The requirements for brake fluid are quite serious - it should not accumulate water (condensate from the air) in itself, and also have a stable viscosity in the range from -60 to +300 degrees. The brake fluid should be neutral to cuffs, rubber bands and metal.
With prolonged or sharp braking, a very strong heating of the brake pads occurs, and this heat is transferred to the caliper piston, thereby the brake fluid can boil, forming vapor plugs in the system, which makes the brake pedal wadded or falls through, and for effective braking, you have to pump up pressure by rapid pressing the brake pedal. This problem is especially common on Gazelles, since the vehicle's braking system is not designed for the weight they are carrying.
Brakes, like engine oils, are different, but they are united by the Dot3 or Dot4 model.
Dot 3 - quite old brake fluid and the only plus, the cost is slightly lower than Dot4 and it can be mixed with DOT4. This fluid can be used in vehicles in which the braking system is not loaded. Replacing such a fluid every 2 years.
Modern cars in our climatic zone use DOT4 and Dot 3 is no longer on sale. More advanced than DOT3, it has several advantages. Increased boiling point, the composition contains additives that absorb moisture and, accordingly, such a liquid freezes less at low temperatures. The cost of 1 liter is about 300 rubles. Replacement of brake fluid DOT4 every 3 years.
Liquid DOT5 they are not used in our climate, since the composition includes silicone, which simply does not mix with water, and condensate that accumulates in some depression simply freezes and blocks the passage of liquid along the line. DOT5 does not mix with DOT4 or DOT3.
Why you need to change the brake fluid.
Condensation gets into any liquid in the car and the brake is no exception. Water reduces the property of the brake fluid, it begins to freeze, boil and such fluid becomes aggressive to metal, forming corrosion on the cylinders or pistons of the calipers. Severe corrosion of the caliper causes brake fluid to leak. Motorists, who save on timely replacement of brake fluid, pay doubly in the future to replace parts of the brake system, and this is at best.
How to change brake fluid
A brake fluid change can be combined with a seasonal wheel change. You will need an 8 or 10 wrench and a short 5mm tube and a liter of Dot4. In order not to break the lines the pumping nozzle, the connection points are treated with penetrating grease and then we unscrew the socket head with a tight fit, as they unscrewed, you can also drain with an open-end wrench
It is enough to pump out the old liquid from the tank with a syringe and fill in a new one. Then, at the far wheel, unscrew the bleed fitting and drain the liquid about 30 milliliters and so on for each wheel. The last one should be the wheel that is closest to the brake fluid reservoir.
Volume brake fluid reservoir 0.5-0.8 liters, depending on the car brand.
If the brake fluid is leaking - in fact, there is nothing to worry about, as the brake pads wear out and the brake calipers move out more and the fluid level decreases. When installing new pads, the level will return to normal. As a rule, when the brake level is low, the parking brake lamp flashes.
Replacing the brake fluid by replacement
Some car owners believe that a simple brake replacement with replacement takes place, as the fluids mix and the brake will gradually push out all the water, but this is not the case. Water is heavier than brake fluid and if it is already present in the tank, then there is even more of it in the brake caliper and it can only be displaced by a complete replacement, unscrew the pumping union and drained. Otherwise, the liquid does not change.
Article rating
The brake pedal usually falls into the floor at the most inopportune moment. When brakes are especially needed
Science
Real stories about how they managed to get out of such a difficult situation are almost not heard among the drivers: not being able to stop, it is difficult to survive on a mountain serpentine or in front of an obstacle that "rolls" at a speed of two hundred ... And those who are lucky often talk about miracle: absolutely serviceable brakes with worn-out friction surfaces (pads, discs, drums) failed. The pedal "suddenly" failed, and after a while "recovered". It was really possible to believe in evil fate, if not for one detail, more precisely - liquid. Brake, of course.
In the brakes, it plays no less role than any other part of the system. Their performance depends on its condition, and hence the lives of people.
