Repair and replacement of a car air conditioning compressor

Issues discussed in the material:

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

Various components and assemblies are responsible for the comfort of the driver and passengers in cars, which sometimes require replacement. A car air conditioner is one such component that deserves special attention, as it saves a person from the summer heat and makes the trip as comfortable as possible. This unit, like any other car part, requires periodic maintenance and repair. In this article we will look at situations when it is necessary to replace a car air conditioning compressor and how this happens.

Air conditioner design

You cannot repair the air conditioning compressor in a car yourself without knowing the principle of its structure. A car air conditioner is a complex design that includes:

• Compressor . The main part that ensures the flow of coolant to the radiator.
• Radiator . Promotes timely cooling of the refrigerant. Due to the fact that a car radiator is located near it, the air flow that occurs while the car is moving helps to further reduce the temperature.
• Fan. Cools the refrigerant to a certain temperature.
• Receiver. Responsible for filtering condensate from dirt and dust particles.
• Thermostatic valve. Through it, the condensate, which has turned into a gaseous state, is transported to the evaporation device.
• Evaporation device. Using a fan, it allows the cooled refrigerant to enter the car interior.

Another important part is the electric coupling. It is necessary so that after starting the car air conditioner, the pressure pulleys are tightly connected to the disk driven by the drive belt. When the electric coupling breaks, the car owner has to repair the air conditioning compressor.

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Antibacterial cleaning of the evaporator-conditioner

If you want the smell in the cabin to be pleasant when the air conditioner is operating, then it is necessary to systematically clean the evaporator. Do-it-yourself repair of the air conditioning compressor in this episode can and should be done. It is recommended to clean the air conditioner once every six months. We will need a spray cleaner for the car. Its contents are sprayed so that it falls on the evaporator.

At the same time, we activate the recirculation mode at maximum speed. This spray also forms a film on the evaporator. The goal is protection from external influences and prevention of the emergence of new microbes and pests. For high-quality operation of the air conditioner, it is recommended to turn it off a few minutes before arriving at your destination to dry the evaporator. This simple advice will help you operate your air conditioning compressor for a long time.

Features of the cooling system

Cooling the air inside a closed machine becomes possible in the following way. When a compressor, which has several special pistons, reduces the volume of refrigerant and converts it into liquid. The liquid spreads freely throughout the entire car air conditioning system and causes it to reduce the temperature in the cabin to the specified values. To avoid having to frequently repair the car air conditioning compressor, moving parts must be treated with a special lubricant.

Useful tips to increase compressor life

To avoid serious damage, it is enough to periodically perform diagnostics and everything will be fine. Here are the simplest recommendations that will extend the performance of your air conditioner:

• if the air conditioner is running, then the windows in the car must be closed;
• before turning on the air conditioner, the interior must be ventilated so that the air is not stale, since stale air has a bad effect on the operation of the air conditioner;
• every day it is advisable to look at the condition of the window at the receiver-dryer;
• It is advisable to periodically clean the interior from dust.

The compressor in a car air conditioner is considered the most expensive part, so if timely preventative maintenance is carried out and any breakdowns are corrected, the air conditioner will last a long time.

The following is a video on how to repair a car air conditioning compressor:

Principle of operation

The function of this unit is to compress, convert the refrigerant into a liquid state, and then circulate it in the system. Mostly in modern cars, piston compressors are used, where several pistons, driven by a “pumping washer” fixed to the supercharger shaft, moving in the axial direction, compress freon to the desired state and facilitate its further passage through the system.

Lubrication of the moving working parts of the compressor is provided by a special oil added to the refrigerant. For different brands of freon, the appropriate oil is added, mineral oil is added to the R12 brand, polyalkylene-glycol oil is added to R134a (PAG).

Compressor design features

Since the compressor is the main consumer of energy in the climate system, its tasks include the most labor-intensive part of the work - creating the required pressure in the system. In addition, according to the laws of thermodynamics, the molecules of a compressible gas heat up, and under the influence of pressure the gas turns into a liquid state. Strictly speaking, the possibility of changing the state of aggregation of the refrigerant is the fundamental principle that underlies this method of cooling warm air forced from the passenger compartment. Freon is a substance that, under the influence of pressure, easily becomes either a liquid or a gas, heating and cooling accordingly.

Insufficient lubrication of parts

Sometimes car enthusiasts use too little oil to lubricate elements or do it irregularly. In such cases, it will be necessary to overhaul the air conditioning compressor in the car. Otherwise, insufficient lubrication in the future will result in:

• Breakage of the bearing that occupies space in the constant rotation pulley. Strong heating of the bearing during operation leads to distortion of the pressure disk or burnout of the varnish on the electromagnetic clutch.
• Abrasion of the walls inside the case. As a result of strong friction of unlubricated parts, metal dust appears, which settles on rubber hoses, aluminum tubes, in the evaporator and other parts of the system, leading to jamming.

Sometimes low-quality lubricants containing large sediments are poured into the system. Then, during operation of the air conditioner, this sediment inevitably clogs the thermostatic valve and the receiver. To correct the situation, you will have to replace them with new ones, having first cleaned other parts of the air conditioning system.

The history of automobile air conditioning

The Americans were the first to realize the need to cool the car interior: on the long roads of hot states, the trip turned into a real test. Since the first air conditioners appeared at the beginning of the twentieth century (already in 1903 they were installed in the New York Stock Exchange building), and 30 years later they became a common interior detail, installing an air conditioning system in a car was only a matter of time.

