With the onset of summer heat, every driver dreams of saving coolness in the cabin, but often faces the fact that the climate system ceases to work effectively or emits unpleasant odors. One of the most common causes of failure of expensive components, such as a compressor or expansion-valveIt is pollution of internal highways by products of wear and oxidation of oil. It is in such situations that a special liquid for washing the air conditioning system comes to the rescue, capable of dissolving the sludge and restoring the circulation of the refrigerant.
Ignoring the need to clean the circuit can lead to the re-installation of the newly installed compressor, as microscopic particles of the metal will quickly disable it. Professional flush (from English) Flush - flushing - washing - was developed by chemists specifically for aggressive effects on pollution while fully preserving the integrity of rubber seals and aluminum alloys. In this article, we will discuss in detail what types of solvents exist, how to properly conduct the procedure and what can not be done in the maintenance process.
Why is it necessary to wash the contour of climate control
In the process of operating the car in the air conditioning system, complex physicochemical processes occur, which eventually lead to the degradation of working fluids. The main enemy of the sealed, seemingly contour is moisture, which penetrates through the micropores of hoses and causes the formation of acids that corrode the metal from the inside. The corrosion products are mixed with the waste oil to form an abrasive porridge that circulates through the system and acts as sandpaper for the rubbing compressor vapors.
If there is a serious breakdown, for example, jamming of the compressor or depressurization of the oil outlet line, washing becomes a mandatory procedure. Products of decay And metal shavings are distributed throughout the circuit, settling in hard-to-reach places, such as the evaporator and condenser. Without thorough cleaning, even replacing the compressor with a new one will not give a long-term result, since the remnants of dirt will quickly destroy the new unit.
⚠️ Warning: Attempting to start the system without first washing after a serious breakdown of the compressor is guaranteed to lead to instant failure of the new unit and loss of warranty on it.
In addition, regular maintenance using high-quality reagents allows you to extend the life of expensive components and maintain high efficiency of heat exchange. The contaminated capacitor (air conditioner radiator) gives off heat worse, which causes the system to work with increased load, increasing fuel consumption and engine wear.
Types of washing liquids and their composition
The automotive chemistry market offers many solutions for servicing climate systems, but not all of them are equally efficient and safe. The choice of a particular product depends on the type of contamination, the materials of the system and the recommendations of the car manufacturer. The main separation is based on the chemical basis of the solvent, which determines its aggressiveness and compatibility with the components.
The most common type is based on the hydrocarbon solvents. They have excellent dissolving power in relation to mineral and synthetic oils, as well as their oxidation products. Such liquids usually evaporate quickly, leaving no trace, which is critical for a system where foreign impurities are unacceptable.
- 🧪 Alcohol compounds Often used to remove moisture and light contaminants, safe for most rubber products, but may be less effective against thick sludge.
- 🛢️ Petroleum distillates - powerful solvents for heavy oily deposits, require extremely thorough drying of the system after application.
- 🌿 Biodegradables - environmentally friendly versions based on citrus or other plant components, less aggressive to metals, but have a longer drying time.
Separately, it is worth mentioning specialized formulations with anticorrosive additives, which not only clean, but also create a protective film on the inner walls. When choosing a tool, it is important to pay attention to the brand and certification, since the use of cheap analogues can lead to swelling of rubber seals or dissolution of plastic valve elements.
Can I use gasoline or acetone?
The use of pure gasoline, acetone or solvent 646 is strongly discouraged. These substances are too aggressive, can destroy rubber seals (O-ring), damage plastic elements of the expansion valve and leave a hard-to-remove oily plaque that will disrupt the system.
Instructions: step-by-step washing of the system with your own hands
The process of washing the air conditioning system requires accuracy, the presence of special equipment and compliance with safety precautions. Before starting work, it is necessary to make sure that the system is depressurized and the refrigerant is completely removed using special equipment for collecting freon, since direct release into the atmosphere is prohibited by law.
The first step is always to dismantle components that cannot be efficiently washed in the assembly or that may be damaged by the flushing fluid flow. First of all, the compressor, receiver dehumidifier and expansion valve (TRV) are removed, since these elements require replacement or separate cleaning, but are not washed under pressure in the circuit.
☑️ Preparation for flushing
Next, the procedure is as follows: connect a flushing gun or adapter to one of the highways (usually to the low pressure side) and apply the liquid under pressure of compressed nitrogen or carbon dioxide. The flow movement must be directed counterclockwise relative to the normal circulation of the refrigerant to wash away contaminants from the condenser and evaporator.
After the liquid passes through the radiators, repeat the procedure for each line separately until the outgoing solvent is completely transparent. Pay special attention blowing All elements with compressed air or nitrogen to completely remove the residues of the washing fluid, since even the slightest residual moisture or concentration can harm the new system.
