The modern approach to repairing household appliances often comes down to calling a specialist, however, owners of classic models such as ZILoften prefer to restore units on your own. These reliable machines, created according to Soviet standards, require a specific approach, especially when it comes to the refrigerant circulation system. The loss of freon is not just a lack of cold, it is a signal about the depressurization of the circuit, which cannot be ignored.
Before taking active steps, it is necessary to clearly understand the physical essence of the process. Refilling the refrigerator is not just adding gas to the system, but a complex engineering procedure that requires evacuation and precise dosage. Errors at this stage can lead to failure of the compressor or complete destruction of the heat exchanger.
In this article we will analyze in detail all the stages of working with refrigerants used in ZIL equipment. You will learn how to determine the type of gas needed, what tools are needed for professional work and why The tightness of connections is checked with a soap solution, and not by ear. The nuances of working with various types of freons that could have been replaced during previous repairs will also be considered.
Diagnostics of leaks and preparation of equipment
The first and most important step is to detect the place where the refrigerant has left the system. In older models ZIL the evaporator or foamed sections of the pipeline often suffer. If you hear hissing or see oily spots on the tubes, this is a clear sign of damage. Without eliminating the cause of the leak, any refueling will be a waste of time and resources.
To carry out the work, you will need a specialized set of tools. You cannot use homemade methods or automobile compressors, as they do not provide the necessary pressure and purity of injection. Vacuum pump is a mandatory element of equipment, without which it is impossible to remove moisture and air from the circuit.
List of necessary equipment for professional refueling:
- 🧊 Vacuum pump to remove moisture and air from the system.
- 🔧 Manometer station (manifold) with hoses for R12, R134a or R600a.
- ⚖️ High precision electronic scales for weighing a freon cylinder.
- 🔥 Solder torch for sealing copper tubes.
⚠️ Attention: Before starting any work with the tubes, make sure that the system is completely defrosted and dry. The presence of water in the circuit during soldering will lead to the formation of acid inside, which will kill the compressor in a few months.
It is also important to prepare the workplace. It should be well ventilated, since some types of freons can release toxic compounds at high temperatures. Use safety glasses and gloves to avoid burns from cold gas or solder.
Choosing the type of refrigerant for ZIL models
Historically, refrigerators ZIL were designed to work with various refrigerants. In older Soviet models, freon R12 (difluorodichloromethane) was most often used. This is an inert gas, which, however, is prohibited for production in many countries due to the negative impact on the ozone layer, although it is still found in old reserves.
More modern modifications or those that underwent major repairs in the 90s and 00s can be adapted to R134a. This gas requires the use of synthetic oil (POE), whereas R12 ran on mineral oil. It is strictly forbidden to mix these oils, as they form an insoluble precipitate that clogs the capillary tube.
There are also rare cases when equipment is switched to isobutane (R600a). It is an explosive gas operating at lower pressure. Charging with such a refrigerant requires special care and the absence of any spark sources within a radius of several meters.
Comparative table of the main characteristics of refrigerants:
| Freon type | System pressure | Oil type | Features |
|---|---|---|---|
| R12 | Average | Mineral | Toxic when burning, prohibited |
| R134a | High | Synthetic (POE) | Hygroscopic, afraid of moisture |
| R600a | Low | Mineral | Explosive, economical |
To determine what exactly is poured into your unit, carefully inspect the compressor. Technical data is often stamped on its body or a tag is glued to it. If the tag is missing, focus on the year of manufacture: until the mid-90s, this is almost guaranteed. R12.
The process of vacuuming the system
After you have found and sealed the leak, and also replaced the filter-drier, the critical stage begins - vacuuming. Air and moisture vapor remaining inside, when mixed with refrigerant and oil, form aggressive compounds. Vacuum pump allows you to reduce the pressure in the circuit to a level at which water boils at room temperature and evaporates.
Connect the hose from the vacuum pump to the service to the fitting (or to the process pipe, if there is no fitting). Turn on the pump. The operating time depends on the pump power and the volume of the system, but for refrigerators ZIL usually requires from 30 minutes to 1 hour of continuous operation.
☑️ Evacuation checklist
During operation, the pressure gauge needle should drop into the blue zone (vacuum). If the arrow begins to creep up after turning off the pump, it means that there is still a leak in the system. In this case, it is necessary to check all solder joints again with a soapy solution.
⚠️ Attention: Never try to blow out the system with your own mouth or a tire inflator. The blown-in air contains moisture, which will instantly freeze in the capillary tube upon first start-up, creating an ice plug.
There is a common misconception that you can “blow out” the system with freon before vacuuming. In a garage repair environment, this is only permissible as a last resort, but it will not replace full vacuuming. High-quality removal of moisture is the key to a long compressor life.
