One of the important for normal operation car fluids - brake. About why this fluid is needed, how often it needs to be replaced, and which brake fluids to use for optimal performance brake system machines - in our today's article.
The role of brake fluid in the "organism" of the car
The braking system responsible for the timely stop of the car and therefore playing important role for the safety of car passengers, can not work without brake fluid(TK). It is she who performs main function brake system - transmits through hydraulic drive the force from pressing the brake pedal to the brake mechanisms of the wheels - pads and discs, as a result of which the car stops. Therefore, even in driving schools, novice motorists are strongly advised to periodically check the levels of four service fluids: , glass cleaner and brake fluid, on which the optimal operation cars.
Composition and properties of brake fluids
The basis of the chemical composition of most brake fluids is polyglycol (up to 98%), less often manufacturers use silicone (up to 93%). In brake fluids used on Soviet cars, the base was mineral (castor oil with alcohol in a ratio of 1: 1). Use these liquids for modern cars not recommended due to their increased kinetic viscosity (thickens at -20°C) and low boiling point (at least 150°C).
The remaining percentages in polyglycol and silicone TK are represented by various additives that improve the characteristics of the brake fluid base and perform a number of useful features such as protecting the surfaces of the working mechanisms of the brake system or preventing the oxidation of TK as a result of exposure to high temperatures.
It was not in vain that we dwelled in detail on the chemical composition of brake fluids used in cars, since many motorists are interested in the question - “is it possible to mix TK with different chemical bases?”. We answer: mineral liquids for the brake system, it is strongly not recommended to mix with polyglycol and silicone. From the interaction of the mineral and synthetic bases of these fluids, castor oil clots can form, which clog the lines of the brake system, and this is fraught with malfunctions of the brake system. If you mix mineral and polyglycol TK, then this "hellish mixture" will be absorbed into the surface of the rubber cuffs of the hydraulic brake parts, which will lead to their swelling and loss of sealing.
Polyglycol TK, although they have a similar chemical composition, and can be interchanged with and, but mixing them in one brake system is still not recommended. The fact is that each manufacturer of technical specifications can change the composition of additives at its discretion, and mixing them can lead to a deterioration in the main performance characteristics. working fluid- viscosity, boiling point, hygroscopicity (ability to absorb water) or lubricating properties.
Silicone brake fluids it is forbidden to mix with mineral and polyglycol, since as a result the working environment is clogged with precipitated chemicals, which will lead to clogging of the brake lines and failure of the brake cylinder units.
Classification of brake fluids
Today, in most countries of the world there are uniform standards for brake fluids, known as DOT (after the name of the department that developed them - the Department of Transportation - the United States Department of Transportation) - this marking can often be found on brake fluid packages. It means that the product is manufactured in accordance with FMVSS No. trucks depending on the specifications these vehicles. In addition to the American standard, brake fluids are labeled in accordance with the standards adopted in a number of European and Asian countries (ISO 4925, SAE J 1703 and others).
But they all classify brake fluids according to two parameters - their kinematic viscosity and boiling point. The first is responsible for the ability of the working fluid to circulate in the line of the brake system (hydraulic drive, tubes) at extreme operating temperatures: from -40 to +100 degrees Celsius. The second is for preventing the formation of a steam “plug”, which forms at high temperatures and can lead to the brake pedal not working in right moment. When classifying HP by boiling point, two of its states are distinguished - the boiling point of a liquid without water impurities (“dry” HP) and the boiling point of a liquid containing up to 3.5% water (“wetted” HP). The "dry" boiling point of the brake fluid is determined by the new, freshly filled working fluid, which did not have time to "collect" water and therefore has high operational characteristics. The “moistened” boiling point of TK refers to a working fluid that has been in operation for 2-3 years and contains a certain amount of moisture in its composition. Read more about this in the Brake Fluid Lifespan section. Depending on these parameters, all brake fluids are divided into four classes.
