The brake fluid is DOT-4. Brake fluid "Castrol" DOT-4: reviews of motorists

In brake systems of disk type of the majority of vehicles the brake liquid of DOT 4 is filled - one of the most popular and widespread among analogues. The main differences of such agents are the boiling point, the composition and the property of absorbing moisture vapor. Category DOT 4 is considered the most high-quality and universal. When compared with DOT 3, it absorbs fewer times water and keeps the boiling point unchanged for a long time. Such features of the composition make it possible to extend its useful life.

Types of brake fluids

The systematization of DOT braking compositions was formed by the American Department of Transport. FMVSS safety standards were used as the basis for creating these standards. In translation, the abbreviation DOT stands for "Transport Security Department". The substances that bind moisture are indicated by the figure 4. Such agents do not pass certification according to GOST.

Since DOT 4 is not considered a refinery product, it also has a corresponding octagonal figure of yellow color, bordered by a black line. In the center of the figure is the brake system. A similar symbol, diagonally crossed out, indicates that such a composition can not be poured into the system.

The boiling point and viscosity of a dry and moisture-filled liquid are the criteria by which brake compounds are divided into types. The basis of DOT 3 and DOT 4 is considered to be polyglycols, but DOT 5 is created on the basis of silicone, because of what these categories are not mixed together. To create liquids of DOT 3 and DOT 4 categories, the same substances are used, so they can be mixed and interchanged.

Marking and composition of brake fluids DOT 4

The brake fluid DOT 4 in its base contains linear polyethers and polyalkylene glycols. In most cases, polyethylene glycol is used in the production of such formulations, however, it is often indicated on a package under a different name, since a variety of additives and liquid polymers are taken into account.

Unlike the predecessor DOT 3, DOT 4 liquid contains special additives in its composition - for example, borates. They bind water that enters the material from the air during operation.

In sports cars, brake fluids DOT 5.1, obtained by adding special additives and additives to the liquid of the DOT 4 standard, are used.

Brake fluid compatibility DOT 4

For many car enthusiasts, compatibility of brake fluids of different classes and categories remains one of the most urgent and burning issues. Specialists, as a rule, advise to use compositions of known brands - such as the brake fluid "Castrol" or the brake fluid "Bosch" DOT 4. The marking of the composition must be observed.

The Russian market of automotive products presents a huge number of different brake fluids. Mixing them with each other is not advised, but in emergency cases it can be done, but it is desirable to be guided by certain rules.

The brake fluid DOT 4 can be mixed with such analogs as DOT 3, DOT 4.5, DOT 5.1. It is prohibited to dilute it with silicone-based agents, such as DOT 5 and DOT 5.1 (ABS).

Brake Fluid DOT 4 - Characteristics

The main physicochemical parameters of the compositions that affect their quality are:

• viscosity;
• boiling temperature;
• Ability to absorb moisture vapor;
• Resistance to corrosion.

According to the requirements for the DOT 4 standard, the boiling point should not be below 250 ° C. This can be reduced to 165 ° C for liquids that absorb moisture from the environment in a total amount of up to 3.5%.

The viscosity of the liquid is measured with a viscometer. This parameter must not exceed 750 mm ² / s. In practice, one of the main properties is only viscosity, while the density of the brake fluid is practically not taken into account anywhere.

The stability of the DOT 4 liquid to corrosion directly depends on its acidity level. Normal is the pH value of 7.0-11.5 units.

Brake fluid service life

Depending on the additives and additives, hygroscopicity and working conditions, the life of the agent may vary. For example, low-quality parts of the brake system can change the characteristics of the brake fluid, which affects its functions and work resource. For this reason, the brake fluid is changed every 2-2.5 years.

Why DOT 4?

The brake fluid DOT 4 has the following advantages, due to which it is one of the most popular in the whole world:

• reliability;
• Affordable prices;
• A wide range of temperatures at which it can be used.

Expensive DOT 5.1 is almost not used by car enthusiasts, because it costs more, but its functionality is no different from DOT 4. Tests conducted by specialists and amateurs show that the gold standard is the brake fluid DOT 4. The reviews left on the composition confirm Its reliability and high quality, coupled with an acceptable cost.

Boiling temperature

The kinetic energy of the car during the braking is transformed into heat. Pads, heated, transfer it to the pistons and the body of the caliper, which he already heats the brake fluid. Proceeding from this, the first requirement is put forward to it: a high boiling point, which will avoid the "failure" of the brake pedal. High high-speed mode of modern cars has led to the fact that old types of such compounds stopped coping with their functions, and they were replaced by brake fluid DOT 4. "Toyota", one of the most authoritative automotive concerns in the world, advises to use just such compounds.

Resistance to corrosion

The second requirement is minimal corrosive activity. Oxidation of the metal of the pistons is not the worst thing that can happen, corrosion of brake lines is much more dangerous. Provide a high boiling point of the brake fluid was made possible only through the use of polyethylene glycol base, which is characterized by a high level of hygroscopicity. Because of this, DOT 4 formulations are stored only in tightly closed packages. A liquid that has accumulated a large amount of water not only accelerates the corrosion processes in the braking system, but also boils at a much lower temperature. This is often found in motorcycles and sports cars: the "dips" of the brakes during an aggressive and fast ride can cause a serious accident.

