How to properly refill a car air conditioner with your own hands?

Many car owners are interested in when to refill the air conditioning in their car? The answer to this question is quite simple. If there is still little freon – it’s time to refill the car air conditioner. To save extra money, you can do it yourself.

But how exactly do you refill the air conditioner yourself? What tools will be needed for this? And what rules should you remember? These issues will be discussed below.

Purpose and advantage

A car air conditioner is an indispensable assistant in the summer, when the temperature outside the window exceeds 30 degrees.

The wide-open windows and sunroof in the car only play the role of a fan and simply drive hot air around the cabin.

In turn, the climate system works on a different principle and performs a number of useful functions:

• reduces the air temperature to the temperature required by the car enthusiast;
• effectively combats “sweating” of glass (this can be useful in winter);
• maintains humidity levels at optimal levels;
• reliably protects the car interior from the ingress of unpleasant odors and burnt gasoline vapors;
• is a very powerful filter for air inside the cabin;
• you don’t need to open the windows - the cooling and cleaning system will do everything itself.

Car air conditioning is an option that is never superfluous. If desired, the device can be installed in almost any car (even if it is not included in your configuration).

How much does it cost to refill a car air conditioner?

If there is not enough freon in the system and the air conditioner does not cool the interior well, then there are 2 options: refill it yourself or contact a service station. If you go to a car service center, they charge an average of 1,500 rubles for a full refill of a car air conditioner. Some drivers do not fully charge the system, but simply add freon. This costs on average 300 rubles per 100 grams. Specialists measure how much freon is missing in the system and add it until the required pressure is reached. That is, if the system does not have enough freon 150 grams, then refilling will cost only 450 rubles.

At some service stations the prices are lower, at others – higher. However, everyone decides for themselves where to refill the car air conditioner. But this can be done at many service stations.

Principle of operation

A car air conditioner consists of several elements:

1. A compressor that ensures constant circulation of freon throughout the cooling system circuit;
2. Condenser - heat exchanger. In this unit, freon vapor accumulates and condenses with further heat release;
3. An evaporator acting as a heat exchanger. It is in it that the evaporation of liquid freon and the removal of heat occurs;
4. Receiver-dryer, through which the refrigerant is cleaned and dried;
5. Pipelines;
6. Expansion valve;
7. Cooling fan;
8. Automation systems (fuses, sensors, etc.).

Essentially, a car air conditioner has three main elements - a compressor, an evaporator and a condenser. All other details play a supporting role.

The system works according to the following principle.

Freon is in a closed circuit. Under the action of the compressor, the refrigerant is heated and sent further through the system under pressure.

On its way there is a condenser, where the refrigerant is cooled and converted into liquefied gas.

After this, the freon enters the receiver-dryer, which filters out dirt and debris.

The refrigerant then passes through numerous pipes in the system and flows to the expansion valve.

After cooling, the freon is sent to the evaporator (located directly inside the car) and enters the passenger compartment. The refrigerant is then sent to the compressor.

That's it - the cycle is closed. By the way, in addition to its cooling function, the evaporator also effectively dehumidifies the air.

Procedure for filling car air conditioners with refrigerant

To refill car air conditioners on most modern cars, R-134a (tetrafluoroethane) refrigerant is used, but in the old fashioned way everyone calls it freon. To refill the air conditioning system of a small or medium-class passenger car, you will need an average of about 0.5 kg of refrigerant.

You can find out information about the type of refrigerant for your car’s air conditioner and its refill rate from the service book for the car. Also, this information is often indicated on a plate located on the inside of the hood.

Refilling car air conditioners with refrigerant consists of the following steps:

1. Pumping out remaining refrigerant from the air conditioning system. Modern stations for refilling car air conditioners automatically pump out old refrigerant to weigh it and remove waste oil from it.
2. Evacuation of the system. This is a very important stage in recharging the car air conditioner. As a result of this operation, residual air and moisture are removed from the system. To achieve a vacuum of the required depth, it may take from 10 to 30 minutes (depending on the power and class of equipment); it is impossible to perform high-quality vacuuming in 1-2 minutes.
3. The leak test allows you to detect any leaks present in the system. If the evacuation is poor (stage No. 2), the leak test may not show existing leaks, which will lead to further malfunctions of the car air conditioner.
4. Refilling the oil. During the operation of the car air conditioner, the oil filled into the system (on average about 15 grams) serves to lubricate the compressor mechanisms. Quite often, the oil is filled with a dye (tracer) to make it easier to identify possible leaks in the future.
5. Refrigerant loading. This is the final stage of refueling car air conditioners, which takes place quite quickly. As we already wrote above, on average, about 500 grams of refrigerant are needed to refill one air conditioner in a passenger car.

