How to repair a car air conditioner pipe with your own hands
Content
Freon is used as a refrigerant in the automotive air conditioning system, which has a high fluidity and is able to penetrate through the slightest damage. The loss of even a small fraction of the total amount sharply reduces the efficiency of air cooling in the cabin.
If the defect consists in the appearance of a crack or a small hole in the main pipe, then the gas leaves completely, and together with the lubricating oil.
Why air conditioner pipes start to fail
Modern tubes are made of thin-walled aluminum and do not have a margin of safety.
There can be several reasons for the formation of leaks:
- external and internal corrosion, aluminum and alloys based on it are constantly protected by an oxide layer, but if it is violated by chemical or mechanical means, the metal quickly reacts with many substances and is destroyed;
- vibration loads, some light alloys are brittle during aging and are easily covered with a network of microcracks;
- mechanical damage during an accident, inaccurate repair interventions or improper laying without protection from external influences;
- tubes are quickly wiped when their fastening is destroyed and surrounding parts are touched.
Usually, damages are poorly distinguished visually, they have to be searched for by indirect signs or leak diagnostic methods.
How to identify tube damage
Sometimes, when examining the highways, you can notice traces of oil drips, which is part of the freon when refueling. But it also tends to evaporate over time or be masked by external dirt.
To accurately determine the location of damage, the engine compartment is washed, after which the system is pressed using a special dye, which is clearly visible in the light of an ultraviolet lamp.
It can also be added to the composition of the refrigerant to determine traces of slow leakage during operation.
Repair methods
The best and most radical repair method would be to replace the affected tube with a new original part. This is not very cheap, but reliable, such a spare part has a resource comparable to a conveyor assembly, and with a high probability it will not cause trouble until the end of the car's service life.
When buying a part, you need to immediately select O-rings made of metal with a layer of rubber applied by catalog numbers, they are disposable.
But it is not always possible to quickly get the right spare part. Especially on old, rare cars. Few people want to wait for the end of the delivery time in the season. Therefore, repair technologies of varying degrees of reliability can be applied.
Argon arc welding
Cooking aluminum and its alloys is not easy, precisely because of the rapid formation of the same oxide film on its surface. The metal instantly reacts with oxygen, which is always present in the surrounding atmosphere. Especially at high temperatures, which require soldering or welding processes.
Aluminum welding is carried out by specialized devices in an argon environment. In this case, the access of oxygen to the seam is excluded by a continuous flow of inert gas, and the filling of defects is ensured by the supply of filler material supplied in the form of rods of various chemical composition.
Working with argon devices is hardly possible on your own, the equipment is very expensive, and the process itself requires a lot of experience and qualifications.
It is much easier to remove the damaged tube and use the services of a professional welder. If the damage is single, but in general the tube is well preserved, then the part repaired in this way will serve no worse than a new one.
Repair compounds
For quick repairs, you can use epoxy compositions such as "cold welding" and reinforcing bandages. This method does not differ in reliability and will not last long, this can be considered only a temporary measure. But sometimes it is possible to obtain a sufficiently strong and tight connection.
In any case, the tube will have to be removed and thoroughly cleaned from traces of dirt, grease and oxides. To give strength to the patch, reinforcement with fabric materials, for example, based on fiberglass, is used.
A fiberglass bandage is formed, the tightness of which is determined by the quality of cleaning and adhesion of the compound to the metal surface. For better contact, the hole or crack is cut mechanically.
Ready-made kits
Sometimes it is more expedient to replace the metal tube with a rubber hose with tips, or make it yourself. There are kits for this kind of work. They include tubes, fittings, a crimping tool.
If flexible hoses are used, then the material must be special, these are reinforced rubber hoses with resistance to freon, oil, high and low temperatures, and also able to withstand the pressure in the line with a margin.
Popular compositions for repairing the air conditioning tube
Several compositions can be distinguished, depending on the repair technology.
Solder repair
Uses a propane gas torch and Castolin aluminum solder. There is already flux inside the filler rod, so the work is reduced to surface preparation, machining and heating the tube with a torch.
As the solder melts, the material flows into surface defects, forming a strong metal patch that is securely embedded in the tube wall. Some experience with aluminum brazing will be required, but in general it is much easier than welding and does not require expensive equipment.
poxipol
A popular epoxy composition of South American origin, which also works on aluminum. Such a repair cannot be absolutely reliable, but with careful application, there are known cases of successful repair of pipes, which was enough for a season. The costs are small, it is quite possible to try.
GoodYear hoses
Kits of fittings, hoses and consumables are available for making your own flexible replacement for aluminum tubing. The hoses are freon-resistant, reinforced, keep the right pressure.
You will need a special tool - a crimper, for crimping the tips. You can choose the right size for different versions of regular tubes, as well as sealing rings made of rubberized metal of different diameters.
Instructions for self-use
For a quick repair, it is allowed to use the technology of applying a fiberglass bandage on epoxy glue.
You can use the popular Poxipol.
- the surface in the defect zone is carefully degreased, cleaned with sandpaper, the metal is slightly cut with the tip of a scalpel;
- a two-component composition mixed in accordance with the instructions is applied to the repair site and to a thin fiberglass bandage;
- the fabric is wrapped around the tube and smeared on top;
- the bandage is held tightly for about ten minutes until the adhesive polymerizes.
It is necessary to work with gloves, epoxy components are poisonous and cause persistent skin irritation. The compound hardens quickly, especially at high ambient temperatures.
Watch this video on YouTube
In the event of a malfunction on the way, it is necessary to immediately turn off the air conditioner, if the automation does not do this earlier on a signal from the pressure sensor. Otherwise, operation of the compressor without lubrication will cause irreversible damage and the assembly will have to be replaced as an assembly.
One comment
Paul
Solder on aluminum, argon-arc welding, wherever it goes. But epoxy, reinforced tape, rubber hoses, such a solution to the problem. In the suction manifold tube, the pressure is small and the temperature of the tube is small. But with injection, such an epoxy repair will not work. French steam heats the pipe up to 50-60 degrees. And if it's hot outside, then generally up to 70-80. 134a gas, not the hottest in the discharge, as we say R22a, but also hot up to 60 degrees, at a pressure of 13-16 kg in the tube to the condenser. After it, the gas cools down and stops being hot.