DOT 3. The “dry” boiling point of this brake fluid is at least 205 °, and the “moist” one is at least 140 °. Kinematic viscosity such TK at +100° - no more than 1.5 mm² / s, and at -40 - at least 1500 mm² / s. The color of this brake fluid is light yellow. Application: designed for use in cars, maximum speed movement of which is not more than 160 km / h, in the brake system of which disc (on the front axle) and drum (on rear axle) brakes.
DOT-3
DOT 4. The "dry" boiling point of this brake fluid is at least 230°, and the "wetted" one is at least 155°. The kinematic viscosity of such a TK at +100° is no more than 1.5 mm² / s, and at -40 - at least 1800 mm² / s. The color of this brake fluid is yellow. Application: Designed for use in vehicles, the maximum speed of which is up to 220 km / h. In the braking system of such cars, disc (ventilated) brakes are installed.
DOT 5. The “dry” boiling point of this brake fluid is at least 260 °, and the “wetted” one is at least 180 °. The kinematic viscosity of such a TZ at +100° is no more than 1.5 mm² / s, and at -40 - at least 900 mm² / s. The color of this brake fluid is dark red. Unlike the technical specifications mentioned above, DOT 5 is based on silicone, not polyglycol. Application: designed for use on special vehicles operating in conditions of extreme temperatures for brake systems, and therefore on normal cars not used.
The "dry" boiling point of this brake fluid is at least 270°, and the "wetted" boiling point is at least 190°. The kinematic viscosity of such a TZ at +100° is no more than 1.5 mm² / s, and at -40 - at least 900 mm² / s. The color of this brake fluid is light brown. Application: intended for use in braking systems of sports racing cars, in which the temperatures of working fluids reach critical values.
Pros and cons of brake fluids
All of the above brake fluids have their advantages and disadvantages. For convenience, we list them in the table below:
| TK class | Advantages | Flaws |
| DOT 3 |
|
|
| DOT 4 |
|
|
| DOT 5 |
|
|
| DOT 5.1 |
|
|
When to change brake fluid?
The life of the brake fluid directly depends on its chemical composition.
Mineral TK by virtue of its chemical characteristics(low hygroscopicity, good lubricating properties) has a fairly long service life (up to 10 years). But when water enters the liquid, for example, in the event of depressurization of the brake system, its properties change (the boiling point drops, the viscosity rises), and it can no longer perform its functions, which can lead to brake failure. Periodic inspection (once a year) of the brake system and the condition of the fluid, which can be determined in the laboratory, is recommended.
Polyglycol TK has a medium or high degree of hygroscopicity, and therefore its condition should be checked twice a year. It is possible to assess the condition of polyglycol TK visually: if the liquid has darkened or precipitation is noticeable in it, then it is necessary to conduct it complete replacement. In a year, such a TZ is able to absorb up to 3% moisture. If this indicator exceeds 8%, then the boiling point of the brake fluid may drop to 100 °, which will lead to boiling of the fuel oil and failure of the entire brake system. Automotive manufacturers It is recommended to change the brake fluid based on polyglycols every 40 thousand kilometers or every 2-3 years. Usually such brake fluid is completely changed during the installation of new external brake mechanisms (pads and discs).
Silicone TK is distinguished by its durability of operation, since its chemical composition is more resistant to external influences (moisture ingress). As a rule, the replacement of silicone brake fluids is carried out after 10-15 years from the date of filling into the brake system.
From this article you will learn - why do we need brake fluid for a car, its properties. We will tell you when to change and which one to fill.
The function of the brake fluid is to carry out the work of the hydraulic drive, i.e. transfer pressure from the master brake cylinder (subordinate to the brake pedal) to the wheel brake cylinders, which will brake the movement with the help of shoes. But imagine what could happen if these functions were not performed well enough and the car slowed down much later?
No, it's better not to imagine SUCH ... Why is the quality of the brake fluid so important and what should it be? Understanding...
Requirements
- Work in a wide temperature range: -30 to +150 ( working temperature in brake cylinders during intensive braking);
- Non-aggressiveness: both to rubber sealing parts of the hydraulic system, and to metals;
- High lubricity - for internal surfaces brake cylinders;
- Stability of properties: their independence from operating conditions.
