What is the difference between dot 3 and 4. Selection and replacement of brake fluid. Brake Fluid Base

Let's think logically: "what is the most important fluid in a car?". Probably you will say that the important one, without which the car will not be able to go. And I will say that the most important liquid is the one without which the car cannot stop. We're talking about brake fluid. So, brake fluid (popularly simply "brake") is one of the most important of those. liquids in a modern car, since the safety and health of the driver and passengers depend on the correct selection and its quality. Although they jokingly say that the brakes were invented by cowards, this expression is far from being true.

But how, then, to choose a TJ so that it does not fail at the most crucial moment? First you need to turn to the technical literature, namely the instructions from the car. It absolutely always indicates which liquids to fill in and in what volume.

What else to look for when choosing and buying brake fluid?

First, any brake fluid must have a high boiling point. This is important so that it does not boil over during heavy braking and retains its properties.
Secondly, on the other hand, TJ should not freeze at negative temperatures. This is especially true for residents of winter regions.
Third, the brake fluid must provide good lubrication and corrosion protection.
Fourthly, any brake fluid must not absorb moisture from the environment, so as not to lose its properties.

In addition, TJ should not aggressively act on rubber seals, hoses and seals, so as not to harm the brake system.

Brake Fluid Classes

The main difference in the composition of TF is the base that makes up the liquid. At the moment, there are 4 classes of brake fluids on the automotive market. These are DOT-3, DOT-4, DOT-5.1 and DOT-5.

DOT-3. The basis of this liquid is ethylene glycols. This liquid is not very effective, but on the other hand is relatively cheap. But there is one significant drawback - it is very hygroscopic, so its service life is no more than one and a half years. In addition, it does not have a very high boiling point. This class of TJ can be used without any problems for the brake systems of budget cars.

DOT-4. This is the most common class of TJ to date. Such brake fluid can be bought at almost any auto shop. Yes, and in 90% of all modern cars this liquid is filled. Information on brake fluid DOT-4 is here: http://gruzovik-96.ru/store/avtohimiya/tormoznaya-zhidkost-dot-4/ This fluid is based on ethylene glycol, but with the addition of boric acid. This reduces the amount of moisture absorbed from the air. DOT-4 brake fluid is superior to DOT-3 in terms of boiling point as well as pour point. But it also actively absorbs moisture from the air.

DOT-5. The most advanced brake fluid at the moment has a DOT-5 class. Glycols are also present here, but with the addition of silicone. This brake fluid perfectly repels moisture and does not absorb it. It has a very high boiling point, low pour point and good lubricity. TJ DOT-5 does not affect rubber products and paintwork.

DOT-5.1. This brake fluid has a very similar composition to DOT-4 TF, but with the only difference - DOT-5.1 has a higher boiling point. The use of this TJ is not important in ordinary civilian cars, so it can most often be found only in racing cars, where it is really needed.

Where can you find good brake fluid?

High-quality DOT-4 brake fluid is sold in the Japanese Truck chain of stores, which has been successfully operating since 2007. The main activity of the stores is the sale of spare parts for Japanese and Korean trucks - ISUZU, MITSUBISHI, HINO, NISSAN, TOYOTA, MAZDA, KIA, DAEWOO and HYUNDAI, as well as various special fluids. In this network of stores you can also find spare parts for Korean special. technique. Almost all spare parts are in stock, which is a very competitive advantage. You can find Japanese Truck stores in Yekaterinburg and Moscow.

Brake Fluid Review Video

Conclusion.

At the end of this article, I would like to note that you do not need to save on brake fluid. The brake system must work correctly and stably. It is important not to forget about the timely replacement of the TJ in the car, since over time the brake fluid loses its properties and the efficiency of the entire system deteriorates. Take care of yourself and your cars. Thank you for your attention and see you on our website.

Brake fluid ensures the efficient operation of one of the most important systems in a car, so its importance cannot be underestimated. The resistance of Dot-4 to oxidative processes, hydrolysis, as well as high boiling point and lubricating properties directly affect the reliability of the brake circuits and the durability of the cylinders and lines of the system.

The review presents the best brake fluids on the domestic market. The rating was compiled on the basis of the declared characteristics, as well as the opinions of auto maintenance specialists. Feedback from users with a preference for one of the participating brands was also taken into account.

The best foreign brake fluids

Brake fluids of well-known foreign brands have the highest performance characteristics. Our rating includes the most popular imported products in Russia.

5 Ravenol DOT 4

Increases the effectiveness of ABS. Protects rubber cuffs and hoses from wear
Country: France
Average price: 315 rubles. (0.5 l)
Rating (2019): 4.6

A distinctive feature of this product is the absence of a negative effect on rubber seals and hoses in the car's brake system. This ensures high reliability and efficiency during operation. High operating temperatures (which occur during emergency braking) do not lead to boiling of the liquid and the formation of vapors that impair the operation of the system. The use of Ravenol DOT 4 ensures high pressure in the brake cylinders at any intensity. In addition, the operation of systems such as ABS proceeds in the best conditions, since the substance reduces friction to almost zero, increasing the resource of the system and its performance.

