Issues addressed in the material:

  • What role does a compressor play in a car’s air conditioning system?
  • What signs indicate a malfunction of the air conditioning compressor
  • How much does it cost to replace an air conditioning compressor in a car
  • How to determine the malfunction of the air conditioner when buying a used car

For the comfort of the driver and passengers in cars, various components and assemblies are responsible, which sometimes require replacement. An air conditioner is one of such nodes that deserves special attention, since it saves a person from the summer heat and makes the trip as comfortable as possible. This unit, like any other part of the car, needs periodic maintenance and repair. In this article, we will consider situations when the replacement of an air conditioning compressor is required and how this happens.

What role does the compressor play in the air conditioning system process

airconditioner system

The ventilation system in the car interior cannot by itself cool the air to the required temperature. When the ambient temperature is above 20 ° C, then for the comfort of the driver and passengers it is required to lower it. This task is performed by air conditioning systems.

The air conditioner is appreciated by those who constantly use the car, because it creates coolness in the cabin in the hot summer, and also warms in the winter, warming up the interior before the trip. Also, the air conditioner, in addition to all its functions, purifies the air. Its components are constantly interacting with heating and ventilation systems. The main function of the air conditioner is to create a micro climate that is favorable for everyone in the car.

One of the main elements of the air conditioner is the compressor, which is involved in the operation of the cooling or heating system. Some car air conditioners have a receiver collector that serves to protect the compressor by evaporating the refrigerant. If there is no such addition, then under the hood of the car there should be hot space. This ensures the required level of evaporation of the coolant in the return pipes, as well as in the evaporator.

The car air conditioner is a completely sealed system filled with refrigerant gas and compressor oil. The oil is used to lubricate all the rubbing Audi parts involved in the work. In this way, wear of the moving parts of the compressor is reduced and gaps are sealed. In addition, the oil removes part of the heat generated by the friction of parts, and removes small particles from the equipment. During the circulation in the air conditioning system, the oil is mixed with refrigerant gas.

The system includes the following elements:

  • compressor;
  • condenser;
  • evaporator;
  • fan;
  • safety valve;
  • receiver-dryer;
  • expansion valve;
  • evaporative fan

diagram of car air conditioning system

The joint work of all elements of the cooling system leads to the fact that a favorable microclimate is created in the passenger compartment.

Automotive Air Compressor Diagnostics

The car air conditioning compressor works on the same principle as a domestic refrigerator. Their device is very similar. The car air conditioner and refrigerator work thanks to this main unit.

Often, even experienced drivers are mistaken, claiming that the compressor does not require attention and is the most reliable component of an air conditioner. Such beliefs lead to the fact that he begins to work not as before and may require the replacement of some elements. An example is the buzz when you turn on the air conditioner.

The sound of a running engine interferes with determining the source of noise. If the driver does not take any measures, this unit will soon become inoperative and may require expensive repairs or replacement of the air conditioning compressor.

aircon compressor

Malfunctions can occur both during external inspection, and by determining the characteristic noise during operation of the air conditioner:

  • Refrigerant leak – one of the reasons may be leakage through the stuffing box or gasket at the joints of the unit. Leaks of are clearly visible in the light of a UV lamp, but first you need to add fluorescent paint to the refrigerant.
  • The noise during operation of the air conditioner, as well as when it is turned off, indicates that replacement of shaft bearings or drive pulley is required. With such sounds, it is worth checking to see if the belt is too tight. In the case when, when the electromagnetic clutch is disconnected and the belt is loosened, the compressor pulley still manually rotates or wedges, then the problem is in the bearing, but if it rotates easily, then most likely the shaft bearing will buzz.
  • Failures of the electromagnetic clutch may be indicated by the absence of a click when the air conditioner is turned on. The reason is the appearance of a large gap between the pressure plate and the pulley, arising from the development of the coupling or in the case of melting of the coil from overheating of the compressor.
  • A loud knock or rumbling during operation indicates bent valves or worn working surfaces of the piston group. Inconsistency of the pressure measured at the inlet and outlet of the compressor with the nominal values ​​is also a sign of this defect.

In some cases, a full replacement of the AC compressor may be required. Such a need arises when the air conditioning system was improperly mounted or the operating rules were not followed.

Sorting the compressor of the car air conditioner in such cases makes no sense. When refrigerant leaks, auto mechanics typically replace filters, repair leaks, and charge the system.

But most often, such a malfunction is eliminated in a more efficient way, since depressurization of the system leads to moisture ingress, which means that it must be rinsed and, in some cases, disassemble and clean all components exposed to aggressive dirt and moisture, as well as replace the refrigerant.

How much does it cost to replace an air conditioning compressor

checking aircon pump compression

Many cars of foreign manufacture (Suzuki, Mitsubishi, Honda, Chevrolet, etc.) are equipped with complex systems. At the service station, auto mechanics can perform work on replacing an air conditioning compressor, the price of which will be about Z – 5 thousand rubles or more, depending on the nature and complexity of the work performed.

The exact numbers will tell you the master after diagnosing the condition of the car.

What operations are included in the replacement of an automobile air conditioning compressor and are they needed?