When heated, any liquid begins to boil, that is, it moves from one state of aggregation to another. Gas, unlike liquid, is easily compressed. There is plenty of heat in the brakes: with frequent harsh braking, the brake pads heat up to almost a thousand degrees. When the fluid in the hydraulic brake actuator boils, its vapors (i.e., the gas phase) are easily compressed, the pedal goes to the floor. This problem was known at the dawn of motoring and since then, with the growth of power and speed, it has been regularly successfully solved. Each time, chemists find a new compound that does not freeze at low temperatures and does not boil at relatively high temperatures.
The last three generations of hydraulic brake fluid (DOT-3, DOT-4 and DOT-5.1) are produced on a glycol basis. They are all good, one problem: they actively absorb water from the air. The boiling point of the liquid gradually decreases, reaching the maximum permissible (150 ° C). Almost all car manufacturers recommend replacing the GTZ every two years or 60 thousand kilometers. Its further use is fraught with danger.
"Thrifty" car owners justify themselves by the fact that they do not drive fast, and that they do not go to the mountains at all. But the water in the hydraulic drive not only boils, but also freezes and also causes corrosion. Most likely, it will not come to the complete freezing of the liquid, but the braking efficiency may deteriorate. And the most unpleasant thing is that "wet" brake fluid loses the stability of its physical properties, which affects the stability of the brakes. At the beginning of the trip, the pedal “stands like a stake”, and after several vigorous braking, it suddenly becomes “sluggish”. There is no need to talk about cost savings, even if an accident was avoided.
Brake pipes today are mostly made of steel. With the old liquid, despite the presence of a protective coating, they rust not only on the outside, but also on the inside. And who knows if corrosion centers will appear soon? Moreover, designers, believing that their recommendations are unconditionally followed, often use materials that are incompatible in aggressive environments. A typical example is aluminum pistons in cast iron brake cylinders. A little moisture, and the pistons became acidic, lost their mobility due to corrosion. A bottle of fresh brake fluid costs no more than one cylinder. How many of them are there by car? Let's add pipes and work. Are you so rich that you can afford not to change your fluid for years?
On practice
We brought a small red suitcase with the TRW logo from Frankfurt from the Automechanika-2008 exhibition. It contains an electronic device for testing brake fluid (YMB 214). The instruction is in 19 languages, but without Russian. In the near future, the device will be available in Moscow, and then a Russian page will appear. However, you can do without it. Working with the device basically boils down to three steps: correctly connect the clamps to the battery, put the “trunk” of the device into the tank with liquid and read the readings on the scale. Let's try to find out how safe the cars around us are.
Fight test
The cavalry assault with horrifying conclusions failed. It can be seen that the target for the attack was poorly chosen. The motor transport company, which is part of the largest and oldest communications company since Soviet times, we admit, was a pleasant surprise. The head of the workshop, having examined the outlandish device, sighed: “Sometimes they don’t give us money for spare parts either. We orient ourselves by the color of the brake. " Our conclusion: there are no color blind people in the carpool.
All tested cars were filled with conditional brake fluid. The temperature of all samples ranged from 180 to 210 ° C. Recall that the critical values \u200b\u200bare 140 ° C for DOT-3, 150 ° C for DOT-4, and 180 ° C for DOT-5. GTZh DOT-4 is used in Gazelle, Volga and Quartet, which make up the majority of the park. Excellent result!
We go out into the street, right in front of the editorial office. The one-year-old Sobol takes the lead: 253 ° С. However, lower values \u200b\u200bwould be somewhat scandalous. The Volvo 940, released in the last century, was approached not without sarcasm, and unsuccessful attempts to unscrew the cap of the brake master cylinder reservoir caused frank laughter from those present. It is not surprising that the cork did not go without a rag: for two years of owning a car, its owner did not even check the liquid level. The result was shocking - 193 ° С for the liquid, which served much more than expected! And this is in St. Petersburg, "famous" for its swamp climate and the corresponding air humidity.