Since 1933, air conditioners began to be installed in cars by order of the owners, and 1939 marked the beginning of a new stage: the installation of factory-installed air conditioning systems. Like all new products, it cost a lot of money and was only practical for the most expensive cars. But, like everything new, these first systems, despite their high cost, were ineffective and inconvenient. It was only in 1954 that air conditioning was combined with interior heating, increasing efficiency and making use much more convenient. In this version, the system has developed until the present day, gradually improving in detail, but not changing fundamentally.

Troubleshooting yourself

Once the cause of the malfunction has been determined, you can repair the car air conditioning compressors yourself. To do this, you will need to remove the refrigerant from the cooling system and open the compressor. The further algorithm of actions will depend on which part needs repair or replacement:

• Stuffing box . Dismantle the coupling hub, remove the locking element securing the gasket. In place of the old oil seal, install a new one using a special mandrel, and reassemble in the reverse order.
• Shaft bearing . Dismantle the electric coupling, remove the worn bearing, replace it with a new one.
• Electro coupling . Disassemble the supercharger. Remove the failed part - coil, shaft or pressure plate. Insert a new element and assemble the supercharger.
• Pump . In most cases, problems can be resolved by simply adding oil to the system. If the pump stops working due to large amounts of sediment or aluminum dust, the mechanism should be thoroughly flushed.

When the compressor housing has minor damage in the form of cracks, holes or chips, they can be easily repaired without dismantling the compressor. You just need to turn it off and seal the holes and cracks using argon-arc welding.

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Pulley removal

First you need to dismantle the air conditioning compressor

First you need to dismantle the air conditioning compressor. The following procedure is carried out:

1. Remove the instrument drive.
2. Disconnect the wiring from the control valve.
3. Unscrew the nuts.
4. Disconnect the handset. Remove 3 bolts from the compressor.

After this, remove the compressor.

Then clamp the coupling in a vice. Unscrew with a 7mm head and extension. The clutch should turn counterclockwise, and the key - vice versa. Remove the retaining ring and unscrew the coupling further. You will be able to remove the cover.

Then remove the retaining ring and pull the coupling.

Main unit of the climate system

Any air conditioner is essentially a refrigerator. And since both devices can be considered “close relatives,” then their internal structure is relatively the same and assumes that a car air conditioner has a compressor - a heart that accelerates the refrigerant through the system lines. Today, two types of compressors are mainly installed: piston and rotary vane.

Automotive air conditioning compressor

For the piston type, as the name suggests, the main part of the unit will be the piston. Such parts may be present inside the compressor in varying quantities - from one to several. This is where the way the engineering worked plays a role. The location of the pistons can also vary. They can be placed in a V-shape, crosswise and in one plane. The main thing is the ability to compress the coolant element in order to force it to circulate along the car air conditioner line from a high pressure zone (discharge area) to a low pressure zone (suction area).

The design of a rotary vane air conditioning compressor for a car is very similar to an electric pump for an air bed. When the rotor rotates, its blades create cavities that forcefully draw in the refrigerant on one side, and on the other, push it into the main line under pressure, forcing it to circulate through the evaporator pipes.

Design of a rotor-blade unit

The remaining types of automobile compressors number more than 40 modifications, and therefore we will not try to provide information in one article that is unlikely to be useful later. Let us only say that there is a variety of piston-type units with the scientific name “axial-piston superchargers”, which are based on a rotating inclined disk that forcibly pumps a coolant-forming mixture.

Video “Disassembling the compressor with your own hands”

Detailed instructions on how to independently disassemble a car air conditioning compressor in a garage are given in the video below (the author of the video is the Car Air Conditioning Repair channel).

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2022

Design and principle of operation

An air conditioner is a rather complex closed-loop system.

In order to understand how it works, it’s worth first considering each element separately:

• The compressor is the most complex element of the system. First of all, it is designed to compress the refrigerant and turn it into a high-temperature gas. The operation of the car air conditioning compressor is ensured by a belt through an electromagnetic clutch.
• A condenser - or, to put it more simply - an aluminum radiator of an air conditioner, it is inside it that the gas is converted into a liquid substance. As a rule, the radiator is equipped with electric fans that provide temperature regulation through airflow. Additionally, it is worth noting that the radiator is one of the most vulnerable parts of the entire system. It not only does not tolerate various types of mechanical stress well, but can also fail simply as a result of intensive use.
• Evaporator. It is an aluminum heat exchanger in which the refrigerant is converted from liquid to gaseous. The evaporator is located directly in the vehicle interior in the same place where the heater radiator is located.
• Expansion valve. A small but very important element, which directly determines how much refrigerant enters the evaporator and, therefore, the performance of the system as a whole will depend on this valve. To put it simply, this small valve is responsible for the temperature in the cabin.
• In some cases, instead of an expansion valve, an expansion tube can be used, which essentially performs the same task, but has a slightly different design. The use of an expansion valve or expansion tube depends solely on the design of the particular system.
• If an expansion tube is used in the car air conditioning system, the design will also contain a so-called accumulator-drier, which performs the function of drying and filtering the refrigerant.

The cost of replacing a car air conditioning compressor is approximately 3-5 thousand rubles

The car air conditioning system provides two ways to control the air temperature in the cabin:

• Manual control, in which the driver manually changes the air temperature in the cabin using special controls. At the same time, the process of operation of the air conditioner will be influenced by quite a lot of factors, such as the speed of the car, the ambient temperature, the speed at which the engine operates, etc.
• An automatic control system is considered more advanced. It is necessary to set the desired temperature in the control unit, and then the electronics itself will adapt to the driver’s requirements. To do this, the automatic system is equipped with several temperature sensors, an electronic control unit, as well as a number of rather complex dampers, valves, etc.