After completing all stages of refueling, you need to start the car engine, turn on the air conditioning (blowing at full power), increase the engine speed to 2500-3000 rpm, after which you need to carefully observe the operation of the system:

• The pressure in the low and high pressure ports should return to normal immediately after turning on the car air conditioning compressor. The low pressure gauge should show about 2 bar, and the high pressure gauge should show 15-18 bar.
• Check the temperature of the low pressure circuit tube by touch with your hand - it should be cold.
• Cold air should come out of the deflectors in the car's interior, and the air conditioning compressor should periodically turn off.

The presence of all these signs indicates that the air conditioner in the car has been charged successfully and the driver can enjoy its proper operation.

As you understand, it will be practically impossible to refill a car air conditioner with high quality without professional equipment. However, you can assemble a kit for refilling car air conditioners yourself from available and inexpensive components yourself. At the end of this article, watch a video on how to use this set.

And for a general idea of ​​the cost of this type of service, below we present the order of prices for refilling car air conditioners in large cities of Russia (Moscow, St. Petersburg, Volgograd, Nizhny Novgorod, Krasnodar, etc.).

The main reasons for refueling

Many car enthusiasts do not know when to refill their car air conditioner and remember this only when the device fails. But here it is important to consider several options.

Natural leak.

Freon is in a closed circuit, but even this does not save it from a small leak. It is believed that up to 10-15% of the refrigerant leaves the system over the course of a year.

Consequently, most modern cars require refueling after three years, and older models even earlier - after 1-2 years.

System malfunction.

If the refrigerant leak exceeds 15-20% per year, then we can safely say that the system is faulty.

The reasons may be the following:

• leakage in pipeline systems due to increased vibration (for example, reduced efficiency of gaskets);
• presence of mechanical damage (holes, cracks) on pipes or main components of the system;
• the appearance of corrosion directly in the capacitor itself (this phenomenon occurs very often).

Equipment and tools for refueling

To refill your car air conditioner with your own hands, you will need: a station for measuring pressure, an adapter with a tap, two hoses and a cylinder of freon.

From these components you need to assemble a device for refilling the air conditioning system.

The procedure should be as follows:

1. Take a freon bottle and screw an adapter with a tap onto it (there should be a thread on the top of the bottle);
2. Connect the hose to the adapter;
3. Attach the hose to the pressure measuring station;
4. Attach another hose with an adapter to the pressure control station on the other side;
5. The filling device is ready. Please note that some stores sell already assembled devices.

Also, in some cases, you may need additional equipment - if you are doing evacuation, then you will need a vacuum pump , if you are checking the integrity of pipes with pressure, then in this case you will have to buy a cylinder with safe gas , and so on.

Freon selection

To charge the air conditioner, use R134a cooling mixture .

Older installations ran on R12 freon, but in the nineties this mixture was banned due to its negative impact on the environment, and after the ban, the R134a mixture began to be used in air conditioners. To refill a car air conditioner, about 700-1000 g of mixture is required.

Leak detection methods

Today there are several main ways to quickly find a leak in a car air conditioner.

Let's look at the most popular of them.

Using a leak detector.

Such a modern device provides real assistance in finding a leak when it is not possible to visually find the problem.

The advantage of the product is high sensitivity and accuracy. But the leak detector has a drawback. If the damage is small, then it will not be possible to find it this way.

Nitrogen filling.

This technique is as old as the world, but is still actively used today to check car air conditioning. Its essence comes down to filling the system with nitrogen under high pressure.

In this case, the location of the freon leak is determined solely by ear. The advantage of this method is simplicity and accessibility. Disadvantage: low efficiency.

Soap solution.

To simplify the search process, a soap solution is often used. But it's dangerous. The air conditioning system contains not only freon, but also oil to lubricate the compressor.

The latter is capable of absorbing moisture well and can only be combined with a specific type of freon.

The use of a soap composition often leads to compressor breakdown and, as a result, serious waste.

Application of ultraviolet additive.

Modern and most effective method for leak detection. It is actively used by employees of almost all modern service stations. The point is simple.

In the process of filling the car air conditioner with freon, a little special additive is added to the composition.

The latter mixes with the contents of the system (refrigerant, oil) and when released outside (at the leak) becomes green.

The advantage of this method is clarity (the location of damage in the system is immediately visible) and absolute safety for the system. The downside is the high cost.