The bulk of the repair work, as a rule, falls on flushing the system, without which the successful operation of the air conditioner is not guaranteed. In well-established auto repair shops, a similar procedure is carried out for the reason that due to partial destruction a lot of mechanical particles get into the system, polluting it. Replacing the air conditioning compressor with your own hands without flushing leads to the fact that newly installed equipment quickly becomes unusable.

Mud and oil, when mixed, create such a corrosive mixture that flushing the system is complicated and must be done very carefully.

In auto service centers, special solvents and the corresponding equipment are used for these purposes, therefore, this operation is almost impossible to carry out independently.

When replacing the compressor of an air conditioner, the following required installation work can also be performed on equipment such as:

  • receiver-dryer;
  • a radiator of an air conditioner or, as it is also called, a condenser.

The first acts as a filter of the air conditioning system, which means it is destroyed in case of malfunctions of the old compressor. The second consists of thin tubes, which are easily clogged with an oily mixture with metal particles. Under the influence of high temperature, such a mixture quickly solidifies, and washing of this element becomes impossible, so it is better to buy a new spare part and replace the old one.

Before giving your car for repair, check with the service center whether the system is charged with refrigerant at the stated cost.

What else is changing in the car air conditioner

  1. Compressor Pulley Bearing Replacement Noise during operation, abrasions or other defects in the belt drive indicate that replacement of the bearing in the compressor of the air conditioner is required. In both cases, a buzz can be heard even when the air conditioner is off, but the engine is running.

    If the replacement is not made at the first manifestation of the malfunction, then this can cause unpleasant consequences. Overheating of the bearing most often leads to the fact that the electromagnetic coil, which provides the movement of the coupling, fails and also requires replacement. The bearing seizes and the compressor cover breaks, and from the end the device is covered with many cracks. But even with an entire cover, depressurization will lead to refrigerant leakage, which also provides lubrication to the compressor shaft (freon is mixed with special oil).

    All this threatens shaft overheating, and the compressor may catch fire, and then the entire unit will need to be replaced.

    The situation with a skew pulley is not excluded, which leads to uneven wear and jamming of the compressor. It is also possible to break the belt, from which electrical wires can be severely damaged. To prevent all of the above from happening, it is necessary as soon as possible to replace the defective bearing.

  2. Replacing the air conditioner compressor sealOften, the replacement of the air conditioning compressor seal is required. It is located on the back of the shaft and undergoes intense heat during operation. To replace it, remove the compressor and drain the refrigerant. Using a puller, remove the clutch, pulley and magnet. We clear of the remains of oil and dirt.

    Next, remove the snap ring. The device for extracting the shaft is installed on the shaft and by moving inward of the sock we touch the shaft seal. We rotate the handle clockwise, remove the gland with the help of an auxiliary device. We replace the compressor air conditioning oil seal and install the part in its place.

  3. Antibacterial cleaning of the air conditioner evaporatorIn order for your car to smell pleasantly when operating the air conditioner, you must periodically clean the evaporator. The recommended frequency of cleaning the air conditioner is once every six months. To do this, you need to purchase a spray cleaner for a car. Its contents are sprayed so that the substance enters the evaporator.

    At the same time, the re-circulation mode is switched to maximum speed. The film formed on the evaporator under the action of a spray protects against external influences, and also serves as preventive protection against germs and pests. In order for the car air conditioner to work more efficiently, you should turn it off a few minutes before arrival, that is, without waiting for the end of the trip. This measure allows you to dry the evaporator and extend the life of the air conditioner and compressor.

How to check the air conditioner when buying a used car

checking engine

Repairing a faulty car air conditioner can cost a lot of money. Depending on the manufacturer of the car and the year of its release. It is best in the very first days after the purchase to make a diagnosis with specialists who will always tell you in which cases it is necessary to replace the elements. If this is not possible, then do the inspection yourself.

Here are some tips: wait until the outside temperature reaches +15 degrees, turn on the air conditioner and set its regulator to minimum. Soak for 5 minutes with frontal blowing mode (recommended) and mid-position of the fan. The air temperature from the deflectors should be 4-6 degrees. You should not resort to subjective methods of determining the temperature, but it is better to compare the readings when the air conditioner is on and off (turn off the air conditioner, do not turn off the fan).

Further, when the air conditioner is on, open the bonnet and make sure that there are no extraneous knocks, rattle, whistle, which indicate that it is necessary to replace some part. Engine speeds may rise slightly (up to 900–1000), on most Japanese cars, radiator fans turn on immediately, and the noise of a running compressor should be smooth and barely audible. Don’t be frightened by the lack of a clutch clutch, since on many modern cars (under 7 years old) it is not.

If the air conditioner does not work, then you should not listen to the seller’s comments, but rather reduce the price by R 5000 – R 8000 or consult with specialists about the cost of replacing or repairing it. Remember: before the sale, all minor faults are eliminated (refueling, replacing the compressor belt, replacing the cabin ventilation filter). The phrase: “I didn’t use it, most likely, you just need to refuel it”, most often there are serious problems, the elimination of which will have to spend a significant amount.

You can check the air conditioner for errors. Many modern cars are equipped with a climate control system integrated into a common diagnostic system, and full-format scanners see it. But if no errors were found, then it is still worth checking the expansion valve, filter drier, compressor and, if necessary, replace the elements. When buying a car in winter, you are unlikely to check the air conditioner. They begin to come for diagnostics only after the onset of warm spring days.