Repair and replacement of the A/C compressor

The air conditioner is the main component of a vehicle’s climate-control system. It ensures a comfortable ride for the driver, especially during the summer.

The A/C compressor is driven by the engine belt. However, until the electromagnetic clutch is engaged, the pulley’s rotation is not transmitted to the compressor.

Signs that the A/C compressor is faulty and needs repair

• Strange humming or rattling from under the hood

At first the noise may be barely noticeable. Over time it becomes louder, indicating that the A/C compressor needs repair.

• No click is heard when you switch the unit on

This means the electromagnetic clutch does not engage and the mechanism does not couple with the pulley.

• Low pressure in the discharge line

This occurs because the mechanism has reached the end of its service life or because of excess/insufficient refrigerant.

• The compressor has seized, the front drive part is missing, and the shaft does not rotate

This mechanism is very sensitive to external factors. Most often the cause of climate-system failure is a lack of refrigerant. Proper and timely diagnostics reveal all shortcomings and let you fix them with a light repair or simply by recharging the system with refrigerant.

Other common causes of compressor failure include contamination, too little or too much oil, incorrect oil, scale, fine shavings, and loss of sealing.

Such issues can clog the entire air-conditioning system. In that case, the only option is to remove the compressor, dismantle it, and perform a full wash and cleaning.