In any case, many manufacturers recommend pouring this brake fluid into a car. Car owners who do this on an ongoing basis fully confirm the properties of Ravenol DOT 4 - this is one of the most balanced in terms of price and practical working compositions that can be successfully used in most car brands, including domestic ones. The only limitation is that the fluid cannot be mixed with mineral-based brake fluids.

4 Mobil Brake Fluid universal DOT 4

Favorable combination of price and quality
Country: Finland
Average price: 270 rubles. (0.5 l)
Rating (2019): 4.7

Mobil Brake Fluid universal DOT 4 is a glycol based brake fluid. At the same time, the product has an affordable price, which becomes an excellent combination for most passenger cars. The liquid retains its qualities even under conditions of high humidity. Therefore, it will be necessary to fill it into the brake system less often than more expensive counterparts. In addition, a package of additives has been introduced into the composition, which provides good lubricating, anti-wear and anti-corrosion properties. At low temperature, the product has good fluidity and also exhibits a stable boiling point.

Judging by the reviews, motorists are satisfied with such qualities of Mobil Brake Fluid universal DOT 4 as accessibility, excellent operation of hydraulic drives. Some motorists note the appearance of leaks in the working brake cylinders with prolonged use.

3 Liqui Moly SL6 DOT-4

High anti-corrosion properties
Country: Germany
Average price: 688 rubles. (0.5 l)
Rating (2019): 4.7

Among the main advantages of Liqui Moly SL6 DOT-4 brake fluid, experts consider high anti-corrosion qualities. The product has excellent lubricity, which is very important for the stable operation of working mechanisms. According to a number of parameters, the German liquid is inferior to the leaders of the rating. For example, the boiling point drops sharply from 230 ° C for a new brake fluid to 155 ° C when moistened. The viscosity index is also worse, which does not allow the composition to be used in the conditions of the Far North. Based on the combination of all parameters, experts recommend this fluid to drivers who prefer a calm driving style in central Russia.

Domestic motorists highlight such advantages of Liqui Moly SL6 DOT-4 as anti-corrosion properties, gentle treatment of rubber parts. Of the shortcomings, limited use in the northern regions is noted.

2 BREMBO DOT 4

Better efficiency under extreme loads. Suitable for vehicles with ABS
Country: Italy
Average price: 360 rubles. (0.5 l)
Rating (2019): 4.8

The famous Italian brand not only produces excellent brake systems - BREMBO Dot 4 working fluid provides the most efficient brake response under extreme loads. The ability to maintain performance for a long time without changes is the reason not only for an increased resource, but also ensures the safety of the brake system from corrosion processes, and rubber hoses and cuffs using this fluid do not crack and last longer than usual.

BREMBO Dot-4 can be poured into any car, including those with an ABS system. At the same time, the efficiency of its operation is significantly improved, as evidenced by the numerous reviews of motorists. Owners who once experienced the properties of this product prefer to use this brake fluid at the next change. The lubricity of the fluid is highly appreciated, the absence of the effect of low temperatures on the operation efficiency and the extended interval between replacements, which does not affect safety at all.

What indicators of brake fluid are affected by moisture

There are several indicators that characterize the ability of the brake fluid, which is affected by moisture.

1. When braking, the temperature in the closed circuit of the hydraulic drive increases. A high water content leads to dips, similar to airing the system.
2. For the smooth operation of the brake mechanisms and the ABS unit, the product must have good lubricating qualities. In this regard, liquids of the new DOT 5 standard perform best.
3. In severe frost, the brake fluid must remain fluid, this is especially important for cars with ABS. It depends mainly on the stability of such an indicator as viscosity. The ingress of moisture definitely worsens this parameter.
4. In terms of corrosion resistance, manufacturers spend a lot of money and time inventing additives that prevent rust on parts inside a hydraulic actuator. It is very dangerous when, during emergency braking, the cylinder gets stuck in the caliper or the tightness of the metal tube is broken.

1 Castrol React DOT 4 Low Temp

High boiling point, long drain interval
A country: UK (Made in the EU)
Average price: 457 rubles. (0.5 l)
Rating (2019): 4.9

Brake fluid Castrol React DOT 4 Low Temp surpasses its competitors in many respects. Therefore, lovers of fast driving prefer to use it. First of all, the high boiling point of the liquid (265 ° C) stands out, in the class no one can boast of high resistance to heat even after a year of operation. Also pleases car owners and durability of use. The brake fluid is changed every two years. For the northern regions of Russia, this product is also ideal in terms of viscosity, which is 650 square meters. mm/s

Most motorists appreciate the technical capabilities of Castrol React DOT 4 Low Temp brake fluid. In the reviews, users note the unique properties of the product. The disadvantages of motorists include only a high price. There is dissatisfaction with the packaging of it only in bottles of 0.5 liters.