Antibiotic for infection, water for the radiator: how to service the air conditioner yourself?

Air conditioning (or even climate control) has long become an almost mandatory element of a car. And purely theoretically, we should have developed the habit of servicing it just as long ago. But this has not happened yet. It’s a little cold, and that’s okay. But it’s wrong. The air conditioner, like any other car system, requires attention. Otherwise, this insidious thing can take revenge on both the car owner and his car. The first one will sneeze, cough and suffer from the heat, and the second one will simply overheat. And I don’t know what’s scarier these days: coughing or overheating. Probably both are dangerous. Let's see how this can be avoided.

Very briefly about the operation of the air conditioner

We will not talk in detail about the physics of the air conditioner, but will limit ourselves to a brief story about the main components of the system. The task: to understand what and where can go wrong. To do this, there is no need to go into deep scientific jungle. So, what's in an air conditioner?

Let's start with the compressor. Usually it is of two types - axial piston or rotary vane, but if we decided to consider the system superficially, then we will not understand these terms. The main thing is that a compressor is needed to compress the freon and send it to the condenser (also known as a condenser, also known as an air conditioner radiator). Here freon passes from the gaseous phase into the liquid phase. When compressed by a compressor, the gas heats up, and the task of the condenser is to cool it so much that it turns into a liquid state.

From the condenser, freon goes to the dryer for filtration, then through the expansion valve (already in a gaseous state) to the evaporator. In it, warm air is cooled by cold freon, cools down and returns to the cabin through the deflectors. Well, the freon returns to the compressor to repeat its difficult cycle. The diagram is a little exaggerated (we skipped a bunch of electrics and didn’t say anything about transient processes in the condenser and expansion valve), but it allows us to generally imagine the operation of the air conditioning system. Of course, if there is climate control, the process is almost the same, so everything that we will talk about below applies to cars with a simple air conditioner and with “climate”.

So, what might require intervention here and what can you do on your own?

Compressor and condenser

The compressor is the most complex component of the system. And it sometimes breaks. Unfortunately, repairing or replacing a compressor is a difficult job, and it’s not easy to do anything yourself. True, now there are even kits for refilling the air conditioner yourself, but this does not change the essence of the matter. We will assume that we are lazy and clumsy, so we will leave all problems with the compressor to the car service center.

But with a condenser it’s a little more interesting. I have already said that this is the same radiator that usually stands first in the direction of travel of the car (sometimes there may be a small automatic transmission radiator in front of it if the car has an automatic transmission). On the one hand, this is good: the condenser covers the radiator of the cooling system from pebbles, sparrows and poplar fluff flying into it (the list goes on).

But one day there definitely comes a time when the condenser does not save the cooling system, but begins to greatly complicate its life. This moment comes when it is tightly clogged with the same poplar fluff, dust, dirt and sparrows. The radiators are in one package - close to each other. So close that the radiator package is often called a “sandwich”. And when the condenser becomes overgrown with dirt to the point of a monolithic brick, the temperature of the radiator of the cooling system also increases noticeably.

And to hell with the air conditioning, but when it is turned on, the engine begins to overheat. This is especially noticeable in traffic jams. When moving, the radiator is at least somehow able to be blown by the oncoming air flow, but in traffic jams it has a very hard time. By the way, if there is an automatic transmission radiator, then the temperature there will also rise, and this is very harmful for the transmission. In this case, the fans will thresh with all their power, but they will be of little use. As a result, the engine overheats, the transmission overheats, the fans roar, and the car slowly dies. What to do? Clean the condenser.

Yes, it's not that easy, but it's almost possible. I say “almost” because it is better to do this by disassembling the radiator package and washing them all, and not just the condenser. It’s more difficult to wash yourself, but if the situation is not too bad, it makes sense to suffer a little.

It is important to follow several rules. The first thing is not to try to break through a dirty radiator with a high-pressure washer by directing a stream of water at the poor fellow. Maybe you can wash something off, but most likely you can throw away the condenser after that - its honeycombs are soft and it’s easy to damage them.

Secondly, you need to wash it on both sides. And if it’s not so difficult to do this from the outside, then it’s almost impossible to get to the inside. People come up with different methods, making some kind of “watering cans” from drilled tubes that can be inserted into the gap between the engine radiator and the condenser. If you have a lot of free time and fantastic persistence, bordering on religious fanaticism, you can achieve good results. But an ordinary person can only cope with minor pollution.

Hence the conclusion: it is better to wash radiators preventively, and not after the temperature needle begins to hit the limiter at each traffic light. It is advisable to do this at least once every two years. In this case, you can usually do without disassembling the radiator package. It will be both cheaper and more useful for the car.

Sometimes it is recommended to blow out the condenser with compressed air. Well, it can be done. But air won't help with dirt. The maximum you can do is blow off the dust, so it’s better to wash it anyway. The main thing is to be careful. And you definitely shouldn’t scrub the condenser with a wire brush.

Nothing else good can be done with the condenser. Let's see where we can dig further.

Evaporator

As a matter of fact, cleaning the evaporator is what the services mean when they offer to clean the air conditioner. They, of course, use expensive professional equipment, but everything can be done simpler and cheaper.

There are two types of evaporator cleaner available in stores: aerosol and foam. The second method is for the lazy, the first is for the super lazy. That's where we'll start.