The third day of testing was carried out in a garage cooperative. And not in vain. Only here cars with "criminal" brake fluid were found. The worst result (127 ° C) was recorded in the fifteen-year-old "Niva", abandoned by the owner in the garage as unnecessary a couple of years ago. During its operation, the owner changed the complete calipers and regularly added brake fluid, but when he did it, he could not remember. In several machines, the boiling point of the liquid was close to critical. But it was not possible to identify obvious patterns: both old domestic cars and foreign cars “sinned”.
Our test does not claim to be scientific or completely objective. We were able to persuade less than a hundred car owners to check the GTZ. A negative result was revealed only in isolated cases. More accurate data could be given by service station specialists armed with a similar tester. Our observations only confirm the fact that the problem really exists, although, perhaps, it is somewhat exaggerated. At least in terms of service life.
However, in the absence of a device and the skill of "eye diagnosis", the recommendations of the factory management should not be neglected.
TRW YMB 214
The device is designed specifically for the needs of service companies involved in the repair and maintenance of brakes. It allows you to determine the condition of the used brake fluid in the reservoir of the master brake cylinder. Power supply - from the car battery (12 V).
The use of the device makes it possible to replace the GTZh on time, preventing the development of internal corrosion and failure of the brakes, both due to liquid boiling and due to malfunction of cylinders and pipelines. In the process of replacing the fluid, other defects can be identified, the elimination of which is useful to the owner who receives a guaranteed serviceable car from the repair, and is beneficial to the service, since it gives additional workload to the workers.
Car for pumping
Replacing brake fluid is not much different from bleeding the brakes. Hoses are put on all pumping fittings, the other ends of which are lowered into transparent containers. The fittings open all at the same time. We squeeze out the old fluid from the system, sharply pressing and smoothly releasing the brake pedal. Pour the spilled liquid into another container. It can be useful for loosening tight, rusty nuts.
Put the containers under the hoses again, pour fresh liquid into the tank and swing the pedal in the same rhythm until the liquid appears in the vessels. We wrap all the fittings and bleed the brakes in the sequence indicated in the instruction manual. It is better not to use fresh drained liquid for its intended purpose.
A bike with a commentary
In the seventies, such a bike went among the Leningrad taxi drivers. The taxi driver drove to the full, hurrying with the passenger to the airport. I wanted to slip into yellow (after green), but the car in front stopped. The taxi driver on the brakes, the pedal fails. Impact, accident.
The taxi driver sat in the car, holding the pedal "on the floor", for two hours, until the traffic police inspector arrived. Only after the fact of the failure of the brakes was recorded in the protocol, he removed from the pedal, not numb, but a stiff leg. The next time the brakes were pressed, they worked normally. An incomprehensible factory defect was recognized as the cause of the accident. But most likely it was in the old or low-quality brake fluid. The resourceful (and patient) driver escaped punishment. The taxi company paid for the wrecked car. Whether the claim was made to GAZ, history is silent.
It makes no sense to repeat the "feat of a taxi driver" on your car: the owner himself is responsible for its technical condition. The only exception is a completely new car. There is a chance to bring the manufacturer to justice for a factory defect.
It is another matter if you are a hired driver and you have been driving a car that had an accident recently. Then, perhaps, it will be possible to transfer the arrows to the owner. But in any case, it is cheaper and less troublesome to replace the liquid on time.
Brake fluid is a type of hydraulic fluid that is used in hydraulic brake systems and hydraulic clutch systems on cars, motorcycles, light trucks, and bicycles. The fluid is used to transmit pressure and to enhance the braking force.
General information about brake fluid
The principle of operation of the brake fluid is its low compressibility. Molecules do not have an internal void, therefore, when compressed, the volume of the liquid does not decrease, and the pressure quickly spreads to the entire volume.