Lubricating properties

Good lubricity is the third requirement for brake fluids. These characteristics help to reduce wear as the hydraulic unit ABS, and the cuffs of the cylinders of the brake system. The standard DOT 4 on these parameters is slightly inferior to the new DOT 5, while the latter has a higher boiling point and a lower level of hygroscopicity, which allows it to be used for fast driving. DOT 5.1 fluids were developed for vehicles equipped with an anti-lock system. It is intended to introduce a small amount of antifriction additives into the glycol base. For most vehicles, it is advisable to use liquids of this class, as they are compatible with seals that are designed for previous fluid standards.

High Viscosity

A high level of viscosity is the fourth requirement for brake fluids. Preservation of the viscosity of the fluid allows the brake system to operate normally at any ambient temperature. This parameter is most important for cars with ABS. Indeed, the solidification of the liquid can cause the failure of the hydraulic unit on those cars on which the course stabilization is tied to the anti-lock system. This also includes modern crossovers: failures of the traction distribution system will cause poor controllability of the car.

Mobil Brake Fluid

The composition is recommended by the manufacturer for use in drum, disc and anti-slip brake systems installed on vehicles of medium power.

The brake fluid "Mobile" DOT 4 is applied in accordance with the following recommendations:

• Fills only in concentrated form from a new package or tightly closed.
• Immediately after use, the bottle should be tightly closed, as the compound quickly absorbs moisture from the environment, which adversely affects its operational life.
• The drained brake fluid can not be re-used.
• Spilled composition is immediately removed, as the paint and varnish coating of the body can deteriorate.
• The period of replacement of brake fluid - every two years or every 40 thousand kilometers.
• Fully complies with DOT 4 standards and can be used for ABS systems.
• Can be mixed with brake fluids of categories DOT 4 and DOT 3.

Brake fluid "Castrol"

Despite the fact that the brake fluid "Castrol" DOT 4 is certified in accordance with the standard DOT 4, its boiling point exceeds the requirements and is 265 ^о С, with water - 175 ^о С. According to the manufacturer's recommendations, it needs to be changed every two years, accordingly, its Can be filled in sports cars.

Brake fluid "Castrol" DOT 4 is realized in a very inconvenient packing: a bottle of 1 liter can not be found in car shops. For this reason, when replacing the liquid, you will have to buy several half-liter containers, overpaying for packaging. This is noted by many car owners.

Advantages of this brake fluid:

• Resistance to boiling even when moisture gets into the composition.
• Compliance with more stringent standards.
• Ideal for cars with ABS - it has good viscosity properties.

Brake fluid "Rosa"

Brake fluid "Rosa" DOT 4 - a mixture that includes anti-corrosion and antioxidant additives and boron-containing polyester. It differs with good boiling points in dry and wet form - 260 ^о С and 165 ^о С, respectively. It can be operated at an ambient temperature ranging from -40 ° C to +45 ° C.

Brake fluid "Rosa" DOT 4 is used in brake systems of cars and trucks, including in front-wheel drive vehicles of domestic production.

The life of the liquid is three years. It can be mixed with such compounds as "Neva" and "Tom", without loss of characteristics.

Sintec Brake Fluid

Perhaps, one of the most affordable in the price plan (only 100 r) brake fluids of domestic production. The brake fluid "Super" DOT 4 is manufactured at the Obninskorgsintez plant. Despite domestic production, by its characteristics it can outrun many import analogues: the boiling point is 240 ° C in dry form and 155 ° C in the wet one. Ideal for a measured ride, a slight difference in viscosity during driving is not felt.

The only drawback is the unstable characteristics: all tests that passed the brake fluid from Obninsk showed different results. Of course, this does not affect the requirements of the standard, but does not say anything good about the manufacturer.

Brake fluid Liqui Moly

Liqui Moly brake fluid loses its characteristics in its characteristics: the boiling point for a dry and wet version is 230 ° C and 155 ° C, respectively, at a low temperature the viscosity is 1800 mm ² / s. The characteristics of the composition are ideally in accordance with DOT 4 standards, but do not exceed them. Affordable price 300 rub. To some extent it compensates, however, it is definitely not worth using such a liquid in our climate for cars with ABS.

Separately it is worth noting the excellent lubricating and anticorrosive properties of Liqui Moly, which the manufacturer has focused on. By its property, this brake fluid is ideal for drivers who prefer a quiet rhythm of driving and living in the middle zone of our country.

The advantages of brake fluid Liqui Moly:

1. Excellent anti-corrosion properties.
2. Protection of brake hoses and rubber seals.

Brake fluid selection

A suitable brake fluid is selected according to the parameters of the vehicle. You can find out which composition was filled in the factory, and what can be used in the future, in the manual for repair and operation of the car. You can also ask an authorized dealer.

It is worth paying attention to such parameters of the brake fluid as the boiling point in a dry and wet form, viscosity and standard. The categories below DOT 4 can not be used for cars equipped with an anti-lock system, as this can lead to breakdown of both the ABS itself and the braking system.

You can contact the service station from an authorized dealer to diagnose the system and fill a new brake fluid.