1. Mineral. It is characterized by low aggressiveness to rubber, good lubricating properties and low price. Disadvantages: very viscous at temperatures below -20, low boiling point. It is widely used only on older machines due to its neutrality to rubber gaskets, it is not used in modern ones.
2. Synthetic from a mixture of polyglycols and ethers. The most common base with high operational properties. Main disadvantage- high hygroscopicity - i.e. ability to absorb moisture, which significantly worsens the main parameters of the brake fluid and causes corrosion of the metal parts of the hydraulic drive.
3. Synthetic silicone. The most modern and completely non-hygroscopic. Used in rare cases due to poor compatibility with standard rubber parts, complete incompatibility with the previous two types, increased requirements for the quality of pumping to completely remove air from the system, high prices.
Basic properties
Boiling Point: The higher the better. When a liquid boils, vapor is released from it, which, unlike a liquid, is compressed. In practice, this will lead to "failure" of the pedal and lack of braking. It manifests itself with frequent braking, when the heat from friction does not have time to be removed from the brake system and general temperature grows in it (for example, when descending from a high mountain in summer). Really dangerous and unpredictable phenomenon.Viscosity stability at low and high temperatures. Critical cases - complete thickening at low temperatures or high fluidity at elevated temperatures (lack of lubrication, likelihood of leakage). In standards, it is measured from +100 and -40.
How often to change?
Brake fluid absorbs moisture from the air and condensation due to constantly changing operating temperatures. This leads to its thickening in winter, poor lubrication in summer and constant corrosion of the metal of the hydraulic system. And the worst thing is that only 3% of the water dissolved in it will reduce the temperature of its boiling by about 70 degrees! This main reason that it is recommended to change it every 2-3 years.For example, for 3 years of operation of the machine, an average of about 3.5 percent of water accumulates in the "brake". When compared with “dry” without water, the boiling point decreases from the standard 250 degrees to 160-180 ° C. The difference is huge. A diluted liquid boils before a "dry" one. In real operation, the brake pedal becomes a stake, but the car does not slow down.
During operation, the brake fluid may change color. Due to strong heat, corrosion, oxidation, interaction with rubber parts. Color change does not affect operation. It is difficult to objectively check the condition, the liquid in the system practically does not mix. Accordingly, it will have more water in the tank, and in the working cylinders, due to the constant exposure to high temperatures, its properties will be different.
By the way, for this reason, the addition of a fresh “brake” will have practically no effect on the properties of the system as a whole.
What should be filled in? The most important rule: use the manufacturer's requirements, because. they designed the braking system to specific parameters. The manual also specifies replacement intervals. For example, buy DOT fluids 5.1 or DOT 6 is not needed if you do not know if it is compatible. If you don’t know what was previously filled in, it’s better to completely replace the “brake”.
- What to do if you need to bleed the brakes without an assistant?
How to top up? You need to know what is in the tank under the hood. We buy the appropriate one and top it up. You should monitor the level so that it is at the level of the “max” mark. If it has dropped to the “min” level, then you should definitely top it up. As a rule, top up with working system brakes should be done no more than once a year.
How much to replace? Typically, the brake system contains a small amount of "brake". You can clarify in the instruction manual, which indicates the total volume in the system. For a complete replacement, you need about a liter.
Modern brake fluids are quite technologically advanced, they withstand high temperatures, as well as high pressure in the brake system of a modern car. They are not compressible and therefore they are used in the braking system of a car, that is, it will not work to compress - as we say, gas or air. That is why the car's system is liquid, it has proven its reliability (to be fair, it should be noted that there are also pneumatic options). BUT still the hydraulic version has small cons- it can leak out, for example, when it breaks brake hose but you have to go! But what if you don’t have exactly the same composition as you have (the original from the dealer is flooded)? Then a fair question arises - is it possible to mix brake fluid various manufacturers and different classes let's say pour DOT3 into DOT4 - what will happen? As usual, the article will have an extensive + video version at the end, so read on - watch ...
