Choosing and completely replacing antifreeze

Over time, the cooling fluid «aging» occurs: the quantitative and chemical composition of the components changes, and as a result — overheating and engine failure. Timely complete replacement of antifreeze will help to keep the mechanisms working, as well as to protect the nodes and parts of the engine from premature wear.

Antifreeze which to choose

What is antifreeze

Antifreeze is the name of a separate category of non-freezing liquids that serve to cool the DVS. IN the process of operating powerunits prevent damage to engine components and ensure stable operation of mechanisms in conditions of low and high temperatures.

The main feature of non-freezing solutions is the low expansion rate. If clean water, in case of freezing, increases in volume by 9%, then coolant by 1.5-3.5%. In addition, OJ does not crystallize, and turn into a loose plastic mass, which does not cause any harm to the engine.

Classification of antifreeze by composition

According to the structure of the OJ are divided into the following categories:

  1. ethylene glycol;
  2. glycerin;
  3. Salt;
  4. Alcohol.


They are made on the basis of two-atomic alcohol, distilled water and additives. When frozen, ethylene glycol solutions do not crystallize or damage the cooling system’s shirt.


They have a low freezing threshold. With a reagent concentration in water of 67% or more, the lower crystallization threshold is 50 degrees Celsius. The boiling point is 110-120 degrees Celsius. Substances are characterized by high lubricating and anti-corrosion qualities.


This includes ethyl, methyl, isopropyl, they can also act as antifreeze. However, their boiling point is below 100 degrees Celsius. Therefore, the use of such solutions is possible only in low-temperature climatic zones.


They are water mixtures of calcium chlorides, magnesium, sodium. Under certain conditions, electrochemical corrosion may be contributed to. For wide use, a set of modifying additives is required, which significantly affects the cost of the product.

Antifreezecanes can be produced in the form of concentrated compositions or in the form of ready-to-eat solutions.

Classification of coolant by appearance

According to the set of modifiers, THE OJs are divided into 4 categories:

  1. Traditional;
  2. carboxilate;
  3. Hybrid
  4. lobrid.

Traditional non-freezing liquids consist of glycoly compounds, water and a set of inorganic additives:

  • phosphates;
  • silicates;
  • Aaminoes;
  • Borats;
  • Nitrite.

The main drawback is the short life of the 60,000 km, as well as the risk of silicate precipitation, which disrupts the heat sink. Such composites are used only in older car models.

Carboxilates are made on the basis of ethylene glycols, water and organic additives. Considered the best in its class, as the main component of modifying additives are carbon iced salts, which have high anti-corrosion and antioxidant properties. The lifespan is from 3 years or more.

Hybrid antifreezes are chemical mixtures of traditional and carbon antifreeze taken in certain proportions.

Lobrids are substances consisting of water, ethylene glycol and mineral additives. Suitable for all modern cars. In their characteristics, they are comparable to carboxilate antifreezes.

Operating requirements for coolant

The main task of antifreeze is to protect the engine from overheating, and to ensure the safety of the cooling system in winter.

How to choose antifreeze for a car

Requirements for cooling liquids:

  • High thermal conductivity and heat capacity;
  • The low threshold for freezing begins
  • Boiling point above 110 degrees Celsius;
  • Optimal viscosity index in the working range of temperatures;
  • High anti-foam properties;
  • anti-corrosive and antioxidant qualities;
  • compatibility with polymers and non-ferrous metals.

Replacing antifreeze with your own hands

A complete replacement of the liquid in the cooling system is required in the following situations:

Replacing antifreeze

  • The lifespan is over.
  • Engine overheating.
  • The color of the solution has changed.
  • The clouding of the mixture, and the fallout of the insoluble sediment.
  • Repair work in the engine.

Filling the new cooler is divided into three stages: the drain ingesher of the old; Washing; filling the system with pure antifreeze.

How to drain antifreeze completely


Replacing antifreeze with flushing

  1. Install the car on a pit, lift or overpass.
  2. Remove the lids from the expansion tank and the neck of the radiator.
  3. Open the crane on the cylinder block.
  4. Drain the residues of liquid from the radiator.
  5. Close the valves and proceed with the next operation.

Flushing the system

It is desirable to wash the cooling system in any situation. The only reason to avoid this procedure is if the old antifreeze is up to date or the new liquid belongs to the same class as the old composition.

Is antifreeze replacement necessary?

There are two ways to flush the engine. The first is the use of a special composition (the instruction is on the back of the package). The second is that if the cooling system is relatively clean, you can use tap water with the addition of 15-20% of the new OJ.

For washing with water solution:

  1. Pour into the expansion tank water mixture.
  2. We start the engine for 15-20 minutes.
  3. We silence the engine and give a little stand.
  4. Open the cranes, and drain the liquid.

If the quality of the drained work does not meet the requirements, you can re-pour the washing solution, and repeat the process.

Filling the system with a new antifreeze

Replacing coolant

We close the drain valves, and through the expansion tank pour pure antifreeze. The volume of the liquid is first fixed in the neck of the radiator, and then oriented on the marks on the body of the expansion tank. Start the engine, and give it 5-10 minutes to work on idle speeds.

Then we check the tightness of the joints (pipes, cranes), and look at the level of liquid in the expansion tank. If necessary, add antifreeze, install and pull up the lids of the tank and radiator. The car is ready for further operation.

Алексей Назаров/ автор статьи

Руководитель сети СТО с огромным стажем работы.

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