Boiling point of brake fluid dot 4. Classification and description of DOT brake fluid. Which DOT4 brake fluids are better and how to choose them correctly

The original article and its most latest version on the website of the cycling club “Hundred”:

© 2007 - first version of the article
© November 2008 - additions
© February 2014 - additions and clarifications, illustrations updated and new ones added

DOT brake fluids

Most modern bicycle and automobile hydraulic brakes now use various grades of DOT brake fluid. The only exceptions are hydraulic brakes from Shimano and Tektro, where mineral oil of their own brand is used as a fluid, as well as some sports models of motorcycles and cars.

The designation DOT itself is an abbreviation for United States Department of Transportation (USDOT or simply DOT): the US Department of Transportation, which deals with transportation safety issues. It was this department that developed the specification minimum requirements to the characteristics of brake fluids and divided them into classes in its standard FMVSS No. 116. These classes were named and labeled according to the department that gave birth to them, and since this document technical point view did not contradict common sense (which in itself is nonsense, given that we are talking about the USA), it was successfully picked up by the world community for the classification of brake fluids.

Designation

The standard designates brake fluid classes as DOT 3, DOT 4, DOT 5 and DOT 5.1, however, on the domestic market you can also find brake fluids marked DOT 4.5 and DOT 4+. The latter is most likely the same as DOT 4.5 and both are not classified by the American standard. The DOT 5.1 brake fluid marking has nothing to do with the DOT 5 brand and this is an exception to the common sense of Americans, which we naively believed at first, within the framework of the standard.

Compound

All brake fluids except DOT 5 use polyethylene glycol in combination with boric acid polyesters as a base, while DOT 5 uses silicone as a base.

Brake fluids DOT 3, DOT 4 and DOT 5.1 have the same base and can be interchanged without any problems, according to at least within one manufacturer.

Some manufacturers use polyalkylene glycol as a base for the production of DOT 3 (and possibly other grades). Information on the incompatibility of liquids based on polyethylene glycol and polyalkylene glycol could not be found anywhere, and knowledge of chemistry as a first approximation allows us to state that such a mixture will work no worse than the original components.

It should also be separately mentioned that some brake fluids are designed to work in the braking systems of cars with ABS (anti-lock braking system), most often they are marked with the designation “ABS” added, for example DOT 5.1/ABS or this is indicated separately on the packaging.

You should not mix brake fluids, even of the same class, if one of them is designed for ABS operation, and the second is not, i.e. mix for example DOT 5.1 with DOT 5.1/ABS, because these fluids have slightly different chemical compositions of additives to reduce aeration (prevent the formation of bubbles) in the ABS system and there is no guarantee that as a result you will have a stable chemical and physical indicators fluid in the brake system.

If you have a car with ABS, then you cannot use DOT not designed for ABS or even just add it to another DOT for ABS, which is understandable. If we are talking about a bicycle and hydraulic bicycle brakes, then you can use any DOT, designed for ABS or not, preferably without mixing them.

When glycol-based fluids (DOT 3, DOT 4 or DOT 5.1) are mixed with silicone-based DOT 5 fluid, a chemical reaction occurs resulting in a compound that does not meet any brake fluid requirements and is aggressive towards seal materials.

Do not mix DOT 3, DOT 4 or DOT 5.1 with DOT 5 silicone fluid!

A complete replacement of glycol brake fluid with silicone is possible (DOT 3, 4, 5.1 to DOT 5), but this requires first cleaning and thoroughly drying the entire brake system of old brake fluid. At the same time, there is no guarantee that the material of the brake system seals will be resistant to silicone fluid, although the chances of damage to the seals by silicone fluid are quite small, because Silicone based fluid is not as aggressive as glycol based DOT. The advantages of such a replacement in the case of a bicycle are extremely unclear.

Replacing silicone brake fluid with glycol is practically impossible (DOT 5 to DOT 3, 4 or 5.1), no matter how much you flush the entire system beforehand, because glycol DOT is very aggressive and if the brake system elements were not originally designed for it, then most likely In all, the brake system seals will be destroyed.