It is worth noting that the brake fluid has gone through a long period of evolution, as usual, everything originated from mineral compounds, then glycolic (now the most commonly used), then silicone (many write the future for them, but I do not quite agree) appeared. So what caused such a leap in development? YES, everything is simple, cars are getting faster, the speeds are prohibitive, and therefore mineral mixtures which were previously corny do not meet these requirements.
Dry and Wet Mix
At the very beginning, I want to talk about the hygroscopicity of brake fluid (for those who do not know, this is the ability to absorb moisture from environment). That is why it is mandatory on average after 2 - 4 years, it all depends on the class (more on that below).
So when you just opened a sealed jar (which had no contact with the surrounding air), and want to pour into the main tank, then such a composition will be called - DRY because there is no moisture at all! After all, they just opened.
But if your car or open jar was in contact with air (the jar could lie open on the shelf for a couple of years). That liquid has already absorbed a large percentage of moisture! Moreover, only 3.5% is enough so that it can no longer be used in the brake system! Such a mixture is called - HUMIDIFIED (it is banal that it contains water)!
Classification byDOT
To begin with, what is DOT in general - if you decipher it, it turns out that the Department Of Transportation (Or the Department of Transportation) is located in the jurisdiction of the United States. So this department decided to distinguish between different compositions by class - as a result, DOT1 appeared, and then others.
DOT1- DOT2 - these are the very first brake fluids, they were based on mineral substances, now they are practically not used, so we will not bother with them, although I will note them for general development. They were used on low-speed cars, speeds up to about 40 - 60 km / h, under heavy loads they could boil quickly enough. Because of this, they quickly lost their characteristics.
Now a small remark - ask, why could it boil? Yes, everything is simple when the car slows down, and the slope is protracted, wheel disks can heat up to 350 - 400 degrees Celsius. Part of the heat is transferred to the calipers, and from them to the “brake” itself. Mineral began to boil already at 140 degrees.
DOT3 - this is the third class, it was kind of innovative. In its composition, a glycol base has already been used. Boiling temperature dry liquid - 230, and wet - 140 degrees .
DOT4 - the fourth grade, do not believe the third was not enough, especially in a state of moisture. The basis is again glycols. The compositions have been slightly improved, and now the characteristics 240 and 155 respectively . It is worth noting for most passenger cars on this moment this is enough, but there are cars with powerful motors, heavy bodies and exorbitant speeds.
- for them the next class (why with a dot you will understand later). There is also a glycol component in the base. BUT the temperature threshold is again increased up to 260 and 180 degrees actually . However, these compounds are much more expensive, so they are rarely used on budget cars.
As you understand it, so to speak, is the “glycol branch” of development. Such compositions have many advantages, because not only boiling is important for us, but also lubrication with inside- these are pistons, seals, cylinders, etc. (it should be noted that seals work with glycols very well and for a long time). Also, these brake fluids are quite stable. That is, they do not have any deviations in the characteristics.
Of the minuses - replacement every 2 - 3 years, because hygroscopicity is very high level. It should be noted that this is a really "fat" minus.
DOT5 – fifth generation, there is more ABS In fact, they are very similar. In general, they were made as something revolutionary, they were supposed to supplant the old compositions and become the leader. The thing is that silicones are the basis. Temperature characteristics approximately the same - it's 260 for dry and 180 for wet . But a big plus is hygroscopicity here it is not as big as that of opponents! You can operate 4 - 5 years without fear, yet silicone does not absorb moisture so much.
It seems to be the perfect long-term composition. But it turned out that there are also significant disadvantages.