The best original brake fluids

For vehicle maintenance, each manufacturer recommends original consumables for use. This fully applies to brake fluids. With this approach, the warranty on the car is preserved, and the service life is significantly increased.

5 NISSAN KE903-99932

Best conditions for extreme braking. highest boiling point
Country: France
Average price: 485 rubles. (1 l)
Rating (2019): 4.6

Absolutely the entire range of NISSAN cars and the related brand INFIFNITI can use KE903-99932 fluid, which belongs to the Dot-4 class, in their brake systems. Given the premium class of one of these brands, you should expect the most stringent requirements for brake fluid. So, the boiling point of this product is 450 ° C, which is an order of magnitude higher than many competitors.

Not only this indicator has high values ​​\u200b\u200b- the NISSAN KE903-99932 brake fluid is frost-resistant, demonstrates better compression stability (transfers pedal pressure to the brake cylinders as efficiently as possible), suppresses oxidative processes in the system and does not lead to premature aging of the rubber circuit elements. In the reviews of owners who began to fill in this brake fluid on an ongoing basis, there is an increased service life and high efficiency of the brakes and the ABS system, even in extreme (high-speed) conditions.

4 Renault Dot-4 art. 7711 575 504

The most effective set of additives
Country: 4.6
Average price: 530 rubles. (1 l)
Rating (2019): 4.6

This manufacturer not only uses this brake fluid in their cars, but also strongly recommends that owners fill Renault Dot-4 into the hydraulic circuit during service replacement. It is she who will properly ensure the effectiveness of the operation of the brakes and provide reliable protection of the circuit from phenomena such as corrosion. The stability of performance characteristics throughout the entire period of operation largely determines the effective set of additive components.

The use of fluid in heavy crossovers and minivans will ensure high-quality operation of the brake circuit in any conditions, since Renault Dot-4 has the lowest compressibility, which allows you to most effectively transfer the pressure on the brake pedal to the system cylinders. Protective properties prevent cuffs and rubber pipes from aging, which is confirmed by the reviews of owners who use this brake fluid on an ongoing basis. By the way, many people successfully use liquid in domestic cars (including the latest LADA models) and foreign cars such as NISSAN and OPEL.

3 Honda ultra bf dot-4 (08203-99938)

Long service life
A country: Japan (manufactured in Belgium)
Average price: 779 rubles. (1 l)
Rating (2019): 4.7

The high performance of Honda ultra bf Dot-4 brake fluid can be judged by its boiling point, which is 260 °C. A high expansion coefficient with increasing use only improves the efficiency of the brake circuits. At the same time, the compatibility of the working substance allows it to be mixed with similar products from other companies, which are made on a glycol basis. Traditionally, the service life is 2 years, but the manufacturer also indicates the mileage (100 thousand km), which can be safely covered with this brake fluid.

You can safely pour Honda ultra bf Dot-4 into any Japanese car. In any case, the owners' reviews talk about the successful use of this fluid in cars such as Mitsubishi, Toyota, Nissan and others. Those who use this hydraulic filler on a regular basis, among the positive characteristics indicate a long service life, excellent performance under extreme loads and proper protection of the brake lines from oxidative processes.

2 Ford Super Dot-4

Possibility of wide application
Country: Germany
Average price: 430 rubles. (0.5 l)
Rating (2019): 4.8

Despite the fact that the Ford Super Dot-4 brake fluid was developed for the Ford model range, it can also be poured into other car brands. Thanks to the glycol base, it is possible to add product to the systems without draining the old brake fluid. It is not recommended to mix Ford Super Dot-4 with mineral compounds only. The fluid is suitable for braking systems with modern safety systems (ABS). The product has excellent performance characteristics, which makes the purchase attractive due to the affordable price. The presence of anti-corrosion additives allows you to keep all metal parts in excellent condition.

Domestic motorists are satisfied with the quality of Ford Super Dot-4 brake fluid. It provides the performance of the brake system, has an affordable price. The disadvantages include only incompatibility with mineral compositions.

1 Toyota DOT 4 Brake Fluid

The best original brake fluid
Country: Japan
Average price: 627 rubles. (0.5 l)
Rating (2019): 4.9

The original Toyota DOT 4 Brake Fluid was created for intensive use. It is ideally adapted to the systems and mechanisms of the famous Japanese automaker. The liquid has high anti-corrosion properties, which minimizes the wear of metal parts and assemblies. The product can be added to other liquids, it does not destroy the sealing elements. A distinctive feature of the composition is improved hygroscopicity, excellent expansion properties, high boiling point.

Domestic car owners highlight such positive qualities of Toyota DOT 4 Brake Fluid as excellent technical parameters, the most comfortable braking. Of the minuses, the high price can be noted. The popularity of the product is limited to use on Toyota cars.

The best domestic brake fluids

Domestic manufacturers do not lag behind foreign competitors, developing inexpensive, but effective formulations. They can be used to service both domestic cars and foreign cars.