Boiling temperature

Brake fluid is the main transmission element of the hydraulic brake mechanism, responsible for transmitting force from the brake lever to the brake pads. As you know from a physics course, liquid is practically incompressible compared to gas, and therefore all the force of the handle is completely transferred to the brake pads. The friction of the brake pads on the discs (rotors) is the very mechanical force that absorbs the kinetic energy of the movement of the bicycle (car, motorcycle, Formula 1 car) and, in other words, stops it. But according to the law of conservation, no energy disappears without a trace and the energy of movement in the brakes is converted by friction into ordinary heat, heating the pads and rotor. When heated, the liquid boils, forming bubbles of steam, which, like any gases, are subject to strong compression. By compressing the gas, it interferes with the transmission of braking force and the brakes simply stop working effectively.

The boiling point of brake fluid classes, in accordance with the standard, is presented in the following graph:

It should be noted here that this is the minimum boiling point for brake fluids, determined by the standard, i.e. in reality, it can be even higher, for example, a single DOT4 sample can have a boiling point of about 280 °C, the main thing is that it should not be lower than 230 °C

All glycol brake fluids are hygroscopic and over time the fluid absorbs moisture from the air with which it comes into contact. The value of “new” brake fluid on the graph corresponds to its normal dehydrated state, in which it is immediately after purchase, and it becomes “old” after it absorbs 3.7% of water. Since the standard does not know such a class as DOT 4.5 or DOT 4+ (in green on the graph), a study of the inscriptions on the boxes and the range of products sold showed that this is the same DOT 4, with additives that make it possible to increase some characteristics, including the boiling point . In fact, the DOT 4.5 boiling point curve can be located throughout the entire range of space from DOT 4 to DOT 5, depending on what the manufacturer stuffed there.

The standard does not share boiling point requirements for silicone 5 and glycol 5.1 liquids, but DOT 5 silicone liquid itself is less hygroscopic, which is conventionally shown on the graph by a pink curve, which at first absorbs moisture noticeably more slowly and reduces the boiling point than the red curve for DOT 5.1

Life time

The service life during which the fluid accumulates moisture and becomes old for DOT 3 and DOT 4 is 2-3 years when used in a car; in a bicycle this period will apparently be much longer. DOT 5.1 is more hygroscopic, but can contain a much larger amount of additives that increase the boiling point and bind water, so its service life in a car can reach 3-4 years, i.e. for the average life of the bicycle itself, it may well be enough entirely.

Silicone fluid DOT 5 is generally slightly hygroscopic and its service life can reach up to 10-15 years (in a bicycle), but it has a number of other problems, in particular high degree aeration due to the high air solubility and as a result, DOT 5 is prohibited for use in cars with an anti-lock braking system (ABS), but fortunately this does not apply to bicycles.

Application

But let’s now think a little with our heads about what we need. The first thought that comes to mind when reading the characteristics of the boiling point of brake fluids blatantly asks whether it is even possible to heat the brake fluid in the system to at least 150 °C, if we are initially talking about a bicycle? The imagination pictures a mad downhiller rushing with the brakes pressed from the very top of Everest to its very foot. I have seen brake rotors heated to a temperature at which it is no longer possible to touch them, but the possibility of boiling the liquid itself seems unlikely to me. Although for example for cars and motorcycles sports plan- this is a very important characteristic.

Therefore, we’ll leave the boiling characteristics to motorcycle racers and street racers, and let’s focus only on the fact that brake fluid DOT 5.1 has a large set of additives that bind water, which means it has greater anti-corrosion protection, significantly extending the service life of the entire brake system.