The purpose of the aerosol is to disinfect the air ducts and evaporator. To do this, she needs to get there. How to use a specific product correctly, you need to read the instructions. The general scheme of use is simple: spray inside the car, close all the windows, turn on the cabin circulation (that is, exclude the flow of outside air), turn on the air conditioner at full power for about 10 minutes. Then ventilate the car and enjoy life. Sometimes it is advised to spray an aerosol into the air intakes, which are usually located somewhere near the windshield. I don't know how effective this is. To be honest, the aerosol did not help me. I tried to use it to clean the air conditioner of an eight-year-old car, but it smelled like Dracula’s grave and continued to stink after treatment. A smoke bomb, which works on the same principle, helped me out. It is better to place it closer to the cabin filter. More precisely, to the place where it is installed, because it is better to remove the filter and install a new one after processing.

Some aerosol manufacturers claim that the filter does not need to be removed. They say that their product is so cool that it passes freely through the filter, killing all the microbes both in it and in the entire system. Maybe this is so, but it’s better to remove the filter, especially since this is usually not so difficult to do.

The second type of product is foam. It’s a little more difficult to work with, but it not only disinfects, but also cleans all air lines. It needs to be run into the evaporator drain hole or into the air duct behind the air filter. So you have to strain a little: either remove the filter, or crawl under the car in search of drainage.

You need to use foam carefully. It must settle completely in the system and, together with the dirt, flow out through the drainage. If you rush too much, foam may fly out of the air vents and into the cabin. And instead of a clean evaporator, there will be a pigsty in the cabin. In order not to accidentally ruin the entire enterprise, you need to read the instructions for use very carefully. There are no universal tips here - just follow the instructions.

There is nothing else to clean in the air conditioner. But something interesting still needs to be said.

Why might it work poorly?

There is an opinion among Russian motorists that the car air conditioning compressor is almost a prototype of a perpetual motion machine, and therefore does not require maintenance at all. We don’t like to read instructions and only remember them at the moment when almost the entire interior cooling system needs to be changed. Specifically, over time, the compressor suddenly begins to hum, and the design of the car air conditioner is such that it is not immediately clear where the hum comes from. The reasons may be different, but the first thing that comes to mind is a faulty pulley bearing or worn out belt drive. Such problems can be solved by the car enthusiast himself; replacement will not cause difficulties if you have the skills to communicate with hardware.

Worn belt drive

The situation may be much more serious if the piston is jammed inside the unit itself. There’s hardly anything that can be done about this, since the broken part probably damaged the valves and walls. If you are not too lazy, then the replacement will wait; it is not forbidden to try to repair the car air conditioning compressor. But, as practice shows, such measures lead only to temporary improvements and after some period the breakdown will recur. The best option for a car air conditioner in this case is a complete replacement of the compressor.

Car air conditioning compressor repair

More often than other breakdowns, seal failure occurs. This happens either due to damage to the oil seal, or due to loosening of the places where the main pipelines are attached to the device itself. In the case of the oil seal, the matter is complicated, because it needs to be replaced. If you have never had to press it out, it is better not to try. This requires a specialist and the availability of appropriate equipment. It is not difficult to eliminate looseness with your own hands.

Oil when refilling the air conditioner

There are two groups of oils for air conditioning systems - synthetic and mineral formulations. Determining exactly what is in your car air conditioner is not so difficult, but this matter requires some subtleties. All cars that were produced before 1994 run on R-12 freon. This type of freon is mixed with Suniso 5G mineral oil.

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Cars produced after 1994 run only on R-134a freon, which is used in combination with synthetic compounds PAG 46, PAG 100, PAG 150. These brands are also called polyalkylglycol. Oil for R-134a freon cannot be mineral, only synthetic. In practice, there are rare cases when in 1994 cars were produced with compressors for which both R-12 and R-134a freon could be used.

When installing a replacement car air conditioning compressor, it is very important to set it to the correct oil level, provided, of course, that the correct type and amount of oil is used.

First of all, you need to take into account the amount of oil in the replacement compressor. This could be a full fill (about 236 ml), a half fill, or no oil at all. If a replacement auto air conditioning compressor contains oil, it will need to be removed and refilled with the correct amount to balance the system.

In most cases, the filling process involves completely removing and measuring the amount of oil in the faulty compressor, and then filling the same amount of new oil into the replacement unit.

In addition, it is necessary to use the type and viscosity of oil recommended by the manufacturer. If, for example, a car air conditioning compressor requires a heavier oil, such as PAG 150 (polyalkylene glycol oil of viscosity type 150), and PAG 46 is used, the result will be noisy operation of the compressor and premature wear.

After filling the air conditioning compressor with oil, you should turn the compressor clutch manually or with a wrench at least 4 times before installing the unit itself. This is done for two reasons: spinning the clutch helps circulate oil throughout the compressor, which reduces the risk of compressor damage due to dry bearings, and it also reduces the starting torque when the clutch first moves.

Don't forget about the oil in the system

If you had to remove the car air conditioning compressor and repair it, then there is a possibility that you have upset the oil balance inside the system for its proper functioning. To prevent new problems associated with this cooling participant from appearing later, there are several recommendations from experienced motorists. When you dismantled the compressor, a certain amount of oil remained in the system, because not all of it had time to drain from the lines. First of all, if you have replaced the compressor, then these residues must be forcibly drained. All new units are already filled with oil in the required quantity.

To be on the safe side, measure the oil in the removed compressor and check the documentation for the volume in the new one. Then subtract the first number from the second number and remember the indicator. When draining the oil from the lines, make sure that the resulting value is equal to what you get from the air conditioner. If you get more, stop and let the excess remain in the system.