Brake fluid composition
There are different types of brake fluid, but it is usually made from a low-viscosity solvent such as alcohol and a viscous non-volatile substance such as glycerin.
On the basis of polyethylene glycol, brake fluid is produced under the brands DOT 3, DOT 4 and DOT 5.1.
Silicone-based - silicone-organic polymer products DOT 5 grade.
For vehicles with anti-lock braking system, DOT 5.1 / ABS braking fluids based on silicone and glycols can be used. About brake fluids wiki: link.
Characteristics and properties of brake fluid
In order for the braking system to function properly, the brake fluid must have certain characteristics and meet quality standards.
Boiling temperature... New brake fluid does not contain moisture, so its boiling point is within acceptable limits. But over time, moisture from the ambient air enters the fluid, usually 1-2% per year of the total volume, but the characteristics of the brake fluid begin to change.
During braking, the working fluid heats up to very high temperatures due to friction. At this point, it is very important that the brake fluid does not boil, as in this case moisture evaporates from the fluid in the form of vapor. And steam is dangerous in that it is easily compressed and during the next braking the pressure on the brakes will be less, since part of the volume will be taken away by the compressed steam.
The boiling point of brake fluid directly depends on the amount of water in it. The more water, the lower the boiling point and the greater the chance of "losing" the brakes.
Hygroscopicity... Some brands of "brake" have minimal hygroscopicity (moisture absorption), for example, DOT 5 and can maintain the required characteristics throughout the entire service life. But the most common brands DOT 3, DOT 4 and DOT 5.1 are gradually losing their properties due to the increasing amount of moisture in them.
Viscosity... How the brake fluid is pumped throughout the system will depend on this characteristic. And it should pump well at -30 degrees Celsius and at 200 degrees, during braking.
If the fluid freezes completely or in places, it will block the brakes. Too thick fluid will be difficult to pump throughout the system, which will lead to either poor braking or different effort on different wheels. And too liquid will lead to leaks.
Corrosion protection... The brake fluid itself acts as a corrosion protection inside the brake system. In this case, protection must be provided even with small amounts of moisture inside the system.
Corrosion protection is ensured by special additives. They also provide protection for the sealing elements.
Compressibility... Ideally, the brake fluid should not compress at all, but there are certain tolerances for this characteristic. The main thing is that the liquid works equally well under different temperature conditions.
| "Dry" boiling point, ° C | "Wet" boiling point (water 3.5%), ° C | Viscosity, mm 2 / s |
Main components | |
| DOT 2 | 190 | 140 | — | Castor oil / alcohol |
| DOT 3 | 205 | 140 | 1500 | Glycol |
| DOT 4 | 230 | 155 | 1800 | Glycol / Boric acid |
| LHM + | 249 | 249 | 1200 | Mineral oil |
| DOT 5 | 260 | 180 | 900 | Silicone |
| DOT 5.1 | 260 | 180 | 900 | Glycol / Boric acid |
Brake fluid compatibility
For topping up, you can use a liquid from the same manufacturer, but subject to the principles:
- you can only add liquid with a higher rating figure, that is, DOT 4 can be poured into DOT 4, and DOT 5.1 can be poured into DOT 4.
- Do not mix DOT 5 with other brands - DOT 3, DOT 4, DOT 5.1.
- Mineral (eg LHM +) and glycolic fluids must not be mixed.
If you break the rules, this will lead to a serious change in the characteristics of the liquid for the worse.
How often to change the brake fluid
The question of when to change the brake fluid can be answered unequivocally: once every two years or after 40,000 mileage. These are general guidelines.
If the car is operated in harsh conditions, then it is necessary to change the brake fluid more often.
Regular topping up cannot fully compensate for changes in the properties of the liquid - the boiling point drops, the chemical composition changes, and anti-corrosion additives work worse. You can use the refilling method only when carrying out repairs or in the event of a leak, when you just need to drive to the service station or garage.