⚠️ Warning: Never apply pressure washing fluid through a compressor, expansion valve or receiver dehumidifier – this will irrevocably damage these nodes.
Material compatibility and risk table
One of the key points when choosing chemistry is to understand what materials your air conditioning system is made of. Modern cars use complex aluminum alloys, different types of rubber (HNBR, EPDM) and plastics, each of which reacts differently to chemical reagents.
Incorrectly selected liquid can cause swelling of the sealing rings, which will lead to instant leakage of freon after refueling. There are also risks of corrosion of non-ferrous metals when using too aggressive acid or alkaline media not designed for automotive air conditioners.
| Type of component | fabrication | Risks of using aggressive solvents | Recommendation |
|---|---|---|---|
| O-rings | HNBR/NBR rubber | High (swelling, loss of elasticity) | Use only specialized flush liquids |
| Pipelines | coated aluminum | Medium (corrosion in the presence of moisture) | Thoroughly drying nitrogen after washing |
| Evaporator | Aluminum/Copper | Low (cell clogging) | Recurrent washing, neat purge |
| Plastic valves | thermoplastic | High (dissolution, deformation) | Dismantling before washing the circuit |
When working with systems that previously used oil type PAGIt is important to choose liquids that are guaranteed to mix with it and completely washed out. Residues of old oil mixed with washing can change the viscosity of the new oil, which will lead to insufficient lubrication of the compressor.
Typical errors in air conditioning maintenance
Even experienced craftsmen sometimes make mistakes that nullify all efforts to restore the system. One of the most common problems is insufficient time to dry the contour after washing. The remaining moisture inside will react with the refrigerant and oil, forming an aggressive acid, which in a few months will destroy the system from the inside.
Another common mistake is saving on the amount of washing fluid. Trying to save money, some try to wash the system "one portion", just driving dirt around. This is completely inefficient: the liquid must pass through the system once, carrying with it contaminants into the testing tank.
- 💧 Ignoring the replacement of the filter-dryer After any washing, this element must be replaced, as it absorbs moisture and dirt and is not regenerated in garage conditions.
- 🌬️ Blowing with mouth or compressor with oil Using a non-professional purge tool can introduce new dust, moisture or oil droplets from the compressor into the system.
- 🔄 Wrong flow direction Washing in the direction of normal operation of the system often cannot wash out contaminants from the thin channels of radiators.
It is also worth remembering that using the same container for different types of oils and washes without thoroughly washing it out can lead to a chemical reaction and the formation of a solid precipitate. Mixing of oils on polyalphaolefin (POE) and mineral basis is unacceptableThey can curl up into (the gel) and clog the system.
Final stage: Assembly and vacuuming
Once all the components of the system have been thoroughly washed and, most importantly, dried, the assembly phase begins. All dismantled elements are installed in place, new sealing rings are necessarily used, lubricated with special oil for air conditioners. Old rings cannot be used because they have lost their shape during the dismantling.
The next critical step is to vacuum the system. This process is necessary not only to create a dilution before refueling, but also to remove residual moisture that may have entered the system during assembly or remained after washing. The vacuum pump must operate for at least 30-40 minutes to vaporize water at low pressure.
Vacuum control: After the pump is turned off, close the valves and leave the system for 15-20 minutes. If the pressure gauge arrow began to crawl up, then the system remained leaky or moisture, and the vacuuming procedure must be repeated.
Only after successfully passing the test for tightness and vacuum resistance, you can start filling the system with oil and refrigerant. The amount of oil must strictly conform to the manufacturer’s specification, as some of the oil always remains in hard-to-reach areas of the system, and its excess is just as harmful as the lack.
⚠️ Note: It is forbidden to fill the system with refrigerant if the vacuum is not maintained. The presence of air in the system will lead to an increase in pressure, overloading of the compressor and possible explosion of the elements.
Questions and Answers (FAQ)
Can I wash the air conditioning system without removing it from the car?
It is impossible to fully wash the system without removing the main units. The compressor, receiver-dryer and expansion valve must be dismantled. Only the pipelines, condenser and evaporator that remain on the car or are removed separately for easy access are washed.
How much liquid is needed for a high-quality washing?
Volume depends on the degree of contamination and the size of the system, but typically requires 0.5 to 1 litre of specialized fluid per circuit (high and low pressure side). The main criterion is the purity of the outgoing solution, it should become transparent.
What is dangerous getting wash fluid into the compressor?
The washing liquid does not have the lubricating properties of oil. If it hits the compressor at start-up, dry friction will occur, resulting in instantaneous friction vapor scoop and compressor wedge. That is why the compressor is always removed before washing the contour.
Should I change the oil in the compressor after washing the system?
Yes, if you change the compressor, the new one already has oil. If you leave the old (with preventive washing), you need to drain the old oil, wash the crankcase (if possible) and pour fresh oil strictly of the viscosity and type specified by the manufacturer (PAG, POE or mineral).