Draining oil from lines

If you were just making repairs and then put the device back in place, you will have to add oil. But the quantity is not taken from the ceiling, because an excess of this component in the system is fraught with jamming, after which only replacing the compressor will help you. When you have removed the device, drain the oil from it, measuring the volume. After the repair, you will have to fill the compressor with a new one (preferably) or the same one, and take 40 g more quantity. True, it is better to clarify this figure in the documentation for your device model. Oil should be filled through the high pressure port, otherwise there is a risk of not achieving the required evacuation inside the unit.

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How often should you recharge your car's air conditioner?

You should think about refilling freon if you have

• The air conditioner does not cool the air well
• Doesn't cool at all
• There is oil on the refrigerant pipes
• Or frost in the indoor unit

Auto air conditioners on new cars should be refilled once every 2-3 years.

For cars over 6 years old - every year.

What role does a compressor play in a car's air conditioning system?

The ventilation system in the car interior alone cannot 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 necessary to lower it. This task is performed by air conditioning systems.

Car air conditioning is valued by those who constantly use a car, because it creates coolness in the cabin in the sultry summer, and also warms up in the winter, warming up the cabin before the trip. Also, in addition to all its functions, the car air conditioner cleans the air. Its components constantly interact with heating and ventilation systems. The main function of a car air conditioner is to create a microclimate that is favorable for everyone inside 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-manifold, which serves to protect the compressor by evaporating the refrigerant. If there is no such addition, then there must be a hot space under the hood of the car. This ensures the required level of evaporation of the coolant in the return pipes, as well as in the evaporator.

A car air conditioner is a completely sealed system filled with refrigerant gas and compressor oil. Oil serves to lubricate all rubbing parts involved in work. This reduces wear on moving parts of the compressor and ensures sealing of gaps. In addition, oil removes some of the heat generated during friction of parts and removes small particles from equipment. During 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.

The joint work of all elements of the cooling system results in a favorable microclimate being created inside the car.

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“Diagnostics of a car air conditioner: restoring the usual comfort in the cabin” Read more

Conclusions and useful video on the topic

This video was filmed by specialists and may be useful to those who are eager to repair a split system compressor that has serious damage.

The operation of modern split systems shows quite long-term operation without the need for repairs. Moreover, if we are talking about serious defects, such as interturn short circuits or mechanical wear.

Simple faults can be repaired quite simply, and in the case of complex defects, replacing the split system with a new one seems like a reasonable solution. Serious repairs will force you to spend the same amount of money as purchasing a new split system requires.

Would you like to share compressor diagnostic methods that we did not talk about in this material? Write your comments, additions and recommendations in the block below.

If you are trying to independently figure out the reason for the breakdown of your split system and find yourself in a difficult situation, do not hesitate to ask for advice from our experts and other site visitors in the comments to this article.

Signs of trouble

The most common signs of malfunctions in the car air conditioning system are:

• Constant monotonous noise, and it can be heard even if the air conditioning is not working, but the engine is running. When the air conditioner is turned on, the nature of the hum changes in one direction or another. This sign indicates that it is time to replace the bearing on the compressor pulley.
• Another fairly common malfunction is a situation where, for some reason, the electromagnetic clutch does not turn on.
• Refrigerant leaks from the system, significantly reducing system efficiency.
• Extraneous noise when the air conditioner is running, in particular, we are talking about humming, knocking, characteristic “rumbling”, etc. In this case, quite significant pressure drops can be recorded in the system.

Replacing the coupling

The clutch is an essential element of a car air conditioner, providing a connection between the compressor shaft and the drive pulley, which rotates constantly, regardless of whether the climate system is on or inactive. Currently, several types of electromagnetic couplings are used, and each type requires the use of its own oil. If this requirement is not met, the coupling is guaranteed to fail much earlier than the mean time between failures. Since the clutch is connected to the pulley, it constantly rotates with it. When you turn on the car air conditioner, you hear a click, which indicates that it has engaged with the compressor shaft, thereby putting it into action.

If a click is not heard, and there is audible noise in the area of ​​the clutch, this is a clear sign that this compressor element is faulty. There are also situations when, according to all external symptoms, the coupling should be working, but the transmission of rotation from the engine to the compressor shaft does not occur. In such cases, diagnostics using special equipment helps to localize the cause of the malfunction. Note that such devices are quite expensive, so they are not found at every service station.

Note that due to the simplicity of the design, the drive coupling is considered a fairly durable unit that breaks relatively rarely. In any case, repairing a car's air conditioning compressor clutch is less profitable than replacing it, since it is inexpensive. And the replacement operation itself is quite simple (especially if you have already dismantled the compressor).

Possible causes of air conditioning compressor failure

• Compressor pulley bearing failure most often occurs due to simple wear. It is worth noting that this malfunction is very dangerous; if the bearing stops functioning correctly, there is a high probability that due to the increased load the electromagnetic coil will also fail. This also leads to pulley misalignment and possible refrigerant leakage.
• If the electromagnetic clutch does not work, then most likely it has simply failed due to overheating of the compressor. Also, on budget models, there may be a factory defect in the element. And, of course, we cannot exclude normal wear and tear associated with time and active use. The good news is that repairing this fault does not cause any big problems and can be done with fairly simple tools. In addition, the components in this case will be quite cheap.
• A leak in the car air conditioning system can be caused by damage to the housing parts or pipes. In the first case, it is highly not recommended to carry out repairs yourself; it would be more reasonable to turn to professionals who can repair the compressor. Well, replacing the connecting pipes of the air conditioner is much easier.
• The reason for the appearance of extraneous noise during operation of the air conditioner, as a rule, is the wear and tear of the working surfaces; pressure drops in the system are also explained by the failure of one or more valves responsible for the supply of refrigerant. The cause of failure is gradual wear of the system or a lack or excess of refrigerant. It is also worth checking the radiator for clogging, however, this is almost impossible to do at home.