You can determine an unusable brake fluid:
- With a complete analysis using special equipment.
- "By eye" - the old liquid is dark in color, while the new one is translucent.
- Using a device that determines the amount of moisture in a liquid. If less than 3.5 percent, then you can still ride.
It is necessary to fill in the brake fluid into the expansion tank of the brake system. It is usually located above the brake master cylinder and serves to compensate for brake fluid when it heats up and to prevent air from entering the system.
The fluid level in the reservoir should be between the "MIN" and "MAX" marks. In modern cars, there is a float with a sensor that will notify the driver that the fluid level in the reservoir has dropped below the minimum mark.
How to change brake fluid
It is best to do this at a specialized service station. Most modern cars have an ABS system, and this leaves its mark on the procedure. Special equipment is required to pump the system with new fluid.
If you are told that you can perform a brake fluid change without bleeding without special equipment, then do not listen to these tips. Yes, on some wheels the pressure from the reservoir can push the system through, but this will not work on all. As a result, air or old fluid will remain in the system. At the service station, the fluid is replaced under pressure, so subsequent pumping is not required.
The replacement procedure itself is as follows. New liquid is poured into the empty expansion tank of the cooling system, after which a pumping occurs on each line, during which the new liquid displaces the old one.
The average brake fluid volume is 0.75 to 1.3 liters.
A clear change of brake fluid without special equipment is described in the video below:
Brake fluid prices
Usually, the prices for DOT 4 brake fluid fluctuate around 600-700 rubles per 1 liter. Some manufacturers ask for 1,500 rubles for a similar brand.
DOT 5.1 costs from 1 100 rubles, depending on the manufacturer.
Security measures
To prevent the brake fluid from oxidizing, evaporating and absorbing moisture, it must be stored in an airtight container.
They are generally flammable and should be kept away from open flames and high temperatures.
In no case should you drink, even a small amount will lead to poisoning. If liquid comes into contact with eyes, rinse thoroughly with clean water and consult a doctor.
Before filling the brake system with fluid, it is necessary to thoroughly clean the master cylinder and bypass valves on the wheel cylinders of the brakes and the hydraulic vacuum booster from dirt, check and adjust the clearances between the pusher and the piston of the master cylinder, as well as between the pads and brake drums.
The brake system only needs to be filled with special brake fluid. Mixing of different brands of brake fluids is not allowed. It is strictly forbidden to add to the system even in the smallest amounts mineral oils, gasoline, kerosene or mixtures that cause destruction of rubber parts of the brake system.
How to pour alcohol into the brake system
In the absence of a special brake fluid, a mixture consisting of 50% (by weight) castor oil and 50% butyl alcohol can be poured into the system. Butyl alcohol can be replaced with isobutyl or ethyl alcohol, but keep in mind that ethyl alcohol evaporates more easily and the mixture can change quickly, especially in hot weather or with prolonged use of the brakes.
You cannot replace castor oil with glycerin, as its viscosity increases greatly with decreasing temperature.
If a different type of brake fluid is poured into the system, then it is necessary to remove the old fluid from it and thoroughly flush the entire brake system with alcohol, acetone or new fluid. When pouring brake fluid into the system, the maximum cleanliness must be observed, since if dirt enters the system, the brakes fail.
To fill the system and remove air from it, do the following:
- Unscrew the filler plug of the master cylinder and fill the cylinder with brake fluid.
- Remove the rubber protective cap of the bypass valve of the wheel cylinder of the right rear brake and replace it with a rubber hose, the other end of which is placed in the brake fluid, poured halfway into a glass vessel with a capacity of at least 0.5 liters.
- Unscrew the bypass valve by 1/2… 1/4 turn, then press the brake pedal several times. Press the pedal quickly and release slowly. In this case, the liquid from the master cylinder fills the system and displaces air from it, which comes out through the bypass valve, the hose and through the liquid into the vessel in the form of bubbles. During pumping, it is necessary to add fluid to the master cylinder, preventing the bottom from being exposed in its reservoir.
