VMaster Air Sensing Viscous Fan Clutch

The VMaster viscous air-sensing fan clutch (fan drive) works smarter so your engine can work harder.

Equipped with a bimetal precision sensor, the viscous air-sensing fan clutch delivers the right amount of cooling required. A fan that operates at maximum speed only when cooling requirements demand it can cut fuel costs significantly over the life of the vehicle.

Modulation enables the clutch to regulate the fan speed between idle and maximum rotational speed depending on the air temperature, quickly responding to even small temperature fluctuations.


  • Heavy-duty trucks
  • Medium-duty trucks
  • Light-duty trucks
  • Automotive
  • Variety of off-highway equipment

Features & Benefits

  • Bi-metal precision sensor provides precision cooling for fuel economy and reduced noise
  • Modulation enables clutch to regulate fan speed with minor temperature fluctuations preventing system-damaging temperature spikes
  • Lightweight, modular and fully-sealed construction for long product life
    Stable crankshaft eliminates need for vibration damper for smooth operation

Viscous air-sensing fan clutch from Horton Sachs are equipped with a temperature sensor, which constantly senses the coolant temperature indirectly.

At low temperatures, the viscous air-sensing fan clutch runs in no-load operation and at high temperatures, it turns on. The fan, driven by the fan clutch, achieves the maximum speed and provides the radiator with the necessary airflow and cooling.

The viscous air-sensing fan clutch prevents the constant and often unnecessary running of the fan, and it clutches the fan only when necessary. A fan that operates when needed may result in fuel saving up to 10,000 liters (2,500 gallons), depending on the lifespan of the vehicle.

Read more at Horton.


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Norman G Clark - Horton VMaster Air Sensing Viscous Fan Clutch

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Viscous fan drive utilising a bimetal precision sensor which modulates fan speed based on temperature of air through the cooling package.

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