Silicones do not have such lubricating properties as the opponent. Because of this, the wear of seals, cylinders, pistons occurs much faster. That is why the manufacturers returned back to the previous formula, and the “5.1” generation appeared. The introduction was long, but it is necessary to understand whether it is possible to mix or not
What happens if you mix brake fluids
Now the fun part, that's what we're here for. Whether it can be mixed or not. As we understood, there are two main subspecies, we will conditionally call them:
GLYCOLS are DOT3, DOT4, . They can be mixed in any ratio, if you want they are interchangeable, nothing bad will happen! HOWEVER, THERE IS ONE BUT (as usual). If we say that DOT3 is poured into the most perfect "brake" DOT5.1, then the final mixture will turn out to be underestimated. That is, the temperature threshold will fall to lower level. And now we think that the fifth generation "5.1" - IS EXPENSIVE, "3" - IS MUCH CHEAPER. Who in their right mind would mix them up?
It's rather emergency measure, let's say you left for another city, the caliper leaked, you restored it, but your DOT5.1 was not there, you can pour DOT4, but upon arrival it is advisable to replace everything with desired level. After all, the manufacturer did not just flood the fifth generation, which means there were reasons for this, for example, powerful or heavy car, when braking great effort to stop it, respectively, a large warm-up.
SILICONES - DOT5 and ABS they CANNOT be filled with other classes DOT3, DOT4, DOT5.1 - THEY DO NOT MIX! Glycol and silicone are not the same formulations! EVEN DOT5 and DOT5.1/ABS are not recommended for mixing, although they have same base, but various characteristics and properties.
Mix from different manufacturers
And finally, is it possible to mix different manufacturers? YES OF COURSE YOU CAN, why not? After all, there is RIGID standardization, so DOT4 from completely different companies is interchangeable, because they must have the same basis and temperature characteristics.
The liquid is not compressible. This law is known to us high school, and it is on it that the operation of the brake system of a modern car is based. What happens if there are exceptions to the law? You say it doesn't happen. Sometimes the owner of the car creates them with his own hands, violating the frequency of replacing the brake fluid. Consider typical faults, which may arise due to its untimely replacement and non-compliance with the rules for performing this operation.
Why change brake fluid? She works in enclosed space, and its properties cannot be changed.
Brake fluid works in a space that can be called closed rather conditionally. The system has compensation holes that let air into it when you press the pedal, and release it when it is reversed. As a result, the brake fluid, which contains, among other substances, various alcohols, absorbs moisture from the surrounding air (the brake fluid is hygroscopic). In addition, irreversible chemical reactions, and the additives that make up the brake fluid lose their properties over time. Therefore, its composition changes over time, and quite significantly.
Modern brake fluids can be mixed in any proportion.
Indeed, brake fluids can be mixed, but not all and not with all! Only those of them that meet the same standards are mixed. But it should be noted that liquids from different manufacturers, as a rule, have different additive formulations, and sometimes they are made on a different basis. In addition, you cannot always be sure of the brand of fluid poured into the brake system. Therefore, it is still better not to mix brake fluids, as if they are incompatible, the brakes may fail.
Modern vehicles can use any brake fluid that meets DOT-4 standards.
This is a misconception. A number of car manufacturers allow the use of specially designed fluids in brake systems. Some of them are based on mineral basis, so it is strictly forbidden to mix them with glycol fluids. The use of glycol fluids in the brake systems of vehicles designed for mineral water is also unacceptable. Leading manufacturers of brake fluids usually warn consumers directly about this.
Therefore, be sure to follow the requirements of the car manufacturer, and carefully read the description of a particular fluid that you want to purchase. It usually lists restrictions on the use of the product, if any.
Even if the brake fluid absorbs water, it is also incompressible. Therefore, there will be no harm.
In this situation, the problem is not that the water can compress. Since the boiling point of water is only 100C, the more it is in the brake fluid, the lower the boiling point. Considering that when braking brake mechanisms get very hot, such a cocktail can boil, vapor locks form in the liquid and the brakes become weak. In other words, the pedal goes to the floor!. Considering that this phenomenon occurs precisely when it is necessary to slow down strongly and often, the danger is obvious. That is why you should strictly adhere to the recommendations for the frequency of replacing the brake fluid.