5Gazpromneft DOT-4

The best counterfeit protection
Country Russia
Average price: 93 rubles. (0.455 l)
Rating (2019): 4.4

Gazpromneft DOT-4 brake fluid is in the price category with the toughest competition, so entering the TOP-5 of domestic products of this type can be considered a serious success. In this case, the obvious advantages were achieved by better quality and compliance with the requirements for fluids of this class (Dot-4). The high boiling point of dry matter (230 °C), the possibility of using in the Far North and the gentle effect on rubber and plastic seals in the brake circuit determine a wide range of applications for this product.

In the reviews of owners who began to pour Gazpromneft DOT-4 into cars, in addition to the already indicated advantages, there is a preservation of standard characteristics throughout the entire service life, which should not exceed 24 months. Ensuring the efficient operation of the brakes is also achieved due to high-quality lubrication (cylinders retain their mobility and do not jam), and resistance to hydrolysis (does not absorb water during operation). In addition, an important factor determining the advantage of Gazpromneft brake fluid is the highest degree of protection, which practically excludes the possibility of fakes - you can verify the originality of the product on the company's website or by sending an SMS to a special number.

4 FELIX DOT 4

Best price. Consistently high product quality
Country Russia
Average price: 67 rubles. (0.455 l)
Rating (2019): 4.6

Despite the favorable cost, FELIX DOT-4 brake fluid is in demand and popular in the domestic market for a completely different reason. The stability of performance characteristics and strict quality control guarantees a product with properties that are fully consistent with those declared by the manufacturer. Predictable quality and reliability in operation are the key features of this product. FELIX DOT-4 can be poured into both domestic and foreign brands of cars, including those with an ABS system.

The presence of oxidation inhibitors successfully counteracts corrosion processes, keeping brake system elements made of steel, brass or aluminum in excellent condition. The boiling point of the liquid is in the range of 230 ° C, which is quite sufficient for normal vehicle operation. Judging by the reviews, users consider the only drawback of this product to be a rather short service life - after 12 months of use, there may be a deterioration in performance.

3 Lukoil DOT-4

Optimum performance/cost ratio
Country Russia
Average price: 83 rubles. (0.46 l)
Rating (2019): 4.7

Lukoil DOT-4 brake fluid is sold at the best price. It is made using innovative technologies. To ensure that the product meets international requirements, patented additives are added to the synthetic base. The result is a quality fluid that is suitable for hydraulic clutch and brake drives. The product is compatible with such popular fluids as Rosa, Neva, DOT 3 and DOT 4. The brake fluid can be used in Russian and foreign cars. The composition contains corrosion inhibitors and wear-resistant components.

In reviews, many motorists consider the low price to be the main advantage of Lukoil DOT-4 brake fluid. At the same time, the product complies with international standards. The weaknesses of the composition are viscosity and lack of protection against counterfeiting.

2 Sintec SUPER DOT-4

The most popular brake fluid
Country Russia
Average price: 105 rubles. (0.455 l)
Rating (2019): 4.8

The most popular manufacturer of brake fluids in Russia is the Obninsk company Sintec. Sintec SUPER DOT-4 remains one of the most demanded products. Brakes are poured into both domestic cars and foreign cars. Numerous tests have shown that all indicators meet the requirements of international standards. For example, the temperature of a freshly unpacked liquid is 240°C, and after a year of operation it drops to 155°C. At low air temperatures, viscosity is also perfectly preserved. Therefore, it can be used in winter in cars with ABS. Only for sports cars brake fluid is not suitable.

In the reviews, most users speak positively about Sintec SUPER DOT-4. It has an affordable price and good technical parameters. Consumers consider the unstable quality of the Russian manufacturer to be a clear disadvantage.

1 Tosol-Sintez RosDOT-4

High performance properties
Country Russia
Average price: 150 rubles. (0.455 l)
Rating (2019): 4.8

In terms of its performance, brake fluid Tosol-Synthesis RosDOT-4 is in no way inferior to leading foreign brands. In terms of boiling point (255 ° C), when fresh, it surpasses even the famous leaders. After a year of use, this figure drops to 160 ° C, which also fits into the requirements of the standard. The viscosity of the product is at the level of 1600 sq. mm / s, which will not be enough to operate a car with ABS in the far north. With regular replacement, the system will be reliably protected from corrosion and wear. The liquid is recommended to be used not only in domestic, but also in foreign cars.

Motorists in the reviews consider the main advantages of Tosol-Sintez RosDOT-4 brake fluid to be an affordable price and high performance properties. The weak side of the brake fluid is the increase in viscosity in severe frost.

It is not possible to safely drive a motor vehicle if its braking system is malfunctioning. This node requires increased attention, since it is directly responsible for the safety of both passengers and the driver himself. In this regard, it is important to replace the brake fluid in a timely manner, which must be of proper quality and expiration date.