- After the exit of air from the system stops (the bubbles from the hose lowered into the glass vessel stop), it is necessary to tightly screw the bypass valve with the pedal depressed, remove the hose from the bypass valve and put on a protective cap.
- Bleed the brake system in the same way in the following sequence: front right brake, front left brake, rear left brake, hydraulic booster cylinder (through two bypass valves).
- After bleeding the brake system, add fluid to the master cylinder so that its level is 15-20 mm below the upper edge of the filler hole, and tighten the master cylinder plug tightly.
Before installing the plug, blow air through the vent hole.
If all brakes and actuator are correctly adjusted and there is no air in the system, then the brake pedal should not be depressed more than half the stroke when pressed, after which the pedal should feel "hard". Lowering the pedal more than half the stroke indicates large gaps between the brake pads and drums.
If the resistance of the pedal is insignificant, it can be squeezed almost all the way to the floor of the cab (“soft” pedal), this indicates that there is air in the system. In this case, it is necessary to continue pumping until the air is completely removed.
Do not press the brake pedal if at least one drum is removed, since the pistons will be squeezed out of the wheel cylinder under the fluid pressure and the fluid will flow out.
The fluid used to bleed the brakes can be reapplied, allowing it to settle until air bubbles are removed.
Bleeding the system must be carried out not only when the brake system is filled with fluid, but also when disconnecting any part of the hydraulic system for repair or replacement, i.e. when air can somehow enter the system.
Brake fluid is part of the hydraulic brake system. This is a working fluid that transfers pressure from the main brake cylinder to the wheel cylinders.
That is, a liquid conducts pressure in much the same way as wires conduct an electric current. And since the wires are not made from the first material that comes across, but from the one that is suitable, the liquid must have certain properties in order to be a good conductor of pressure in the car's braking system.
The main properties of brake fluid when working in brake systems:
- the brake fluid must remain liquid, that is, under operating conditions, it must not boil or freeze;
the working temperature of the brake fluid ranges from -50 (in severe frost) to + 150 with dynamic acceleration. If the brake fluid boils, steam bubbles displace some of it into the expansion tank of the GTZ and into the pipeline system. A liquid remains in the system, mixed with vapor bubbles. But if the liquid itself is incompressible, then microscopic gas bubbles are easily compressed. In the presence of gas in the brake system, the transmitted pressure will first of all go to compress the bubbles in their entire total volume, and only after that the pressure will be transferred to the liquid. With this outcome, the brake pedal will become soft, no sharp increase in effort will be felt, and braking will be ineffective.
- brake fluid must retain properties for a long time;
according to the regulations for the operation of cars, the brake fluid must be replaced every 12 months or more, all this time the brake fluid must be ready to work in emergency situations.
moisture also affects the boiling point of the brake fluid, and the boiling point decreases with increasing water concentration. All this is due to the constant volume of dissolved gas in the water and the boiling of water at 100 degrees Celsius, a temperature much lower than the upper limit of the operating temperature of the brake fluid. Therefore, the brake fluid must have a minimum hygroscopicity (moisture absorption). Moisture in the system contributes to corrosion of brake cylinders and pistons, and in cold weather, hydration plugs, obstruction of pipelines and, as a result, failure of the braking system are possible. In addition, at low temperatures, even if the brake fluid is not frozen, viscosity becomes a critical parameter - if it increases, then the brake response time will noticeably increase. So, in particular, the standard developed by the International Association of Transport Engineers (SAE) explicitly states that the viscosity of brake fluid at -40oС should not exceed 1800 cSt (mm2 / s). In addition to the SAE, the requirements for brake fluids are reflected in the regulations of the US Department of Transportation. Federal Motor Vehicle Safety Society - U.S. Department of transprotation. Federal motor carrier safety administration. They have three regulatory classes: DOT-3, DOT-4 and DOT-5.1. but more on that later.