Preventive inspection and replacement of the drive pulley bearing

If you hear a noise in the bowels of the car when operating the compressor, it means it’s time to inspect the bearing. Noises of unknown origin may also appear when the air conditioner is not working, when the shaft is idling. The car may hum due to a tightened drive belt, or due to complete wear of the air conditioning compressor bearing after its service life has expired.

The first step towards correcting this problem will be to check the main elements of this system, including inspecting the air conditioning compressor pulley. Carefully inspect the shaft drive belt. After stopping the engine, turn off the electromagnetic clutch, then turn the shaft. The hand force when turning should be noticeable. If the turn is tighter than usual, loosen the belt. In case of repeated failure, we replace the shaft bearing.

Repair of major faults

If any malfunctions are identified in the operation of the system, then, naturally, they will need to be eliminated as quickly as possible.

In some situations you can do this yourself:

• If any mechanical damage to the compressor housing is detected, it will be possible to eliminate them using a welding machine.
• When replacing the oil seal or gaskets, you will first need to remove the refrigerant from the system and remove the compressor from the vehicle.
• In order to replace the pulley bearing, you will also need to remove the compressor. Next, the bearing is removed and a new one is pressed in its place.
• Repair of an electromagnetic clutch involves replacing failed elements, in particular, a pressure plate, a burnt coil or pulley, it all depends on which part was subject to wear.
• It is quite difficult to eliminate malfunctions of the piston group with your own hands, since this will require completely disassembling the compressor. Therefore, the wise decision would be to seek the help of professionals.

Air conditioning in a car is a very convenient and practical thing. In order to ensure uninterrupted operation of the system, you should carefully monitor its performance and condition, because repairs are sometimes quite expensive.

Prevention

The best way to protect your car air conditioning compressor from breakdowns is to operate it correctly:

1. Close the car windows when he is working.
2. Regularly inspect the window in the receiver-dryer.
3. Do not neglect cleaning the interior, otherwise the accumulated dust will clog the air conditioner.

It is also worth paying close attention to malfunctions and malfunctions, and if they exist, immediately begin repairing the car air conditioning compressor.

Sometimes such a nuisance happens that the air conditioner may break down, this is especially unpleasant during hot weather. But by and large, this is not such a big problem; many people drive without air conditioning. But not in our case, because the air conditioner can be repaired quite simply. Moreover, all modern cars now have air conditioning. There are minor breakdowns, but there are also larger ones, for example, when the air conditioning compressor fails. Therefore, you will have to repair the car's air conditioning compressor. This situation can be solved, despite the fact that the compressor is considered the most important part in the air conditioner.

Diagnostics of the car air conditioning compressor

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

Often drivers, even with great experience, are mistaken, claiming that the compressor does not require attention and is the most reliable component of a car air conditioner. Such beliefs lead to the fact that it begins to work differently than before and some elements may need to be replaced. An example is the hum when the car air conditioner is turned on.

The sound of a running engine makes it difficult to determine the source of the noise. If the driver does not take any measures, this unit will soon become inoperative and may require expensive repairs or replacement of the car air conditioning compressor.

Malfunctions can manifest themselves both during an external inspection and by determining the characteristic noise during operation of the car air conditioner:

• Refrigerant leak - one of the reasons may be a leak through the oil seal or gasket at the connection points of the unit. Freon leaks are clearly visible under a UV lamp, but you must first add fluorescent paint to the refrigerant.
• Noise when the car air conditioner is operating, as well as when it is turned off, indicates that the shaft bearings or drive pulley need to be replaced. When such sounds occur, it is worth checking whether the belt is too tight. If, when the electromagnetic clutch is disconnected and the belt is loosened, the compressor pulley still spins tightly or jams manually, then the problem is in the bearing; if it rotates easily, then most likely the shaft bearing is humming.
• A malfunction of the electromagnetic clutch may be indicated by the absence of a click when turning on the air conditioner. The reason is the appearance of a large gap between the pressure plate and the pulley, which occurs due to wear-out of the clutch or in the event of the coil melting due to overheating of the compressor.
• A loud knocking or rumbling sound during operation indicates bent valves or worn-out working surfaces of the piston group. The discrepancy between the pressure measured at the inlet and outlet of the compressor and the nominal values ​​is also a sign of this defect.

In some cases, it may be necessary to completely replace the car air conditioning compressor. This need arises when the air conditioning system was installed incorrectly or the operating rules were not followed.

There is no point in rebuilding the car's air conditioning compressor in such cases. When there is a refrigerant leak, auto mechanics usually replace the filters, repair the leaks, and charge the system.

But most often, such a malfunction is eliminated in a more effective way, since depressurization of the system leads to moisture getting inside, which means it needs to be washed, and in some cases, disassembled and cleaned all components that have been exposed to aggressive dirt and moisture, as well as replacing the refrigerant .

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Checking the device depending on the defect

Let's consider the possible actions of a mechanic or split system user, taking into account all the faults noted above.