Today, in the car markets and in specialized stores, a wide selection of various brands of brake fluids is presented. The most popular of them are Castrol and Mobil, but even among the budget options there are worthy compositions with excellent characteristics, for example: rosDOT or SuperDOT.

All "dot" liquids are divided into several types: DOT 3, DOT 4 and DOT 5. Each of these compositions has its own characteristics and can only be used with certain types of machines. But, before disassembling the composition of the brake fluid DOT 4 and 3, it is worth saying a few words about the general characteristics of all fluids for the brake system of a car.

Differences in brake fluid composition

Compositions for the brake system are distinguished by their soy base. You can still find mineral liquids, the basis of which is castor oil in butyl or isopropyl alcohol. The disadvantage of such "brakes" is their low boiling point, which does not exceed 200 degrees. If the system overheats, the fluid becomes too viscous and may lose fluidity altogether as a result.

The glycol analogues are the most popular. They are made on the basis of glycols and polyglycols, as well as their esters. Such “brakes” are distinguished by a high boiling point and excellent viscosity. The only drawback is high hygroscopicity, which means that glycol formulations absorb moisture strongly.

There are also silicone brake fluids, which are considered one of the highest quality and "long-playing", but, unfortunately, they are practically not used for ordinary cars. Therefore, the best brake fluid is glycolic. This type includes "dotovo" compositions, the differences, classification and properties of which we will consider in more detail.

DOT classification

What elements are included in brake fluids, their properties, marking - all these parameters should be paid attention to when buying a particular composition. Therefore, it is worth learning more about the classification of "dotovksikh" compounds.

Initially, the abbreviation DOT looked like USDOT and stood for the United States Department of Transportation, which translates as the US Department of Transportation. As you may have guessed, this institution is responsible for the safety of motor vehicles. The same department created the specifications for the requirements and properties of brake fluids, and also separated several FMVSS No. 116 standards and named them DOT. This means that DOT is not the name of a liquid, but an international standard, according to which any company can be the manufacturer of this product.

Interesting! International standards such as SAE J 1703 and ISO 4925 came much later.

Based on this, the following compositions appeared:

DOT 3

This brake fluid is based on the simplest glycol compounds (polyethylene glycol and polyesters), and therefore its cost is an order of magnitude lower. This, of course, provides DOT 3 with great popularity among motorists. Like all glycol-based fluids, this class of fluids absorb moisture very quickly, and as a result, their boiling point decreases over time. Because of this, DOT 3 does not have a long service life, and such a “brake” will have to be changed every 2 years.

Healthy! DOT 3 fluids are not compatible with natural rubber, which is often used in brake pads. In addition, the compositions are aggressive to paintwork.

It is also worth noting that the viscosity of such liquids is not so much - 1500 mm 2 / s at -40 degrees. DOT 3 compositions are used for braking systems of vehicles with drum brakes. Also, the fluid is suitable for disc brakes located on the front wheels.

DOT 4

DOT 4 fluids have the best performance. In addition to glycols, they contain boric acid, due to which excess moisture in the composition is neutralized. This means that the boiling point of DOT 4 is stable and does not decrease during vehicle operation. However, the viscosity of this composition is the highest among other pillboxes. So you can't say she's the best. In addition, the shelf life of DOT 4 brake fluid also does not exceed 2 years. In addition, the composition of this class also manifests itself aggressively towards the paint.

Healthy! On the shelves of domestic stores, you can find formulations labeled DOT 4.5 or DOT 4+. There are no such classifications in the American system, so be careful.

However, dot 4 brake fluid, whose technical characteristics are not ideal, is in great demand among owners of cars equipped with disc brakes.

DOT 5

If we talk about which brake fluid is better, then the “Dot” composition of DOT 5 is considered the most durable. The fact is that it is made on the basis of silicone, which is distinguished by its weak hygroscopicity. Due to this, the service life of DOT 5 is 4-5 years. Other characteristics of the liquid are also close to ideal. Among the advantages worth mentioning are stable viscosity, high boiling point and much more. In addition, the composition repels moisture and behaves neutrally towards rubber elements or paintwork.

But, in every barrel there is a fly in the ointment. The ability to repel excess water will have to be attributed to the disadvantages of DOT 5, since excess moisture does not mix with the liquid, but gradually accumulates in the lower parts of the brake system. As a result, the resulting water "apedinx" freezes in winter and interferes with the operation of the system. Another problem with DOT 5 is the high degree of aeration, i.e. air saturation. That is why such fluids are strictly forbidden to be used for cars with ABS. Well, for those who, as luck would have it, are the owners of just such machines, a special composition was developed.

DOT 5.1/ABS

Fluids of this class are made on the basis of glycols, but, in addition, they contain a large number of additional additives. Due to this, DOT 5.1 is characterized by a high boiling point, low viscosity and neutrality to rubber gaskets. However, such compositions still corrode the paint.