The graph shows the dependence of the boiling point of the brake fluid ROS on the volumetric water content.
- do not react with rubber goods - rubber technical products that act as seals in the brake system;
When the rubber swells, changes in the shape and properties of rubber may lead to gaps, gaps in seals (rubber rings) and pipelines (rubber hoses), leading to failure of the brakes.
Lubricate mechanically rubbing vapors to increase service life and prevent scoring and excessive wear.
The lubricating properties of the fluid ensure the longest and most reliable operation of mechanical brake systems.
Considering such difficult requirements, modern brake fluid is quite complex in composition.
Basic compounds used in brake fluids
Glycol is the basis for brake fluid
Most modern products (including Neva, Tom and Rosa) are based on glycol mixtures. Glycols (aka diols) are alcohols with two hydroxyl OH groups. The simplest member of the glycol family is the well-known ethylene glycol, which is used in the production of antifreeze and antifreeze.
Butyl alcohol + oil - brake fluid base
Several decades ago, BSK appeared - a red brake fluid. It is made from butyl alcohol and castor oil, mixing them in a 1: 1 ratio (hence the name of the brake fluid - BSK). Today this is history, since the properties that BSK provides are far from modern requirements for brake fluids. The main disadvantage is the low boiling point - only 115оС. In addition, the increased viscosity of BSK at subzero temperatures. The only significant plus of this brake fluid is that BSK does not absorb water.
Glycol ether + polyester - brake fluid base
Brake fluid Neva is based on glycol ether mixed with polyester. An important ingredient in this fluid is an anti-corrosion additive. This liquid is highly hygroscopic and rapidly lowers the boiling point during use. Today this liquid is considered obsolete and is not produced.
Figure 1 brake fluids DOT-3, DOT-4, DOT-5.1
Tom - this liquid also contains glycol ether and a package of targeted additives.
Tomi has improved basic performance indicators in comparison with Neva. Therefore, it is ranked as a class that meets the requirements of DOT-3.
The best brake fluid of domestic production
The most perfect mass product of the domestic glycol family is Rosa. This fluid is based on boron-containing polyester with a special additive package. Therefore, it meets the DOT-4 class regulations.
DOT-4 dew is fully suitable for use in the braking system of a modern car.
Highest brake fluid standard DOT 5.1
DOT 5.1 brake fluid is hygroscopic, does not provoke corrosion and lasts longer than DOT-3, DOT-4 brake fluids having a glycol base. The only drawback of this brake fluid is its low prevalence and high price.
Brake fluid parameters depending on standards.
| Brake fluid | Manufacturer | Normative document according to which brake fluid is manufactured | DOT-3 class. Dry / humid boiling point as per standard (+205 / + 140) | Class by dOT-4 Standard Dry / Wet Boiling Temperature Standard (+230 /+ 155) |
DOT-5.1 class. Dry / humid boiling point as standard (+260 / + 180) | dry boiling temperature | wet boiling temperature |
| BSK | no information | no information | does not match | does not match | does not match | 115 | no info |
| "Neva" | no information | no information | does not match | does not match | does not match | 195 | 138 |
| "Tom" | JSC "KHIMPROM" Kemerovo | TU 2451-076-05757618-2000 | corresponds | does not match | does not match | 220 | 150 |
| "Dew" | NPP "MACROMER", Vladimir | TU 2451-354-10488057-99 | corresponds | does not match | 260 | 165 | |
| ROSDOT |
LLC "TOSOL-SINTEZ" |
TU 2451-004-36732629-99 | performance properties are higher | corresponds | does not match | 260 | 165 |
| HYDRAULAN 408 | BASF Germany | TTM 1.97.0738-2000 | performance properties are higher | corresponds | does not match | no info | no info |
| DOT-4 | LLC Lukoil-Permnefte- prsintez "Perm |
TU 2332-108-00148636-2000 | performance properties are higher | corresponds | does not match | 230 | 160 |
| TORSA DOT-4 | CJSC "BULGAR-SINTEZ" and CJSC "Bulgar Lada Plus" Kazan | TU 2332-001-49254410-2000 | performance properties are higher | corresponds | does not match | 230 | 160 |
BRAKE FLUIDS used in VAZ cars
Since 1970, the clutch and brake systems of VAZ cars have been filled with "NEVA" brake fluid with a boiling point of 195 ° C. In 1983, the "TOM" brake fluid with a boiling point of 215 ° C was introduced, and in 1988 the "ROSA" brake fluid with a boiling point of 260 ° C was introduced. Since all these liquids are hygroscopic, during operation, their boiling point decreases, reaching the limits that are dangerous from the point of view of the formation of steam locks in the brake system. Such limiting values \u200b\u200bof the boiling point for TZ "NEVA" can be achieved after one year of operation, for TZ "TOM" in two years, and for TZ "ROSA" in three years.