What happens when a liquid becomes "old" and soggy? In addition to the boiling point, which is not so important to us in reality, its other characteristics also change, for example, they deteriorate lubricating properties of brake fluid, which leads to more significant wear on the brake caliper cylinders, which push the brake pads and press them against the rotor. If the cylinders (pistons) of the caliper (caliper is a brake machine that clamps the rotor with pads) move with jamming or simply not evenly, then the pads may not open completely and rub the rotor, preventing the wheel from spinning freely and wearing out the rotor itself.

When to change brake fluid

The most optimal indicator is, of course, to change the DOT for humidity. However, measuring brake fluid moisture is not always possible in a garage environment. There are portable DOT moisture meters on sale (no larger than a marker), which only require a very small amount of liquid to determine its moisture content. The cost of such devices for monitoring the DOT condition in only one car is quite high, so such moisture meters can often be found in service centers.

If you have such a device, then use the humidity value from the graph as a guide:

If not, then change it every 2-3 years. In bicycle brakes, the total amount of brake fluid is too small to measure its moisture content for control, so change the fluid as soon as possible. in full preventively, at least once every 3-4 years, if there are no other problems. If you feel that the brakes have begun to work more tightly or the pads are decluttering worse after releasing the brakes, or if when braking the brake handle begins to noticeably sag and there is too much free play, then change the brake fluid and pump the brakes without waiting.

Viscosity

Another characteristic, perhaps the most important for us, responsible for the quality of brake performance is the viscosity of the brake fluid. The lower the viscosity, the more quickly and accurately the braking force is transmitted and the brakes respond more adequately.

The viscosity of brake fluids is shown in the following graph:

The standard defines maximum kinematic viscosity for classes, i.e. in reality it should be lower or at least not higher.

Again, it is impossible to clearly indicate the viscosity value of DOT 4.5, since in reality it ranges from 1800 to 1200. The lowest viscosity is DOT 5 and DOT 5.1 brake fluids, which makes them favorite among racers of all wheel units equipped with disc brakes. Low viscosity and, as a consequence, high capillarity not only contribute to more ideal brake operation, but also to an easier process of bleeding the brake system.

The seemingly incident that the more expensive DOT 4 has worse fluidity than DOT 3 is actually explained very simply. The increased viscosity of DOT 4 compared to DOT 3 is caused by the addition of more simple additives and additives that increase the boiling point and bind water. Brake fluid manufacturers often boast that their DOT 4 (4+, Super4, 4.5 or any other 4*) has a boiling point much higher than any DOT 5.1 and is therefore better. In practice, this DOT very often with great difficulty fits into the viscosity value of 1800, literally being on the verge of the standard or quite often not fitting into the standard at all and being essentially substandard.

The viscosity of all DOT brake fluids at a temperature of 100 °C is 1.5, i.e. the main difference in viscosity is only very noticeable at low and normal temperatures.

Interchangeability of DOT viscosity

One of the most popular questions among car enthusiasts: Is it possible to fill in DOT 5.1 if it is recommended by the manufacturer and was originally filled with DOT 3 or DOT 4? In terms of the chemical composition, as we discussed above, there will be nothing bad: you can pour and almost always it’s even better. But it makes sense to dwell on this “almost” separately. DOT 5.1 is more fluid than DOT 3 or 4, which is good for the operation of the brake system as a whole, but if the brake system itself is worn out, has play in the caliper pistons or unreliable seals, then the more fluid DOT will flow much more easily from the closed system to the outside throughout cracks and you risk being left without brakes at some point.

The reserve of brake fluid in bicycle brakes is extremely small, if not non-existent.
If the capacity of the brake system expansion tank in the car is large enough, then the DOT leaking through the cracks of the damaged brake system can be determined by the more frequent addition of DOT into the system. If after replacing DOT 3 or DOT 4 with DOT 5.1 you began to top up more often, then think about it: apparently your brake system is not sealed and you are constantly squeezing some of the brake fluid onto the street, or the gaps and seals of your car were originally designed for a thicker DOT.

If the manufacturer requires you to use only DOT 5.1, and your brakes start to leak, then there is no need to fill in DOT4, so that the leak will be less - repair or change your brakes.