Such brake fluids circulate freely through the system, improving the performance of the brakes themselves. Due to these properties, DOT 5.1 compounds are used for racing cars, sports cars and motorcycles. The service life of such a liquid is 3-4 years.

With the advent of all these classifications, a completely logical question arises - what happens if you mix different classes of liquids?

Can DOT liquids be mixed?

It should be said right away that the brake fluid, the composition of which is designed for ABS, should under no circumstances be mixed with other pillboxes. Active additives in DOT 5.1 are not intended for use with other types of liquids. Therefore, mixing even DOT 5 with DOT 5.1/ABS is not allowed. Elements of different chemical composition and other components, when mixed, will create an unpredictable cocktail that will not lead to anything good.

Mixing glycol fluids with silicone fluids is also not recommended. Under the influence of chemical reactions, you will receive a composition that will not meet existing requirements.

The only two compounds that behave "friendly" are DOT 3 and DOT 4, they can be mixed. However, there is one important feature here. The higher class fluid must be added to the composition of the lower class. Accordingly, it is recommended to add DOT 4 to DOT 3. Due to this, you will improve the characteristics of the original liquid poured into the system. However, if you break this rule, nothing bad will happen.

In custody

Since most brake fluid has the ability to absorb moisture, when buying a composition, it is imperative to pay attention to the packaging. It should be intact, without creases and damage. It is best to purchase liquids that are sold in bottles with additional tamper-evident protection, or they can be bottles with foil-sealed necks.

For any vehicle, the state of the brake system must always be in good condition. Otherwise, almost everyone is at risk of life: the driver, passengers and other road users. Therefore, it is important not only to carry out maintenance and replacement of worn parts in a timely manner, but also to control the level of brake fluid. With its lack, the necessary hydraulic pressure will not be created, which can lead to partial pressing of the pads. There are various products on the market, including Dot 4 brake fluid.

Like engine oil, this material can also be considered consumable, since it needs to be changed regularly, although not with frequent intervals. Brake fluid has a significant impact on the efficiency and technical condition of almost all parts of the system. And there are serious requirements for it.

Requirements

During the operation of the car, the driver from time to time activates the brake system as needed. During operation, the pads, which are pressed against the disc with force, thereby slowing down the movement of traffic, they become very hot. The heat from the pads spreads further - to the piston, caliper body. They also heat up the brake fluid itself.

In this regard, the main requirement for Dot 4 brake fluid appears - it must have an elevated boiling point. This will prevent brake pedal failure. Due to the increase in speed, along with complex traffic, castor alcohol liquids have already lost their relevance. They no longer met the needs of many vehicle owners, and then the Dot 4 standard appeared.

Corrosion of the brake line is a dangerous phenomenon. To avoid this, the liquid is made on a hygroscopic polyethylene glycol basis. However, it must be stored in a container with a tightly closed lid. If moisture gets into the liquid, corrosion processes will inevitably begin. But besides this, the liquid diluted with water now boils already at a low temperature. In this case, failures are not ruled out, which usually leads to emergency situations.

The efficiency of the entire vehicle system is directly related to the viscosity that any Dot 4 brake fluid or any other standard has. . For most modern cars with ABS, this is especially critical. Its solidification leads to disruption of the valve body. For some models, course stabilization is associated with an anti-lock braking system. As a result, this leads to a deterioration in vehicle controllability.

Dot classification

The Department of Transportation Management in the United States began to divide the brake fluid into several classes, which was opened back in 1966, but officially came into its own only a year later. According to this standard, all products are divided into classes depending on their properties. And since this standard prescribed the most optimal requirements for Ate Dot 4 brake fluid, other specialists from almost all countries of the world agreed with it.

The American standard identified 4 classes:

1. dot 3.
2. dot 4.
3. dot 5.
4. Dot 5.1.

In addition to the four classes listed, there is another variety - Dot 5.1 / ABS. This product is intended for vehicles that have an anti-lock braking system.

All the necessary information regarding their properties and application is indicated in the attached instructions. But these compositions have nothing in common with the American classification.

dot 3

Such a product is inexpensive due to the use of the simplest glycol compound. However, it should be borne in mind that it is prone to the ability to absorb moisture, due to which the composition boils at a lower temperature. In terms of service life, we can say that Dot 4 brake fluid can last 2 years.

Dot 3 products have an average viscosity (1500 mm 2 /s) at a temperature condition of -40°C. In a fresh state, the liquid boils at 205°C, and with a moisture content (3.5%), it is already below 140°C. The composition is made with an amber tint, but transparent products are also found. According to these properties, it can be safely ranked among the "gold standard" among other analogues.

Typically, such a liquid is poured into the brake system of cars that are equipped with drum brakes on the rear wheels and disc brakes on the front. But it is worth considering that the use of the Dot 3 class is unacceptable in the presence of rubber brake pads. In addition, the liquid can ruin the paintwork of the body.