For this reason, AVTOVAZ excluded the use of TZH "NEVA" from the technical documentation, limited the use of TZH "TOM" to cars of the VAZ-2101 ... VAZ-2107 and VAZ-2121, VAZ-21213 models.
The technical requirements for brake fluids of the DOT-3 and DOT-4 types are set forth in TTM 1.97.0738-2000. TTM applies to brake fluids intended for hydraulic brake and clutch systems of VAZ vehicles of various models.
DOT 3, DOT 4 and DOT 5 can be mixed without silicone base. All brake fluids listed below are compatible and can be mixed with each other.
1. ROSDOT LLC "TOSOL-SINTEZ" Dzerzhinsk TU 2451-004-36732629-99
2. ROSA DOT-4 NPP "MACROMER", Vladimir TU 2451-354-10488057-99
3. TORSA DOT-4 CJSC "BULGAR-SINTEZ" and CJSC "Bulgar Lada Plus" Kazan TU 2332-001-49254410-2000
4. ROSA-DOT-3 NPP "MACROMER", Vladimir TU 2451-333-10488057-97
5. VOLUME JSC "KHIMPROM" Kemerovo TU 2451-076-05757618-2000
6. DOT-4 LLC "Lukoil-Permnefteorgsintez", Perm TU 2332-108-00148636-2000
7. HYDRAULAN 408 DOT-4 BASF Firm Germany ТТМ 1.97.0738-2000
8. MOTUL Hydraulic DOT 5 (based on silicone free polyglycols).
Do not mix the above brake fluids with LHM and DOT 5 silicone base.
That is, in other words, you can mix mineral with mineral, silicone with silicone and non-silicone based on polyglycols with similar brake fluids, so look on the bottle and carefully read the name of the brake fluid base and then just add it to the brake system.
Brake fluid used for braking systems with ABS
For brake systems with ABS, there are no specialized brake fluids and standard fluids with improved performance properties are used for them, that is, DOT-4 or DOT-5.1.
Requirements for compliance with safety measures when working with brake fluids
Store the product in a tightly closed container without moisture.
Aggressive towards varnishes, paints and leather.
In case of contact with skin, wash off with water.
Terms of operation and replacement of brake fluid
Replacement is done once every 12 or 24 months in accordance with the recommendations of the designers. AvtoVAZ regulates the terms - in two years or after 100 thousand kilometers.
Standards for brake fluid for vehicles.
Unfortunately, Russia has lost its weight in the world and the relevance of using internal standards in many industrial, technological procedures and regulations. At the moment, GOSTs are only advisory in nature, and anyone can issue TU, register with the standardization center and work on it. In this regard, in the Russian market of brake fluids, the American DOT standard (from the English Department of transport) is actively used, nothing more than the standard of the US Department of Transport, this organization was mentioned earlier. It is the Standard No. 116 for brake fluid intended for self-propelled vehicles that is currently the most popular and demanded when choosing a brake fluid.
