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AIR CONDITIONING
COMPRESSOR CLUTCH

When you turn your air conditioning on, the A/C compressor clutch is the first part to move. If your air conditioning isn't working properly, you may need to replace the A/C compressor clutch to fix the problem.

Install Level of Difficulty

MODERATE

What is an A/C Compressor Clutch?

When the A/C is switched off, the pulley on the A/C compressor spins freely. This frees up power and increases fuel economy when the A/C is not being used. When the A/C is activated, the compressor clutch transfers power from the engine’s crankshaft to the pulley mounted on the A/C compressor.

How does an A/C Compressor Clutch Work?

Air conditioning is a power intensive process, and it takes a lot of power from the engine for it to work effectively. By using a clutch mechanism, engineers designed A/C systems that don’t have to be on all the time. Using a clutch mechanism to connect the compressor to the engine not only increases fuel economy, it also increases the useful life of the vehicle by reducing stress on its engine.

How are A/C Compressor Clutches Made?

Some A/C compressor clutches are replaced individually, while others are included with the compressor assembly. There's no need to purge and fill any refrigerant when the pulley is replaced by itself, making replacement a moderately difficult project for the average DIY mechanic. The clutch consists of two primary parts, an electromagnetic coil and some type of friction disk. Magnetic forces created by the coil push the friction into the clutch assembly, forcing the compressor to rotate with the engine's crankshaft.

Why do A/C Compressor Clutches Fail?

  • Oil, debris, dust, heat, moisture, and simple wear and tear may cause the friction material to wear out and fail.
  • The bearings inside the clutch and compressor housing wear out and fail.
  • Improper installation of brackets, belts, and tensioners may increase stress on the compressor clutch and assembly.

What are the Symptoms of A/C Clutch Failure?

  • The pulley may become frozen on the compressor. A loud belt squealing noise is often heard when this symptom is present.
  • The pulley may feel loose, crunchy, or gritty after removing the belt and turning it by hand.
  • The A/C compressor clutch fails to engage the compressor when the A/C is activated.
  • Inadequate A/C system pressure.

What are the Consequences of A/C Clutch Failure?

  • The belt driving the A/C compressor may wear out prematurely if the A/C compressor becomes seized.
  • The serpentine belt may break suddenly if a seized A/C compressor or clutch is not replaced promptly.

There's no point in running the compressor when the A/C isn't needed, which is why there's a clutch mechanism present to connect and disconnect the compressor from the engine’s crankshaft when it's not in use. If you're not sure what's wrong with your vehicle's air conditioning, schedule an appointment with your local Pep Boys before summer arrives.


If you have questions or concerns about air conditioning compressor clutches or any of your vehicle's components, come into your local Pep Boys where we can answer any question, help you find any part, or perform any vehicle service you might need.