Dot 4

Brake fluids of this class are considered more advanced than Dot 3. And all because of the content in its composition of various additives that help bind moisture that can get out of the air.

dot 5

Brake fluids of this class are produced using silicone. Due to its properties, the characteristics of the composition are brought to an almost ideal state. In particular, this is a high boiling point, which does not fall below 260°C and a consistently low viscosity - at least 900 mm 2 /s at a temperature of -40°C.

Among other worthy advantages, it is worth highlighting the ability to repel water. Whereas the characteristics of Dot 4 brake fluid allow it to bind moisture. In addition, the liquid does not have an aggressive effect on rubber seals. The same applies to paint finishes. But what is more valuable - such brake fluids have a rather long resource of up to 4-5 years.

However, there is a significant drawback. Due to the fact that water is able to repel the liquid, their mixing does not occur and moisture begins to accumulate in the brake line. And when the water freezes in winter, it becomes a serious hindrance to the operation of important parts. In addition, Dot 5 products have a high degree of oxygen saturation. It is for this reason that it is forbidden to use these compositions for cars with an ABS system installed.

Dot 5.1

Brake fluid of this classification can also rightly be considered almost perfect. Perhaps there is a better option, like Liqui Moly Dot 4 brake fluid, but not as much. The boiling point is the highest in comparison with other classes, and the viscosity is the lowest.

Due to this, it moves freely along the brake line, increasing the efficiency of its elements. Due to also almost ideal characteristics, liquids are successfully used in the field of sports.

However, the ability to absorb moisture significantly reduces the life of the brake fluid to one year. Interestingly, there is no connection between the Dot 5.1 class and Dot 5, which causes misunderstanding on the part of Russian car owners.

Dot 5.1/ABS

We can say that this is a separate class that will please many owners of cars with an ABS system. This brake fluid has a mixed composition, which, in addition to silicone, also includes a glycol compound.

Along with a high boiling point, the liquid exhibits lubricating properties. Almost the same characteristics have an analogue in the face of super Dot 4 brake fluid. It also contains specially designed additives to improve performance. The fluid does not affect the rubber parts of the brake system and has a low viscosity.

However, due to the presence of glycols, the liquid can corrode the paint, so it is important not to let it get on the surface of the car body.

Best Products

In order for the car to work flawlessly for a long time, it is necessary to fill in only high-quality liquid. The best products can be found among both foreign manufacturers and domestic craftsmen.

Among many products, the leading position is occupied by a brake fluid agent - Dot 4 Castrol React Dot 4 Low Temp. According to the American standard, it belongs to the fourth class, however, in terms of boiling point, it exceeds its requirements. In its pure form, the liquid will boil at 265°C, with the inclusion of moisture (3.5%) - 175°C. Consumables must be replaced at least once every two years.

The end of Low Temp is worth it for a reason. Compared to other Dot 4 fluids, the fluid has a very low viscosity of about 650 mm2/s. For those consumers who live in the northern regions, this will be the best choice.

The best domestic brake fluid is represented by the Ros Dot -4 brand. The Dzerzhinsky plant produces good products that boil at a temperature of 255 ° C, having a viscosity of 1600 mm 2 / s. At the same time, the price of brake fluid is low, which is only to the benefit of many Russian consumers. And if you regularly replace it, you can protect the brake system of a modern car from corrosion.

Fluid interchangeability

The advent of brake fluid classification inevitably leads to the question, can they be mixed and what can happen? Yes, some species are similar in composition, but there are differences.

All fluids that are intended to work with categorically cannot be mixed with other classes. Dot 5.1 active fluid additives are not compatible with other fluid formulations. It is not allowed to combine such classes: Dot 5 and a close variety - Dot 5.1 / ABS.

If you mix fluids that have a different chemical composition, you get an explosive mixture that will not help, but rather harm the brake system. The same applies to the combination of glycols and silicone - the resulting composition will not satisfy the quality. Whatever the composition of the brake fluid, the price should not be the main selection criterion!

But the two compositions are still compatible with each other - after pouring a class 3 liquid, you can then switch to Dot 4. An important condition: liquids with a higher class cannot be mixed with a composition of a lower class. The above example is a fulfillment of this condition.

The serviceability of the braking system of the car affects the safety of its driver and passengers. Today's article will reveal the topic of choosing a brake fluid. We will talk about what DOT 4 is, which product on the market is better to use and what to consider when choosing.

What is DOT? Classification and composition

DOT is an abbreviation for the US Department of Transportation, which deals with the safe use of various vehicles. It was the specialists of this department who created certain requirements for the fluids used in the brake systems of cars. The result is an international standard. Over time, the following classification was created:

• DOT-3;
• DOT-4;
• DOT-5;
• DOT-5.1.

Liquids of the DOT-3 and DOT-4 class are based on polyethylene glycol and polyesters of boric acid. But DOT-5 is a silicone-based brake fluid. In addition to these basic components, additional additives are used in the products of different companies, so the exact composition is usually not disclosed.

