How often do I change the brake fluid in the car?

About the brake fluid, probably, every driver knows. Almost everyone faced with its replacement or at least the need to top up it. And, of course, everyone cares about the question of how often it is necessary to change the brake fluid? Today we will try to answer this question.

What it is?

In the car, the cylinders are not only in the engine, but in the braking system. So, the main task of the liquid is the transfer of the piston motion of the master cylinder to the workers. возле колес и действуют непосредственно на колодки. The latter are located near the wheels and act directly on the pads. This liquid differs in composition from water in the first place in that it does not boil at high temperatures that arise during operation.

After all, the pressure in this system reaches several atmospheres. To avoid boiling, special additives are added to the brake fluid. They stabilize its properties.

Why should it be changed?

Unfortunately, the brake fluid is not permanent. Its main drawback is extreme hygroscopicity.

It is able to absorb water from the environment. Only 3% is enough to make it completely unusable. It is this property that makes the replacement of a liquid necessary. With the accumulation of water in it, it tends to earlier boil, and, therefore, to reduce the efficiency of work. When the system is depressurized, it inevitably contacts the air and absorbs moisture, which in the form of steam is always present in it. That the liquid is old, it's easy to check on the increased pedal stroke. Normally, it should be short enough, with increasing resistance at the end. The presence of water or, even worse, air in the system can be determined by the lack of effect during braking. The pedal has to literally "pump up" the brakes. This is very bad, and most importantly - it's dangerous.

Periodicity of replacement

Brake fluid has its lifespan. How often do I have to change the brake fluid?

The period is one and a half to two years or a run of 30-40 thousand kilometers. All details are given in the operating instructions. Of course, much depends on the type and type of brake fluid used. Below we will look at some of them.

Varieties

All modern brake fluids have DOT standards, which indicate the boiling temperature, as well as the viscosity at a certain temperature. Old cars used only organic products such as BSC.

They were made on the basis of butyl alcohol and castor oil. The main drawback - the products thicken at a negative temperature. How often do I change the brake fluid in such machines? It must be drained once a year. In addition, these cars are contra-indicated with modern brake fluids due to the destructive effect on rubber and metal connections in the system.

Features of compatibility of a brake liquid

With the compatibility of various types of funds should be guided by the characteristics of their composition. As already mentioned, there are several types of fluid. All of them differ from each other in their characteristics. So, let's consider them:

• DOT-3 is a liquid made of polyester and polyethylene glycol. The operating temperature in the system should not exceed 150 degrees. This is a bit, and such cars are old generation, equipped with inefficient brakes. DOT-3 can be mixed with a similar liquid DOT-4.
• DOT-4 is distinguished by the presence in its composition of additional additives. They raise the boiling point to 200 degrees. This is the most common brake fluid for modern high-speed cars. DOT-4 is compatible with DOT-3.
• DOT-5 has a silicone in its composition. The boiling point of such liquids reaches 260 degrees. This type is used in sports cars and is not compatible with all other types of brake equipment.
• DOT 5.1 / ABS - composition based on polyethylene glycol. It is used in brake systems with ABS. This fluid is also not compatible with other types.

As can be seen from the classification, only DOT-4 and DOT-3 can be mixed. Products based on silicone with all the advantages have a small resource and weak lubricating properties. The service life is only one year.

Some misconceptions and myths

There are many myths about the fluid in the automotive braking system. The first myth that this system, relatively speaking, is not hermetically sealed. It has compensation holes for the movement of air, which causes air to get inside.

This is the reason for the questions "why and how often it is necessary to change the brake fluid." There is an opinion that you do not need to change it, but you can simply top up it. But it is not advisable to do this. Over time, the brake fluid will be completely renewed, but as a whole it will not be considered fresh again. All liquid is considered to be replaced. Another myth is associated with the mixing, which has already been mentioned. It is highly recommended not to dilute various brake fluids, even one standard. Instruction manual is not just written. It must be strictly adhered to.

Brake system installation

The modern hydraulic system on all cars is structurally identical and differs in separate details. It is a two-circuit, with a diagonal or parallel separation. This means that the individual contours serve the front left and rear right wheel. And the second contour is the front right and back left. Parallel separation is performed by dividing the contours along the axes. This is done in order that in case of depressurization of one circuit, the second retained its tightness. This will allow you to stop the car in time.

Replacement procedure

After determining how often to change the brake fluid, you can go to the specifics of its replacement.

Before starting this work, you must open the brake fluid reservoir. Then slightly unscrew the connections for pumping on the brake cylinders of the wheels of the corresponding contour and put rubber hoses on them. Their ends must be lowered into jars of water. Then pump the pedal fluid in the system so that it all exits through these hoses. The latter should always be immersed. The liquid must be added to the reservoir, until a clean, new composition flows from the hose. After this, you can tighten the fittings and remove the hoses. So, in the tank and pipelines there will be a completely new facility. Mandatory procedure after the replacement of the brake fluid is its pumping. You can do it yourself.

Features of replacement on different cars

How often to change the brake fluid on different machines depends on the design of the vehicle itself.

The presence of an anti-lock system indicates the use of a specific liquid. We spoke about it earlier. As for how often to change the brake fluid of Land Cruiser, Prado and similar SUVs, one should keep in mind the operating recommendations and the fact that due to the considerable mass of the brakes they will work in more difficult conditions. The ingress of moisture inside is simply unacceptable.

Bleed by own hands

How often to change the brake fluid in the car, we already know. After each procedure, it is necessary to remove air from the system.

This is an obligatory work for any actions with brakes. It is also produced by replacing the brake hose, caliper or cylinder. The cap of the tank turns away, and the hose is put on the bleeder. Its end is lowered into the water. The assistant presses on the pedal and holds it in the floor. The coupling slightly turns away. Through it will leave the brake fluid with air bubbles.

The pedal at the same time falls to the floor, which the assistant continues to press. The coupling is wrapped, and the procedure is repeated until only the liquid starts out of the hose, without air. Thus, all four pipelines are pumped. After that, the level of liquid in the tank is replenished and the lid is wrapped.

Conclusion

Thus, it becomes clear how often to change the brake fluid in the car. This operation is important for the longevity of the braking system and, first of all, for the safety of road users. An old, burnt or just black liquid is a direct signal to replace it. In addition to water, it also contains dirt, which can help wedge working pistons.