Low temperatures

The lower temperature limit for long-term operation of all brake fluids is -40 °C. According to the standard, when DOT is stored at this temperature for 144 hours, it should not form sediment, crystallization or delamination. It is allowed to cool the brake fluid to -50 °C for 6 hours, also without any changes in physical condition liquids.

The temperature range does not impose any restrictions on the use of a bicycle in winter.

As for silicone fluid DOT 5, due to its non-hygroscopicity, it does not absorb moisture that has entered the hydraulic system and does not mix with it, which can lead to water settling at the lower points of the hydraulic system, i.e. in the pistons and freezing of this water in winter. Although DOT 5 silicone has a longer lifespan overall, the effects on the brake system when the brake fluid becomes too wet and aged can be much worse than with DOT 3, 4, or 5.1 brakes because the water in the DOT 5 system is unbound. .

Marketing retreat

Many manufacturers, adhering to the classification in accordance with the standard, produce brake fluid with higher performance than is required for theirs and even a higher class, such as the restless DOT 4.5 or the sometimes found Super DOT 4 or the almost universally sold DOT 4-plus.

I will not name the manufacturer of the latest brand, I will only note that the manufacturer claims on all points characteristics that are significantly superior to even DOT 5.1 in the standard. So why then is it still 4 and not 5.1? The answer lies in the detailed analysis of the contents that the liquid must undergo during certification and the marketing desire to sell what is available at a higher price.

Most often, products are marked DOT 4+, DOT 4.5, Super DOT 4, etc. really superior in terms of parameters the same DOT 4, but do not meet any individual requirements of a higher class , for example, may not contain sufficient (or may not contain at all) anti-corrosion additives, the presence of which is required by the DOT 5.1 marking, or may have a very high viscosity. So the main thing to understand is that even if the brake fluid is MegaPuper DOT 4.999-plus, it is still essentially ordinary DOT 4 and nothing more.

Color and product marking of brake fluids

FMVSS Standard No. 116 requires manufacturers to color brake fluids certified for use in automobiles and motorcycles in order to prevent accidental mixing of chemically incompatible fluids with each other:

For DOT 3 or 4, they must have a clearly readable marking on the container indicating the class, literally “DOT 3” or “DOT 4”, respectively.

DOT 5 on a silicone base, must be marked: “DOT 5 SILICONE BASE”
DOT 5.1 is designated as "DOT 5.1 NON-SILICONE BASE"

Hydraulic mineral oil for brake systems

This is a completely different type of brake fluid, not at all DOT compliant, but quite common in bicycle brakes, occasionally found in motorcycles, and almost never in cars. For this reason, standard 116 contains only a few general comments.

First of all, if the brake system is designed to use either DOT or mineral oil as brake fluid, then you absolutely cannot replace one with the other!

The seals and rubber-based components used for DOT hydraulic systems are not compatible with mineral oil and will most likely destroy the seal of the brake system very quickly. Likewise, oil-resistant seals and components of brake systems operating on mineral hydraulic oil are not designed for chemically aggressive DOT fluids.

Hydraulic oil packaging should say "HYDRAULIC SYSTEM MINERAL OIL". Although the standard requires mineral oil for hydraulic brakes to be colored in green color, many manufacturers of such oil do not target their products for cars and motorcycles, but produce them exclusively for bicycle brakes, and therefore are not limited in any way in product labeling. For example, Shimano hydraulic brake oil is often colored bright red, while its cheaper substitute from another manufacturer was poisonous blue.

It should be noted that using oil rather than DOT in brakes has its advantages:

• better lubrication effect and less wear on moving parts (pistons)
• the oil is not as toxic to humans and nature as DOT

Oil also has its disadvantages:

• works worse when low temperatures, some already at 0°C thicken significantly
• when the leak hits the rotors or pads, it lubricates them and the brakes stop working

Good luck with your braking :)

Brake fluid is a special substance that fills the brake system of a car and plays a role in its operation. vital role. It transmits the force from pressing the brake pedal through a hydraulic drive to the brake mechanisms, due to which braking and stopping occurs vehicle. Maintaining the required quantity and appropriate quality of brake fluid in the system is the key to safe movement.