The liquid darkens due to the fact that it contains detergent additives, so a change in color is not a sign that a replacement is needed.
Unfortunately, this statement is only true for engine oils. In brake fluids, discoloration is a sign of contamination with wear products and dust particles. If the liquid is not changed for a very long time, other irreversible changes occur in it, it becomes viscous and more like diluted bitumen. Dirt particles can cause the brake cylinders to seize and cause brake failure. There are also frequent cases of the appearance of various varnish-like deposits on internal surfaces parts of the brake system. Therefore, the darkened liquid must be changed without waiting for the expiration of the established period.
If you change the brake fluid on time, air cannot appear in the system.
The fluid must be changed not only in a timely manner, but also correctly. There is such an operation - pumping the brake system. In the process of pumping the brakes, the old brake fluid is replaced with a new one, without air entering. To pump the brakes, you will need a small supply of fluid, so you need to buy it about one and a half times more than the capacity of the system. A sign of air entering the system is a feeling soft pedal(the brakes are taken from the second or third time). And you need to pump the system until the pedal becomes stiff and stops at the same point in its travel. When performing this operation, it is necessary to follow the recommendations of the vehicle manufacturer, turning Special attention on the sequence of pumping the brake cylinders, since the completeness of removing air from the brake system depends on it.
The type of brake fluid does not affect the speed of the car, so you can fill in any modern fluid.
Brake fluid, of course, does not affect speed, but the speed characteristics of a car may require a different fluid. When moving to high speeds or with frequent braking, brake fluid with a high boiling point is required. Therefore, a number of vehicles require special liquids. For instance, Ford and Rover Group recommend fluids with a boiling point of 260°C for factory filling of the brake system. An example of such a product is Texaco Universal Brake Fluid DOT 4, which specifically states the boiling point value and compliance with the requirements of the above manufacturers. And Texaco Brake Fluid HD, which complies with ISO 4925, FMVSS 116 - DOT 3, 4 and 5.1, SAE J 1703, simply states that it has a high boiling point, both dry and wet. .
Summarize
Use only those brake fluids recommended by the vehicle manufacturer. When purchasing brake fluid, carefully follow the exact specifications for your car, be careful about the recommendations of strangers. Follow recommended fluid change intervals. When buying a used car, it is better to change the brake fluid immediately. You will know exactly what was filled and when. This will avoid guessing whether or not you need to replace it, and avoid problems with the brake system. After changing the fluid, do not forget to bleed the brake system in accordance with the regulations.
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Is it possible to pour tormazuha into a diesel?
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it's dumb to drive with an empty tank, it's better to call a tow truck ...
Every motorist has come across a situation where it is necessary to change or add brake fluid to the system. If you regularly technical inspection service, then there will be no problems in the future. It will be enough just to change specialized fluid following the manufacturer's recommendations. It should be noted that brake fluid is different type, this should not be forgotten. If you fill in the wrong option, then over time there will be trouble.
But there are times when brake damage occurs on the road, far from the location of your garage or service. In this scenario, many drivers simply add fluid to get required level. Due to this, you can get to the place and make a complete replacement of the system. It will be good if the driver is prudent and carries with him enough special fluids and the like. Otherwise, you will have to fill in the first one that comes across, which is sold in the nearest store. And this is quite bad, since you do not know the quality of products and features. Before filling, you should consider whether it is possible to mix the purchased products with those in the brake system. You will try to consecrate a similar question in the article.
Currently, you can find several varieties of brake fluids:
1) DOT - 3. This type of liquid has an oily base and a light brown tint. The boiling point is within 200 degrees Celsius. Recommended for vehicles that are equipped with a drum brake system, such as trucks and similar cars. Everyone knows that during braking, the drum system heats up much less than the disc system;
2) DOT-4. This variety has a transparent color, in which cases a light brown tint. As for the boiling point, it varies within 230 degrees Celsius. It is used in all motorcycles and some cars;
3) DOT-5. Brake fluid has a reddish tint and a boiling point of around 180 degrees Celsius. Recommended for use in sports vehicles and powerful motorcycles. After all, it requires not only good dynamic properties but also an excellent braking system;
4) DOT-5, 1. Has an oil base like all other brake fluids. A small feature is the boiling point, it varies within 260 degrees Celsius. As for the color itself, the brake fluid has a yellowish tint. In fact, this is a slightly improved version when compared with the previous generation.