But first you should take note of the following points:

1. Such equipment is serviced by specialists. We talked about cleaning the split system yourself here.
2. The system is filled with chemically harmful substances.
3. The device operates from a high-potential network.
4. Electrical, electronic and mechanical knowledge is required.
5. There is a danger of harm to health.

A calm, reliable and qualified way to check the system is, of course, to turn to professional technicians.

However, the possibility of using personal skills and abilities at your own peril and risk is not excluded. For the second option, we will consider ways to check equipment for malfunctions.

Problem #1 - high level of mechanical noise

So, if a machine makes increased noise that is not typical for normal operation, we can state with high confidence that the internal components are destroyed.

These can be bearing units, valve group parts and others. In such cases, the only possible option is to replace the unit.

An attempt to repair a unit that has received internal damage. To access the internal contents, I had to cut the body with a cutting wheel. Meanwhile, after the repair you will have to seal the case hermetically

Increased noise can also be observed due to excess refrigerant charged into the system. However, in this case, the nature of the noise is clearly different from mechanical noise, and after a short period of operation, the compressor is usually turned off by the automatic system according to the high pressure parameter.

Checking for these two options is accompanied by the following actions:

1. Connect the pressure gauge station to the pressure side.
2. Close the system tap on the circuit line.
3. Monitor pressure readings.

With faulty valves, the noise level usually increases, but the pressure does not actually change or changes only slightly. If the bearings are faulty, an increase in noise will be accompanied by an increase in pressure.

Using a pressure gauge station to check the amount of refrigerant in the circuit pumped by the compressor. Often, due to a lack or excess of working substance, the operation of the unit is disrupted

An excessive amount of refrigerant in the circuit will also show an increase in pressure with an increase in noise and subsequent shutdown of the compressor by the automation system (pressure switch). We wrote more about the design of this unit, its operating principle, connection and adjustment in the next publication.

Problem #2 - overflow or lack of freon

A “fault” of this kind is determined, again using a pressure gauge station. It is necessary to disconnect the split system from the network, wait a little, then connect the pressure gauge station and start the air conditioner. Observe the readings on the instruments.

The operating pressure for a household split system of a specific configuration can always be determined by the technical tag (plate) attached to the body of the external module. There, on the plate, the boundary pressure parameters of the discharge and suction contour sections are indicated.

A plate with limit parameters indicating the limit values ​​of discharge and suction pressures. In case of troubleshooting, it is recommended to refer to this plate

If the table limits are exceeded, this indicates that the system is clearly overfilled with refrigerant. However, the table gives only upper pressure values.

Therefore, the lack of refrigerant is determined somewhat differently. The average suction pressure for household split systems is approximately 4-6 Bar (ATI), depending on the configuration.

When the pressure indicator of the suction part of the circuit at the pressure gauge station is significantly less than the specified range of 4-6 Bar, this factor indicates a lack of filling.

This condition also affects the operation of the compressor, with abnormal noise and intermittent activation of protective systems.

Problem #3 - refrigeration compressor does not start

A common compressor-related defect in split systems is the complete lack of starting time for the refrigeration compressor. In this case, the system successfully switches to cooling mode, all automation devices work normally. Another issue is the condenser fan.

The split system fan stops immediately when the air conditioner is turned on - this is a clear sign of failure of the starting capacitor, through which the compressor unit is supplied with current.

In this condition of the split system, the condenser fan shows somewhat unusual operation. When the air conditioner starts, the fan impeller begins to rotate, but almost immediately the rotation stops.

The indoor unit of the air conditioner continues to function when the compressor of the outdoor unit is not working.

This defect, as a rule, appears on systems that have successfully operated for several years (more than 5). And the reason for this behavior of the system is the starting capacitor connected to the power supply circuit of the compressor motor.

Diagnosing a faulty capacitor is easy. How to do this is below.

Problem #4 - turn-to-turn short circuit of the stator winding

How to determine such a malfunction is a far from ambiguous question. For example, when there is a short circuit of 2-3 turns in a short section, it is almost impossible to determine the defect without the use of a specific tool.

Damaged winding of the split system compressor. In this case, there is a break in individual conductors. This type of repair is only possible in a workshop, and even then not always with positive success.

Other variations, when sufficiently distant sections are closed to each other, can, in principle, be determined by simply measuring the resistance of the working windings of the motor stator.

Typically, the winding where there is a “short” winding gives less resistance relative to other windings. However, an accurate motor diagram will be required.

How much does it cost to replace a car air conditioning compressor?

Many foreign-made cars (Suzuki, Mitsubishi, Hуundai, Chevrolet, etc.) are equipped with complex systems. At a service station, auto mechanics can perform work to replace a car air conditioning compressor, the price of which will be about 3–5 thousand rubles or more, depending on the nature and complexity of the work performed.

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

What operations are included in replacing a car air conditioning compressor and are they necessary?

The main part of the repair work, as a rule, involves flushing the system, without which successful operation of the air conditioner is not guaranteed. At well-established car services, a similar procedure is performed for the reason that due to partial destruction, many mechanical particles enter the system, polluting it. Replacing a car air conditioning compressor with your own hands without flushing leads to the fact that the newly installed equipment quickly becomes unusable.

Dirt and oil, when mixed, create such a corrosive mixture that flushing the system becomes more difficult and must be done especially carefully.

In car services, special solvents and appropriate equipment are used for these purposes, so it is almost impossible to perform this operation yourself.

When replacing a car air conditioning compressor, the following mandatory work may also be performed to install equipment such as:

• receiver-dryer;
• The air conditioner radiator or, as it is also called, the condenser.