Purpose and requirements for brake fluids

The main purpose of brake fluid is to transmit force from the master cylinder to the brake mechanisms on the wheels.

Brake fluid

The stability of a car's braking is also directly related to the quality of the brake fluid. It must meet all the basic requirements for them. Additionally, you should pay attention to the manufacturer of the liquid.

Basic requirements for brake fluids:

1. High boiling point. The higher it is, the less likely it is for air bubbles to form in the liquid and, as a result, a decrease in the transmitted force.
2. Low freezing point.
3. The liquid must maintain the stability of its properties throughout its entire service life.
4. Low hygroscopicity (for glycol bases). The presence of moisture in the fluid can lead to corrosion of brake system components. Therefore, the liquid must have the property of minimal hygroscopicity. In other words, it should absorb moisture as little as possible. To do this, corrosion inhibitors are added to it, protecting the system elements from the latter. This applies to glycol-based fluids.
5. Lubricating properties: to reduce wear of brake system parts.
6. Absence harmful effects on rubber parts (o-rings, cuffs, etc.).

Brake fluid composition

Brake fluid consists of a base and various impurities (additives). The base makes up up to 98% of the composition of the liquid and is represented by polyglycol or silicone. In most cases, polyglycol is used.

Ethers act as additives that prevent the oxidation of the liquid by atmospheric oxygen and during strong heating. Additives also protect parts from corrosion and have lubricating properties. The combination of brake fluid components determines its properties.

You can mix liquids only if they consist of the same base. Otherwise, the basic performance characteristics of the substance will deteriorate, which may lead to damage to the brake system components.

Brake fluids are divided into several types. The classification is based on the boiling point of the liquid and its kinematic viscosity according to DOT (Department of Transportation) standards. These standards are adopted by the US Department of Transportation.

Kinematic viscosity is responsible for the ability of fluid to circulate in the brake system line at extreme operating temperatures (from -40 to +100 degrees Celsius).

The boiling point is responsible for preventing the formation of a vapor “plug” that occurs when high temperatures. The latter can lead to the brake pedal not working at the right time. The temperature indicator usually takes into account the boiling point of the “dry” (without water impurities) and “moistened” liquid. The proportion of water in the “wetted” liquid is up to 4%.

Classification of brake fluids

There are four classes of brake fluids: DOT 3, DOT 4, DOT 5, DOT 5.1.

1. DOT 3 can withstand temperatures of 205 degrees for “dry” liquid and 140 degrees for “wet” liquid. These fluids are used under normal operating conditions in vehicles with drum or disc brakes.
2. DOT 4 is used on vehicles with disc brakes in city traffic (acceleration-deceleration mode). The boiling point here will be 230 degrees for a “dry” liquid and 155 degrees for a “wet” one. This fluid is most common on modern cars.
3. DOT 5 is silicone based and is not compatible with other types of fluids. The boiling point for such a liquid will be 260 and 180 degrees, respectively. This liquid does not corrode paint and does not absorb water. As a rule, it is not used on production cars. It is usually used on special vehicles operating in conditions of extreme temperatures for the braking system.
4. DOT 5.1 is used on sports cars and has the same boiling point as DOT 5.

The kinematic viscosity of all types of liquids at a temperature of +100 degrees is no more than 1.5 sq. mm/s., and at -40 it varies. For the first type, this value will be 1500 mm^2/s, for the second - 1800 mm^2/s, for the latter - 900 mm^2/s.

As for the advantages and disadvantages of each type of liquid, the following can be distinguished:

• the lower the class, the lower the cost;
• the lower the class, the higher the hygroscopicity;
• impact on rubber parts: DOT 3 corrodes rubber elements, and DOT 1 fluids are already fully compatible with them.