Recently we wrote about which brake pads are better to choose. Information is very useful -

The issue of interchangeability of brake fluids of different groups is quite relevant. We advise you to follow the recommendations of the specific vehicle manufacturer. Also, compatibility information is usually provided on the product label.

Note that DOT 5.1/ABS fluids are not recommended to be mixed with other products.

Let's move on to an overview of the main DOT 4 brake fluids on the market, which will help you choose the best option.

Russian developments

We have made an overview of the most famous and popular products on the market. Do not think that foreign brake fluids are definitely better than Russian ones, since the price is really different, but the quality may be in doubt.

Lukoil DOT 4

According to official data, this brake fluid boils at 240°C when dry and at 170°C when wet. This is good enough for most drivers. The advantages of this product are high quality, stable performance and low price.

One of the features is the almost complete absence of Lukoil DOT-4 fakes, which indicates a high level of protection. A very worthy option to buy, but we will consider other popular means.

ROS DOT 4

This is a product of the Russian company Tosol-sintez. The boiling point reaches 255°C, but already 12 months after the start of use, this figure is only 100°C. Low temperatures do not affect the viscosity of the liquid. It is in stable demand in the Russian Federation and other CIS countries. According to the promises of the developers, it provides good protection against corrosion processes.

Advantages:

• low price;
• stable viscosity;
• initially high boiling point;
• compliance with the DOT 4 standard.

Flaws:

• Significant deterioration in performance after 12 months of use.

SINTEC Super DOT 4

The manufacturer SINTEC also managed to establish itself well in Russia. Note that this is the most affordable product on the market. Although the range of fluids is very wide, they are not recommended for use on premium cars. Production is carried out in the Moscow region.

The boiling point of the product is 240°C, after 12 months of use it drops to 150°C. At low temperatures, the viscosity of SINTEK Super DOT 4 does not change during 24 months of operation. The reason for the ambiguity of reviews about SINTEC Super DOT 4 is that the quality of the product is very dependent on the batch.

Advantages:

• affordable price;
• good viscosity, which does not depend on the temperature regime;
• high boiling point;
• DOT 4 compliance.

Flaws:

• significant dependence of quality on the party.

Felix DOT 4

Brake fluid Felix DOT 4 can be used in both brakes and clutches. The product contains a set of additives that provide reliable protection of parts and mechanisms from the negative effects of corrosion and premature wear.

The composition boils at a temperature of 230 ° C, and its viscosity when the temperature drops to -40 ° C is the initial 1800. At the same time, like many other liquids, it gradually loses its properties after 12 months of active use.

Advantages:

• low price;
• compliance with the international standard;
• a large percentage of positive feedback from drivers.

Flaws:

• some reviews indicate too early boiling;
• deterioration in performance in the second year of use.

Foreign developments

By studying the opinion of many drivers on the Internet about which DOT 4 brake fluid is better, we met good reviews about foreign brand products. The quality is usually quite good, but the price can be disappointing.

Liqui Moly DOT 4

We will not write about this manufacturer for a long time, as he is well known in the automotive market. The development of this company has a boiling point of 230°C, but after a year this number drops to 155°C. Therefore, there is virtually no significant difference between it and Russian counterparts. Experts note a significant increase in the viscosity of this product with a drop in air temperature, so it should not be used by residents of the northern part of the Russian Federation.

Advantages:

• acceptable price;
• corrosion protection;
• high boiling point.

Flaws:

• increase in viscosity at low temperatures;
• deterioration of properties one year after the start of operation.

Castrol DOT 4

Castrol DOT 4 is one of the best products on the market in the brake fluid segment. It is excellent even for use in extreme conditions. Viscosity does not change even when it is -40°C outside. The declared boiling point is 265°C, and these figures are maintained throughout the entire service life (24 months).

Advantages:

• maintaining viscosity at sub-zero temperatures;
• suitable for use in vehicles with ABS;
• constant boiling point for 2 years of use;
• DOT 4 compliance.

Flaws:

• high price;
• sold in small containers.

Bosch DOT 4

This company is also known for its quality designs and affordability. During the first year of use, the boiling point of Bosch DOT 4 is 230°C, but then drops to 160°C. The viscosity remains at its original level. It is the stable viscosity that allows this product to be used in the north of the Russian Federation.

Advantages:

• affordable price;
• stable viscosity;

Flaws:

• deterioration of properties after 12 months of use.

Choosing a brake fluid is necessary taking into account the style of driving. If you prefer an aggressive style, we advise you to stop at Castrol DOT 4. But Russian products will be a good solution for a moderate driving style. Pay enough attention to the issue of viscosity, since cars in Russia are used in difficult climatic conditions. The development of Liqui Moly will be able to ensure the stable operation of the car's brake system. It will protect the elements from wear and corrosion processes.

We recommend taking into account the requirements of the vehicle manufacturer. This information can be found in the user manual. There you will find only data on a suitable class of liquid. The final decision depends on the cost, driving style and feedback from other users.