the fan clutch. Any leak must be remedied.

  12. Check the fan clutch bearings as follows.
    1. Turn the fan in both directions and feel for worn hub bearings.
    2. If possible, remove the drive belt and check for worn sheave bearings by turning the sheave in both directions.
    3. If either the hub or sheave bearings are worn, replace them, using a Horton DriveMaster Super Kit; see Group 20 of the vehicle Workshop Manual.
Note:
F03,F14,F24,F30,F31
Document Number: 0000125437
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-06-26