When choosing brake fluid, the car owner must follow the manufacturer's instructions.

Features of operation and replacement of brake fluid

Brake Fluid Operation

How often do you change brake fluid? The service life of the fluid is set by the car manufacturer. Brake fluid must be replaced on time. You should not wait until her condition approaches critical.

The state of a substance can be visually determined by its appearance. The brake fluid should be homogeneous, transparent and without sediment. In addition, car services evaluate the boiling point of a liquid using special indicators.

Required period to inspect the condition of the fluid - once a year. Polyglycol fluid needs to be changed every two to three years, and silicone fluid every ten to fifteen years. The latter is durable and chemical composition, resistant to external factors.

Reading time: 4 minutes.

The stability of the brake system directly depends on the quality of the brake fluid. The effectiveness of brakes has a direct impact on the safety of passengers, the driver and the safety of the vehicle. You can only feel safe when the system is filled with a high-quality composition, for example, Castrol Brake Fluid Dot 4.

Description of brake fluid Castrol Brake Fluid DOT 4

Castrol Dot 4 is a brake fluid with an extremely high boiling point. It has a yellow transparent color and a uniform consistency without any dry residue.

Castrol Dot 4 brake fluid is developed on the basis of polyalkylene glycol and multi-component boron ethers with the subsequent addition of an additive package. Corrosion inhibitors protect the brake system from rust and premature wear, and anti-cavitation additives prevent the formation of vapor locks at high temperatures and excessive loads.

Specifications

Name	Meaning	Units measurements
Appearance	Clean and transparent yellow color	Visually
Relative density at 20°C, g/ml	1.07	IP 160
Equilibrium boiling point “dry” liquid (ERBP), °C	250 (min.)	ASTM D1120
Equilibrium boiling point “wet” liquid (WET ERBP), °C	155 (min.)	SAE J1703
Kinematic viscosity at 100°C, mm²/s	2.3	ASTM D445
Kinematic viscosity at -40°C, mm²/s	1200 (typical)	IP 71
pH	7.3	SAE J1703

Application area

Container 500 ml

Castrol brake fluid is used in braking systems of commercial and passenger cars, where the use of Dot-4 level products is prescribed.

Tolerances and specifications

• JIS K2233;
• SAE J1703;
• SAE J1704;
• ISO 4925 Class 4;
• FMVSS DOT 4.

Method and conditions of use

Liter packaging

Castrol Dot4 brake fluid is poured into the brake fluid reservoir. For the vast majority of cars, it is located under the hood and is a plastic container with a lid.

In the event that brake fluid needs to be topped up because it has leaked or evaporated, or the brake system has been repaired, the product is poured to the level marked on the reservoir.

There are situations when the fluid must be completely replaced. Lubricant manufacturers recommend changing this product every two years so that its quality is always unsurpassed high level. In this case, the motorist can look at the consumption of a special fluid in the service book or also rely on the level marked on the tank.

An important indicator of brake fluid level is the parking brake icon. If the parking brake lever is lowered and the light is on, this means that there is not enough brake fluid in the system or an air lock has formed.

Advantages and disadvantages

Castrol dot4 has one small drawback - its price is much higher than its Russian counterparts. Also, the product cannot be found at every gas station or small auto store. Due to its low popularity, it is sold only large enterprises for the sale of automotive goods or Castrol specialized stores.

However, Dot 4 Castrol brake fluid has many undeniable advantages, allowing it to remain in a leading position among other foreign products:

• high boiling point;
• versatility of application;
• Can be mixed with other products for DOT 3, DOT 4 and DOT 5.1 brake systems;
• excellent protection against corrosion;
• counteraction to the appearance of vapor locks;
• guarantee of effective braking;
• compliance with international quality standards.

