9802012 | Genuine International® Viscous Air Sensing Fan Clutch

1. Prevent Engine Overheating

• When radiator air temperature rises, the clutch engages.

• The fan spins faster.

• More air moves through the radiator to cool the engine.

This protects the engine from overheating damage.

2. Improve Fuel Efficiency

• When cooling isn’t needed, the fan partially disengages.

• The engine doesn’t waste power spinning a full-speed fan.

• This reduces fuel consumption.

3. Reduce Engine Noise

• A fully engaged fan is loud.

• When the engine is cool, the fan slows down.

• This keeps operation quieter.

4. Reduce Engine Wear

• Prevents constant high-load operation of the fan.

• Reduces strain on belts and pulleys.

5. Provide Reliable Cooling in Heavy-Duty Applications

Commonly used on:

• Diesel trucks

• Semi-trucks

• Work vehicles

• Vehicles that tow or haul heavy loads

It’s very reliable compared to electric fans in heavy-duty setups.

1. Engine Overheating

• Temperature gauge runs hotter than normal

• Overheats at idle or in traffic

• Overheats while towing or under load

This usually means the clutch is not engaging properly.

2. Fan Always Running Loud (Stuck Engaged)

• Loud “roaring” fan noise all the time

• Noise increases with RPM

• Poor fuel economy

This means the clutch may be stuck locked.

3. Weak or No Fan Engagement When Hot

When the engine is hot:

• You don’t hear the fan roar

• Airflow through the radiator feels weak

• Temperature keeps climbing

This suggests the clutch isn’t locking up.

4. Excessive Fan Free-Spin (Engine Off Test)

With the engine off:

• The fan spins very freely with little resistance

Some resistance is normal. If it spins too easily, the clutch may have lost its internal fluid.

5. Wobbling Fan

• Visible fan wobble

• Vibration from front of engine

• Possible bearing failure inside clutch

This is dangerous and should be fixed immediately.

6. Fluid Leaks

• Oily residue around the clutch housing

• Silicone fluid leakage

Loss of fluid means it can’t engage properly.

7. Poor Fuel Economy

If stuck engaged:

• Engine works harder

• MPG decreases noticeably