How to understand when it's time to recharge your air conditioner

Another name for a capacitor is a radiator, and this part of the car is periodically cleaned of dust and dirt, which helps avoid corrosion.

Even in good condition, the car's air conditioning system gradually loses refrigerant (freon). According to regulations, a loss of 15% freon in one year is considered normal. According to technical conditions, a leak of 50% of the refrigerant or more leads to the fact that the car air conditioner is no longer able to work effectively. Therefore, even a properly functioning system must be recharged with refrigerant every 3 years.

However, in older cars the situation is different. Freon loss can occur much faster and in larger volumes. Therefore, on such cars, the car air conditioner needs to be refilled much more often.

It’s quite easy to sense that your air conditioner needs to be recharged. If it can no longer cope with the high temperature in the cabin on summer days, you need to go to a service center or change the refrigerant in it yourself.

You will also have to refill the air conditioner if the air conditioning system is depressurized due to a breakdown. In this case, before refueling, it is necessary to eliminate the cause of the leak, which usually lies in mechanical damage to the tubes or corrosion of the air conditioner condenser. In the first case, you need to seal the leaks with sealant; in the second, most likely, you will have to replace the capacitor itself.

Repairing the leak

If the damage is significant or an entire system unit has failed, then it is better to contact professionals for repairs.

But most often the damage to the air conditioner is minor. Therefore, you can carry out restoration work yourself.

There are two options here.

Using a special patch.

Here the sequence is as follows:

• prepare a small metal tube that fits the diameter;
• place small clamps on it, clean it with sandpaper and degrease it with an alcohol solution;
• connect the two halves of the coupling using regular electrical tape;
• Apply glue to the prepared coupling, place the part in place and tighten it with clamps.

As an option.

Using sealant.

Today, special products are sold that effectively heal minor damage. All that is necessary is to pump them into the system along with freon.

After 20-30 minutes, the existing cracks will disappear, and the problem with freon leakage from the car air conditioner will be eliminated.

Air conditioner care

Now you know how to charge the air conditioner in a car with your own hands. In conclusion, let's talk about the rules of care :

• Wash the radiator at least once every 3 months, as dirt and dust constantly settle on it, which significantly reduces the efficiency of the device.
• In winter, you need to warm up the air conditioner at least once a month. To warm up, you need to drive the car into a warm place and turn on the cooling device for 15-30 minutes.

If leaks occur, contact a service center for repairs or repair the pipes yourself.

Watch the video yourself to see how to recharge the air conditioner in your car.

Preparatory work

Before refilling your car air conditioner, you must clearly determine the required type and volume of refrigerant. Everything is simple here.

If your car was manufactured before 1992, then you should use the R-12 type of freon.

Since 1993, car manufacturers have been pumping in R-134a freon. The reason is a banal ban on the use of R-12.

Difficulties may arise only for owners of cars produced in 1992-1993, because during the transition period, not all manufacturers immediately switched to R-134a.

To find out more accurate information, carefully study the sticker on the inside of the hood (this data is usually indicated there).

The second option is that you can recognize the type of freon by the fitting. In new models of car air conditioners that operate on R-134a, the fitting has a larger height and diameter.

As for the refrigerant charging standards, they are indicated on the plate that we talked about above.

In addition, this information can be obtained from a specialist or in the operating instructions.

On average, the norm for domestic cars is about 500-1000 grams.

How often to recharge the air conditioner in your car

As already mentioned, you need to refill your air conditioner at least once every three years. But such regulations are valid only for new cars. If the car is more than 6 years old, then the car air conditioner should be checked and refilled annually, and even more often in the case where air conditioning system leaks are not eliminated.

Refilling the air conditioner yourself is quite simple. A basic kit for this work costs about 1 thousand rubles - in fact, this is slightly less than the price of one gas station at the service station. Therefore, motorists are not always willing or able to carry out such a procedure. However, for those who are accustomed to complete control of their “iron horse” and repairing it themselves, refueling with their own hands looks like a worthy alternative to a trip to a service station.

• Author: Exudha
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Final check and troubleshooting

Now all that remains is to turn on the car air conditioner and check its operation. Here pay attention to the following points:

• make sure that within a few seconds after turning on the air conditioner, cold air begins to flow into the cabin;
• inspect the entire system for freon leaks;
• if you suspect a leak, you can re-check (we discussed the technology above);
• listen to the operation of the compressor; if there are extraneous noises, this may indicate wear of parts or internal damage to the unit. Often the cause of noise is a faulty bearing, as a result this can lead to failure and repair of the compressor;
• Clean air should come out of the system, without any unnecessary odor. Otherwise, replace the cabin filter.