Release forms and articles

• 155BD0 - Castrol Brake Fluid Dot-4, 500ml;
• 157D5A - Castrol Brake Fluid Dot-4, 1l;
• 157D4E - Castrol Brake Fluid Dot-4, 5l.

Conclusion

Plastic canister 5 liters

Castrol Brake Fluid is an excellent brake fluid. The manufacturer was able to increase its boiling point. Many additives have been added to the technical fluid to protect the brake system and improve the performance of the product.

All engineering solutions are reflected in the price. The German product will cost more domestic analogues approximately 3-4 times. Deciding whether to overpay for an imported brand is a matter for each individual motorist. On the one hand, all Dot-4 brake fluids must be made according to the same standard, and on the other hand, save on brakes great desire No.

Video

Castrol Brake Fluid DOT4

First, let's figure out what brake fluid is needed for?

Brake fluid is used in the hydraulic brake drive system, which is located in absolutely all modern cars. The main advantages of the hydraulic drive are the response speed, higher useful action, simplicity of design.

So, when we press the brake pedal, a large frictional force arises between the disc and the pads, leading to heating of the brake elements, which transfer their heat to the fluid in the brake system, as a result of which it can simply boil and lead to system malfunctions.

To avoid these problems, a special liquid is used, which comes in several types.

There are “dry” and “wet” liquids:

• “Dry” liquid, as the name implies, contains less water.
• “Moisturized” - the proportion of water is about 3%. Moreover, these types of brake fluid are divided into four more groups: DOT 3, 4, 5 and DOT 5.1.

In this article we will talk about DOT 4 brake fluid, as it is the most popular filler for modern brake systems.

I think many people here will have a question: what is DOT and why four?

The classification was created in America. The abbreviation stands for “Department of Transport”, and the number “4” indicates that the substance contains elements that bind water condensate.

It is produced chemically and consists of a combination of boric acid and esters.

On video, brake fluid Dot 4, which is better:

Differences

DOT 4 differs from the previous type (3) by the presence in the composition chemical elements capable of binding water entering the brake system from external environment during operation.

Today there are more modern views liquids, for example DOT 5.1, which has a higher boiling point and lower viscosity at very negative temperatures, which leads to stable operation under more severe operating conditions.

Despite best characteristics DOT 5.1 remains less popular view, since 4 successfully copes with the operating conditions of most motorists and has a lower cost.

5.1 is usually used in sports cars that experience high overloads.

DOT 4 and DOT 5.1 fluids are interchangeable, unlike 5, which is silicone-based. As for the compatibility of other fluids, most manufacturers do not recommend mixing them, but in emergency situations you can add a higher class brake fluid (add DOT 4 to DOT 3), but not vice versa.

Adding a lower grade of fluid may cause the fluids to clot and jam the entire system.

But no matter what series of “brake guards” you choose, it is important to know that there must be high-quality tires on the wheels, but how to choose them and which one to choose specifically, for example, can be understood by reading this article.

Price

Today, the price of a brake fluid depends on its manufacturer and ranges from 150 to 1,500 rubles per liter. When purchasing, you need to pay attention to four main indicators:

• viscosity at low temperatures is an important indicator in Russian operating conditions;
• what is the boiling point (the higher the better), the average boiling point is about 230 degrees;
• its lubricating properties;
• whether the brake system protects from corrosion - this indicator, like lubricating qualities, affects the service life of the brake system.

For those who want to know how and how to choose it correctly, it is worth reading the contents of this article.

You may also be interested in knowing whether antifreeze can be mixed or not. For information, please go to

Popular manufacturers

Here are the five most popular manufacturers:

5. Alaska 4 from the manufacturer Tektron LLC - this is the best combination of quality and price, estimated cost 140 rubles per 0.5 liter.

It will also be interesting to know which antifreeze should be used, green or red. All information is detailed in this

When purchasing “brake fluid” for the system, you should definitely pay attention to the packaging and its integrity, since the mixture has hygroscopic properties. It is worth choosing a product with a sealed neck and tamper-evident protection.