How often to change fluid?
It is recommended to change the brake fluid at least once every two years, regardless of the car model, as it works in difficult operating conditions - it heats up to high temperatures during frequent braking. The “brake” is also hygroscopic, and over time, moisture accumulates in its composition, from which the boiling point of the TF decreases. If too much moisture accumulates, the fluid will boil when braking, the car's brakes will fail.
You also need to change the brake fluid:
1) when buying a used car - it is not known when the previous owner serviced the vehicle for the last time;
2) when the liquid becomes cloudy or a precipitate appears in it.
The industry has developed special testers that check the hygroscopicity of TJ, an example is the Novitec device. On his front panel There are four indicators:
1) Gut;
2) 1%;
3) 2%;
4) 3%.
When, when checking the brake fluid on the tester, lights up green indicator Gut, this means that the brake fluid meets the requirement of hygroscopicity and does not contain water in its composition. 1% - the condition of the "brake" is satisfactory, 2 and 3% - the fluid must be changed, it is not suitable for further use.
What is brake fluid made of??
Combines all brake fluids, with the exception of DOT-5, their base component is polyethylene glycol. The basis for the creation of DOT-5 is silicone. You should remember that the composition of DOT-5.1 is fundamentally different from DOT-5, which is consonant with it. If there is an emergency, the combination of DOT-3, DOT-4 and DOT-5.1 is permissible, since they have a common base. Even better if they were made by the same manufacturer. At the same time, we must not forget that adding another DOT-3 liquid to the DOT-4 liquid, you thereby lower the boiling point of the first one. If you mix liquids made on different components, that is, silicone and polyethylene glycol, as a result of the reaction between them, a composition is formed that simply is not a brake fluid, which is extremely dangerous for further movement.
Which liquids to mix and which should not:
Based on the foregoing, it is worth remembering that in no case should you:
1) allow mixing a composition such as DOT-5 with any of the above, they are completely incompatible;
2) connect in the brake system of a car with ABS, fluids, one of which is designed for ABS, and the second is not;
3) add a liquid such as DOT-3 to DOT-5.1: the resulting mixture will boil at a lower temperature;
4) the mixing of DOT-4 and DOT-3 threatens the same - a decrease in the boiling point of the resulting mixture.
In case of emergency, it is allowed to add:
1) DOT-4 when DOT-3 is in the system;
2) DOT-5.1 to the main DOT-3;
3) DOT-5.1, when the working composition is DOT-4. The resulting mixture boils at more than high temperature than the original, which, in principle, is allowed.
It is not recommended to interfere with liquids released under different trademarks. Each manufacturer does everything to give their product high quality by adding a variety of additives. It is difficult to predict how these liquids will behave during interaction. Whatever combination of fluids you use, the first thing to do after suddenly topping up brake fluid on the road, reaching your destination, is to completely change the entire mixture in the brake system. If you plan to replace DOT-4 with a newer DOT-5, you will need to flush the brake system in order to eliminate residual fluid.
Flushing the system must be done in the following cases:
1) if one type of “brake” changes to another;
2) in case of turbidity of the brake fluid or precipitation in it;
3) if there is a large amount of moisture in the old liquid.
The principle of washing is as follows:
1) using a syringe, the liquid is pumped out of the tank;
2) the brakes are bled until fresh brake fluid flows out of the fittings;
3) the operation is repeated several times, then the system is filled with a new "brake", the brakes are finally pumped.
Remember, it never hurts to carry a supply of the exact brake fluid that is filled in your car with you, in order to avoid situations where you need to risk and mix different types liquids. After all, it is not always possible to know what this will lead to. It may take a lot of time and Money for recovery.