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

Before sending your car in for repairs, check with the car service center to see if refilling the system with refrigerant is included in the quoted price.

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How much does it cost to recharge the air conditioner in a car?

As a rule, refrigerant charging includes the following. The service includes:

• Refrigerant recovery
• Vacuum cleaning of the system from residual vapors
• Changing the oil in the compressor system
• Direct injection of freon
• Checking the air conditioning system after refueling

The issue price is usually from 500 UAH. or 1000 rub. which is about 20$

What else is being changed in the car air conditioner?

• Replacing the compressor pulley bearing

  
  

  
  Noise during operation, abrasions or other defects on the belt drive indicate that the bearing in the air conditioning compressor needs to be replaced. In both cases, a humming noise can be heard even when the air conditioning is turned off but the engine is running.

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

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

  It is possible that the pulley is misaligned, which leads to uneven wear and jamming of the compressor. It is also possible for the belt to break, which can severely damage the electrical wires. To prevent all of the above from happening, it is necessary to replace the faulty bearing as soon as possible.

• Replacing the air conditioning compressor oil seal
  The air conditioning compressor seal often needs to be replaced. It is located on the back side of the shaft and is subject to intense heat during operation. To replace it, you need to remove the compressor and drain the refrigerant. Using a puller, remove the coupling, pulley and magnet. We remove any remaining oil and dirt.

  Next you need to remove the retaining ring. We install the device for extracting the shaft on the shaft and, by moving the toe inward, we touch the shaft with the seal. We rotate the handle clockwise and remove the oil seal using an auxiliary device. We replace the car air conditioning compressor oil seal and install the part in its place.

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

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Repair of tubes and hoses

Timely diagnosis of connecting hoses coming from the compressor and exposed to high pressure is a guarantee of long-term operation of both the compressor and the entire climate system. If the recommended frequency of inspections is observed, the service life of a car air conditioning compressor can be increased by one and a half to two times. The problem is that main hoses are subject to shocks and vibrations that are inevitable when driving on imperfect roads. Another risk factor is the close proximity of the hoses going directly to the compressor to the exhaust manifold - a source of increased temperature. As a result, it is in these places that drying out and cracking of main pipelines most often occurs, which threatens the depressurization of the system.

The same result is possible with the aging of various rubber products - gaskets and sealing rings. Finally, loss of tightness is also possible on metal tubes that are susceptible to corrosion. Therefore, it is so important to regularly visually inspect the main pipelines (especially in the high-pressure section) and in all places where refrigerant leakage is possible. Oil stains will tell you that this is the case. In such cases, immediate repair of leaky elements (hoses, tubes, gaskets, o-rings) will be required, and if this is not possible, their complete replacement.

Price list for repair of car air conditioners 2020.

Types of equipment

The entire range of pumps for air conditioners can be divided into three main groups:

• Liquid.
• Separate.
• Peristaltic

Filling pumps are made in the form of a reservoir, tank or block. This type of drainage pump requires placement under the air conditioner pan (below its level), since it allows condensate to enter it by gravity. When the container is filled with condensate, the sensor is triggered and the pump turns on, and after pumping out the water it goes into sleep mode again.

However, bulk drainage pumps are quite large - to match their power and performance. Therefore, it is advisable to apply these models to powerful split systems or to a whole group of air conditioners.

The operating principles of bulk pumps involve the use of predominantly horizontal routes to drain water into the sewer system. And this is not always convenient.

Pumps of a separate design can even be installed directly in the drainage route - it all depends on the needs of the user. One of the advantages of this type of drainage pump is the ability to pump water out even from a two-meter distance from the innermost unit of the air conditioner.

In addition, this device is very suitable when it is necessary to drain condensate up the pipes. A separate drainage pump allows you to raise water to a height of about 15 meters.

Peristaltic models are quite specific and are intended for use in certain conditions - in the presence of a significant length of vertical sections of the route and elevation changes. The minimum pressure force of such models is 15 meters.

Classification of drainage equipment for split systems

There is a large amount of drainage equipment for various climate control equipment, which can be classified into 4 main groups:

1. Built-in. These are devices that are installed directly into the air conditioner housing, or more precisely, inside the condensate collection bath. They are used in duct and cassette split systems. The productivity of the device varies from 5 to 150 l/h.
2. Separate. The equipment of this group consists of a storage tank and a pump with a control unit, which are mounted in one housing. These two blocks are connected to each other by a flexible hose. A design feature of this device is the possibility of separate installation: the level sensor can be mounted directly into the internal module of the split system, and the pump is installed in the freon line box.
3. Liquid. Their design provides for a fairly large storage tank with a level sensor installed in it. The dimensions and performance of devices of this type are quite large, so they are ideal for high-power climate control equipment.
4. Peristaltic ones differ from the others in the ability to lift condensate through the drainage system to a height of more than 15 m with a fairly low productivity of up to 10 l/h.

Which air conditioner drainage is best to use?

As you can see, there are many types of hoses, each with its own pros and cons. Metal-plastic drainage and garden hose bends can bend, narrowing the hole for draining condensate. Thin-walled soft drainage (as well as various corrugations) can be damaged when pulled through the hole. Hard plastic drains are more attractive to insects. But a flexible specialized hose for air conditioning has more advantages than disadvantages. Because it does not compress when cornering and has a rigid protective braid that does not fray.

In conclusion, I want to say that the discussed disadvantages of hoses can be avoided. And if the installers’ arms grow out of their shoulders, then they will be able to install any air conditioner drain pipe most reliably! I recommend reading the article on choosing a water seal for drainage.