Freon selection

A professional service station with qualified personnel can be used to recharge the car's air conditioner. Although many drivers want to maintain their car themselves. Solving such problems may require different types of tools. But in all cases it is necessary to purchase the refrigerant itself. Previously, all cars used R12 freon refill. This composition contained fluorine and was very productive. Efficiency indicators are even higher than modern solutions. The only problem with R12 is the fact of the increased harmfulness of the refrigerant. Due to the identified problems that the composition leads to, in 1992 it was decided to completely abandon its use. R12 was officially banned.

All motorists who own vehicles manufactured in 1992 have switched to the new R134a composition. And owners of old cars were forced to buy and refill the old mixture themselves, or switch to an updated type of freon. All gas stations were officially ordered to completely eliminate freon containing chlorine and fluorine.

When selecting the composition for each specific air conditioning system on your car, you can simply lift the hood and look at the appropriate plate. It indicates what refrigerant is used here. But it is difficult to confuse the systems, since the filling fittings used, in addition to other differences, are completely different. Thus, on the new type of refrigerant pipes, the fitting was higher and had a larger diameter. There are stickers in the engine compartment of cars indicating the type and rate of refilling of the car air conditioner.

Required quantity

Also, motorists do not always understand exactly how much refrigerant they need to refill the air conditioner. After all, it doesn’t make sense to buy an excessive amount, since you will spend extra money and not use the freon itself. The pleasure is not the cheapest, so it is recommended to first accurately calculate the required filling volume. In the best case, the car has a special plate under the hood indicating the type, norm and required amount of the substance. But not everyone is so lucky, since some cars do not have a plate for one reason or another.

If there are no recommendations from the manufacturer under the hood, you should seek help from an authorized dealer or the machine’s operating manual. Such information is necessarily duplicated there. For Russian cars, the norm for most refilled air conditioners is considered to be from 600 to 900 grams. Although sometimes absolute accuracy does not play a big role, since refueling and partial filling of the air conditioning system with refrigerant are carried out independently. The air conditioner can be filled with freon:

• at a factory during the production of a car;
• after renovation;
• as part of scheduled maintenance, etc.

https://www.youtube.com/watch?v=wCsNxUKktTU

After repairs and at the factory, when the system is empty, it is fully charged. But as part of scheduled maintenance, only refueling is carried out, which is why it is only possible to fill the air conditioner to normal. Only in this state will the unit be able to operate at full capacity. Partial refilling is problematic because we cannot know exactly how much freon is left inside the system. For this reason, refueling is carried out by monitoring the pressure on the pressure gauge. So if you were unable to find out the exact numbers and determine the amount of refrigerant required, then just start from the arrow of the measuring device.

Using oil when refueling

If you look carefully at the table for the amount of refrigerant in the air conditioning unit, you will see the value and oil standards there. At the same time, not everyone knows the nuances of refilling it and the reasons for its use. Some car owners, when filling the air conditioner in their car with their own hands, always recommend adding oil. But in fact, if there is an excess amount of lubricant, breakdowns of the piston compressor occur. This is due to the fact that when oil passes through the unit along with the refrigerant, carbon deposits appear on the components. And it’s not entirely clear how to act in such a situation.

But experts give simple and clear advice. When refilling the air conditioner in a car, use freon, which already contains a certain amount of oil. The manufacturer indicates the relevant information on the packaging of the can. Everything there is strictly dosed, so you can’t overdo it with oil or add too little. Be sure to read the owner's manual specific to your car. The thing is that some cars require separate refilling of freon and oil. Then so-called polyalkylene glycol oils, abbreviated PAG, are used. In this case, oil will need to be poured into the compressor using the appropriate inlet in the crankcase.

Vacuuming

In addition to the procedure for refilling freon and pouring oil into the system, many people overlook such a significant operation as vacuumization or evacuation of the air conditioner. It is almost impossible to avoid the penetration of air and moisture into the car air conditioning system if less than 50% freon remains inside it. Yes, the equipment will continue to operate, although it will not be able to operate at full capacity. The probability of compressor failure and the formation of rust (corrosion) on the tubes of the unit is too high. If you miss this point, expensive repairs will be required. It will cost significantly more than conventional vacuuming. To remove accumulated air and moisture from the system, you will need to use a vacuum pump.

