What is the AC Compressor?
An AC system has many parts: compressor, condenser, receiver dryer, evaporator, and hoses. The compressor, the “heart” of the car’s air conditioning system works like a pump taking refrigerant, (R-12 in older cars, R-134a in 1995 and newer cars) and pressurizing it, passing it along to the evaporator.
The AC compressor has numerous moving parts (including pistons and valves). These internal parts can fail, causing the AC compressor to stop functioning. It is common for the internal parts of the compressor to come apart and disperse metallic debris throughout the system. Consequently, it is a requirement to change the orifice tube and the receiver dryer when changing the compressor since some of the debris may have ended up there.
For an AC compressor to work, it needs a clutch, bearing, and an electrical connector. The clutch is driven by a drive/serpentine belt, which engages the compressor when you switch on the AC. The clutch can burn or the bearing can fail. If the bearing or clutch has failed, it is recommended that the compressor be changed. Sometimes changing the entire compressor with a remanufactured one can be cheaper than changing an individual clutch or bearings.
It is also common for the seals in the AC compressor to go bad. The compressor may start leaking refrigerant and/or the AC oil. If the seals no longer hold, you will need a new compressor, as the seals cannot be replaced. A compressor may also fail if there is sludge or debris in the air conditioning system. If there is sludge or debris, the hoses, evaporator, and condenser should be flushed to get rid of the contaminants. When it is not possible to flush the parts, you may need to replace those parts.
Facts to Note:
This service comes with receiver dryer and orifice tube. It is very common for metals from the compressors to go throughout the system and get caught in different components. If the compressor is replaced without the dryer and the orifice tube, it will ruin the new compressor and it will not be covered by the warranty from parts manufacturers.
How to Fix:
Check for pressure in the AC system.
Check for power and ground at the compressor.
If compressor is found to be faulty, remove the entire refrigerant.
Take out the compressor, receiver drier, orifice tube, and/or expansion valve.
Flush all foreign materials from the AC System.
Fix new compressor, receiver drier, and orifice tube.
Evacuate and recharge the AC system.
Leak check for any system leaks.
Check for proper operation of AC system.
The most common reason for an AC compressor to fail is leaky seals and inadequate lubrication. It is good practice to turn the AC on periodically so that the seals don’t dry up and stay lubricated. If you notice a change in the temperature of the air through the AC vents (not as cold as it should be), get it inspected.
Common signs indicating you may need to change the AC Compressor:
No cold air from the vents.
Clicking sound from under the engine.
AC not working.
Importance of this service:
In addition to your comfort, air conditioning systems add value to your vehicle. You should keep your AC fully functioning. In some systems, the hot and cold air is blended to achieve the desired temperature setting. In these cases, when the AC system fails, you will not only NOT get any cold air, but the entire temperature regulation is thrown off.