Refrigerant charging technology
The most crucial moment is the introduction of freon into the system. There are two main methods: weight charging and pressure/temperature charging. For beginners, the safest and most accurate method is the weighing method. The exact weight of the refrigerant is always indicated on the compressor ZIL or in the technical documentation (usually from 100 to 150 grams).
Place the freon cylinder on an electronic scale. Reset the readings (tare). Open the valve on the cylinder and carefully open the valve on the pressure gauge, allowing gas into the system. Keep an eye on the scale. As soon as the readings reach the desired value (for example, 130 grams), close the valve on the cylinder.
What to do if there are no scales?
If there are no scales, you can navigate by the current consumption of the compressor and the temperature at the evaporator. The current should not exceed the rated current indicated on the motor label. However, this method requires experience and carries the risk of error.
After the initial charge, the compressor must be started. Let the system run for 10-15 minutes. During this time, watch for freezing of the evaporator. The cold should be distributed evenly. If the tube at the outlet of the compressor (discharge) is too hot, and the return (suction) does not freeze, there may be not enough freon. If the return pipe is covered with frost right up to the compressor, there is an excess of freon.
It is important to remember about capillary tube. It is this that creates the necessary resistance to the refrigerant flow. If the system is charged correctly, then after stopping the compressor, the pressure in the system equalizes within 3-5 minutes. This allows the motor to start easily during the next cycle.
Sealing the system and checking for leaks
When you are convinced that the refrigerator is working correctly, the temperature is rising, and the cycle is proceeding normally, you can proceed to sealing. Clamp the service tube with powerful clamps in two places, leaving a small area for soldering between them. Saw off the tubing between the clamps and quickly solder the hole.
Use copper-phosphorus solder, which does not require flux to join copper to copper. The heating must be uniform so that the solder flows from all sides under the action of capillary effect. Rapid cooling of the soldering area with water is not recommended; allow the metal to cool naturally to avoid microcracks.
The final check includes:
- 🧼 Coating all seams with a soap solution to search for bubbles.
- 🌡️ Controlling the temperature in the chamber through 2-3 hours of work.
- 🔊 Listening to the operation of the compressor for extraneous noise.
After soldering, be sure to wipe the joint with a rag to remove any remaining flux (if used) or oxides. This will prevent future corrosion. The refrigerator is ready for use if it returns to operating mode and maintains the temperature during the day.
Common mistakes during self-repair
Independent repair of equipment ZIL is full of pitfalls. One of the most common mistakes is using the wrong oil. If you refill the system R134a, but there is still mineral oil from R12 in the compressor, the synthetic will coagulate into flakes. In such cases, a complete flushing of the system with nitrogen or replacement of the compressor is required.
Another common problem is underheating or overheating during soldering. Underheating leads to fistulas, and overheating burns out thin-walled tubes inside the foamed casing, which makes repairs almost impossible without opening the casing. They also often forget to replace filter drierwhich is a disposable element.
Table of common problems and their causes:
| Symptom | Probable cause | Solution |
|---|---|---|
| The refrigerator does not freeze | The capillary is clogged or there is no freon | Purge with nitrogen, refill |
| The compressor is hot | Lack of freon or air in the system | Evacuation, refueling |
| Frost on the return pipe | Refilling with freon | Bleed off excess quantity |
⚠️ Attention: If after refueling the compressor hums, but does not start, or the machine immediately knocks out, it is possible that hydraulic shock compression has occurred (liquid freon has entered the cylinder) or a wedge of the mechanism has occurred. Do not try to turn it on again without diagnostics.
Remember that old refrigerators ZIL often have a steel compressor piping, which can be severely corroded. When working with tubes, act with extreme caution so as not to break them off at the very base.
When completing the repair, make sure that all tools removed and the work area cleared. Correctly carried out refueling will give your refrigerator a second life, and it will last for many years, keeping food fresh.
Is it possible to fill a ZIL refrigerator with freon from a car air conditioner?
It is absolutely not possible. Freons have different chemical formulas and require different types of oils. Filling with the wrong gas will lead to destruction of the compressor and the need to replace it.
How many grams of freon is needed for a ZIL refrigerator?
The exact amount is indicated on the tag located inside the chamber or on the compressor. Typically for ZIL models this ranges from 100 to 140 grams. Exceeding the dose will worsen the cooling.
Do you need to change the oil in the compressor when refueling?
If you do not change the type of freon (for example, pour R12 instead of R12), then you do not need to change the oil. If there is a transition to another type of refrigerant, changing the oil and flushing the system are mandatory.
Why does the refrigerator freeze after refilling, but does not turn off?
This may indicate a freon leak (insufficient tightness), a clogged capillary system, or a malfunction of the thermostat. Air leaks through poor-quality connections are also possible.