To vacuum the air conditioner yourself, you need to follow a certain sequence of procedures and actions:

1. Turn on the car heater and warm up the car. This will allow moisture to condense in the evaporator.
2. Connect a vacuum pump to the compressor connection. Now unscrew the nipple and turn the tap under it. You need to turn it counterclockwise.
3. Turn on the pump. Let it run for 15 minutes. When the required time has passed, tighten the valves and turn off the pump.
4. Step by step this procedure should be repeated several times.

When you finish vacuuming, be sure to wait a few hours. There is no need to wait more than 4 hours. Only after this is it possible to start refilling the car air conditioner.

Simple diagram of a car air conditioner

Currently, there are a lot of types of control of car air conditioning, which are based on all sorts of sensors - interior temperature sensor, outdoor temperature sensor, etc.

Such devices are called AK with climate control.

There are a lot of AK circuits, but I decided to present what I think is the simplest circuit for turning on an air conditioning compressor and show how the cooling fan turns on.

Let's look at the diagram:

I present the simplest air conditioner circuit for a car. The operating principle of the device is presented below.

When the car’s ignition is turned on, 12 volts appears on two fuses (1-15 Ampere, 11-20 Ampere), and so we start the car. And now there are already 14 Volts on these fuses.

To start the car fan system, simply turn on the interior heater fan with button 2. After turning on the fan, on the air conditioner button, i.e.

e 3, 14 volts appears, press this button and the voltage reaches the emergency pressure sensor - button 4.

If the pressure in the air conditioner exceeds 18 bar, the emergency pressure sensor will close the circuit and the air conditioner will turn off, since the voltage will not reach it.

By this we will save the system, since the pressure will not increase. If the same emergency pressure sensor (4) is closed, the voltage reaches the low pressure sensor (number 5 in the circuit), which in turn closes the circuit if the pressure in the Auto air conditioning system exceeds 2bar.

The sensor may open if there are problems with the operation of the sensor, or if there is not enough pressure in the system to turn it on.

If everything is in order, power comes to control the relay for turning on the compressor electromagnet (in diagram-6), after the relay is triggered, from the 20 Ampere fuse (11) power goes to the compressor electromagnet (in diagram-7).

Now let's look at the high pressure sensor (in diagram 8). Such a sensor is needed to avoid troubles from excess pressure in the A.K. system. This sensor turns on if the pressure in the system exceeds 15 bar.

As soon as the sensor turns on, power from the first 15 Amp fuse goes to the cooling fan relay (in diagram 9). The relay closes the wire that goes from another 20 Ampere fuse (11) to the additional cooling fan (10 in the diagram).

This is exactly how the simplest circuit for turning on a car air conditioning system works.

Now let's look at the circuit with clomat control. In such circuits, special interior and exterior temperature sensors are installed. The sensors work like this: if the ambient temperature is below 5 degrees Celsius, the fan turns off.

But the air conditioner must be turned on twice a month in winter, and let it be only 15-20 minutes.

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Therefore, owners of cars with such a control system have to look for a warm place for their car, or use a hairdryer to warm the ambient temperature sensor; such sensors are mainly installed in front, between the front radiator and the bumper.

On Mercedes cars there are relays that separately control valves that shut off the supply of hot antifreeze to the heater radiator, or mix it in to maintain the temperature in the cabin that you set in advance. On some cars, the climate simply turns off and turns on the air conditioning compressor, on others the climate simply opens the dampers slightly and mixes in hot air to maintain the temperature.

Pressure sensors are also different, for example, on Renault cars there are often sensors with three terminals that do not close the wire as shown in the diagram above, but change their resistance depending on the change in pressure in the air conditioning system.

On Peugeot cars, the air conditioning radiator cooling fan turns on immediately, along with the compressor; they have two speeds. When the pressure rises to critical, the fan spins faster.

On some Mercedes and BMW models, there were high pressure sensors, which, depending on the pressure, changed resistance, and the cooling fan, depending on the resistance of the sensor, gained momentum (the Germans are great, they came up with an interesting idea, but these fans are not reliable and their price is not small, for example BMW X5 - the fan cost 500 USD in 2008).

Compressors are also turned on in different ways, some are turned on using an electromagnet, others are turned on using an electric valve, which is installed directly inside the compressor (the insides of such compressors rotate constantly).

If you bought yourself a new car with air conditioning, you should turn it on and check it. And so the clutch on the compressor engages and the compressor starts to rotate, but you don’t feel cold, which means it’s not fixed! Turn off the devices and head to an AK repair specialist.