The brake system of both cars and trucks consists of many components. One of the important components is the brake force regulator. Not all motorists know how this element works and works. But if it is faulty, there may be an unpleasant surprise for the driver during emergency braking. Car owners call this component of the brake system a “sorcerer”. This node received such a name because its work was very mysterious and unpredictable. Let's try to understand the device, the principle of operation and the adjustment of this regulator.
The main task of regulators and braking physics
The grip force of a car wheel with the road surface, like the friction force, is proportional to vertical loads. The coefficient of proportionality is the coefficient of the level of grip of the tire with the road.
This value does not depend on a person. It can be determined based on the condition of the road and car tires. The higher the grip of the wheel with the asph alt surface during braking,the shorter the braking distance will be. And since inertia also acts on the car during the operation of the pads, the vertical load on the wheels is redistributed. Therefore, the force of impact on the disk must be uneven. The brake force regulator is also used to improve efficiency when braking when the machine is not loaded. In this case, the grip force will be completely different than in the case of a loaded car.
Where is the brake force regulator on the VAZ
On many domestic cars, the “sorcerer” is located in the rear of the body. It should be noted that the brake force regulator (including the VAZ 2170) is not installed on those models that are equipped with an ABS system. If we consider modern models produced by AvtoVAZ, namely Priora, Grant and Kalina, then the regulator is located on them on the left side of the bottom. When it comes to older AvtoVAZ models, the brake force regulator can be found on them in the right rear of the bottom. These are VAZ 2101-2107 cars.
How the brake force regulator works during braking
When the driver presses the pedal sharply, the rear of the body will rise, the front - on the contrary, will fall. And at this moment, the brake force regulator begins its work. After the device works, it will immediately allow the rear wheels to begin to slow down immediately after pressing the pedal. The fact is that if the wheels on the rear axle of the car start braking at the same time as the front axle, then there is a high probability of skidding.
If the wheels on the rear axle start to slow down later than the front ones, then the risk of skidding is reduced to almost zero. When the car slows down, the rear distance between the bottom and the rear beam increases. While this gap grows, the lever releases the regulator piston and due to this, the fluid line is blocked, which is suitable for the rear wheels. As a result, they will not be blocked, but will continue to rotate.
Brake force regulator device
It is fixed on the body bracket and connected on passenger cars with the rear axle beam on the rod and the torsion arm. The second end of the last element acts on the regulator piston. The input of the regulator is connected to the main brake cylinder, and the output is connected to the rear. The device is controlled by a drive connected to the rear beam. As for the design, the brake force regulator consists of a body divided into several cavities (usually two). One of them is connected to the main cylinder, the other - to the rear system. There are also pistons and valves, through which the access of brake fluid is blocked.
At the start of work, its pressure in the two chambers is the same. However, in the first, the fluid acts on a smaller area of the piston, while in the second, on a larger area. The piston tends to move, but cannot do so because of the centering spring. If pressure begins to increase in the master cylinder, then the piston can easily overcome the spring force, causing the valve tocut off fluid access. This is the classic principle of operation of the brake force regulator. Today there are hydraulic elements, pneumatic, electronically controlled.
Trucks and brake force regulator
The KamAZ vehicle is equipped with an automatic regulator. It performs almost the same tasks as the device in passenger cars. It automatically controls and distributes the force of the pads on the wheels of the rear axle, depending on how the axle load on the wheels changes. It also helps speed up their unlocking. The action of such a regulator is based on the change in air pressure in the chambers of the system on the rear of the trailer, depending on the axle loads with a decrease in speed. The KamAZ brake force regulator is mounted on the frame.
The lever and the rod through the elastic part, as well as the rod, are connected to the axle beams and the rear wheel bogie in such a way that distortions and twisting during the operation of the system will not affect the braking force. The elastic element is necessary to protect the adjusting device from various damages during vertical displacements of the rear axles. It also greatly reduces vibration and absorbs shocks when driving on rough roads.
Regulator device on KamAZ vehicles
This assembly consists of a valve, a valve lifter together with a drive. The device also has a piston with an inclined rib. There is also a membrane that is in connection with the piston. Inside the case there are connecting tubes. By the last air entersunder the piston, which ensures smooth operation of the system at the time of valve overlap. The regulator channels are attached to the top of the crane, and the second channel is connected to the brake chambers on the rear wheels. The third conclusion works with the atmosphere. When the car slows down, the air supplied from the top of the brake valve to the first channel of the regulator shifts the piston down, and the piston on the other side is compressed to the stop. The valve is pressed against the pusher seat and the second channel at this moment is more connected to the atmosphere. Further movement of the piston will then open the valve. Air from the first channel will enter the second, and then to the brake chambers. The brake force regulator MAZ has a practically similar device and principle of operation.
Devices from Wabco
Wabco is a manufacturer of truck parts. Among the huge range of products there are parts for brake systems. In the company's catalog you can find everything you need for the repair of trucks.
One of the devices this brand makes is the Wabco brake force regulator. It is suitable for installation not only on trucks, but also on trailers of various models and brands. Many truck owners have appreciated the quality of equipment and spare parts from this manufacturer. The quality of the regulator is much better than the standard device. It is installed on factory mounts.
How to check the "sorcerer"
On the example of a VAZ 2110 car, you cansee how the brake force regulator is tested. There are few symptoms. This is the withdrawal of the car to the side, frequent breakdowns into a skid, insufficiently effective braking. On the VAZ 2100, the RTS is located on the left under the bottom in the area of \u200b\u200bthe rear wheels. It is best to carry out all operations with it by raising the car on a lift, placing it on a flyover or viewing hole. The main defects of the device can be easily detected visually. If fluid leaks are observed, the cuff is most likely worn or damaged. If the regulator piston is in one position and does not want to move, then most likely it has soured. This defect can be identified through visual diagnostics.
If these problems occur, repairs will not help here. Only replacement can solve the situation. Many people replace a simple regulator with a brake force regulator valve. This system is considered more convenient. If the element is completely clean, there is a small gap between the drive lever and the plate, the stem moves perfectly in both directions when the pedal is pressed, then the mechanism is fully functional and nothing needs to be done with it.
How to regulate RTS
If we take cars of the VAZ brand, then the adjustment of the brake force regulator strongly depends on the position of the body. The adjustment must be performed not only during each maintenance, but also when replacing suspension parts - springs or shock absorbers, after repair work on the rear beam and when replacing it. To set up the car must be put on a flyover. This is done not only for convenience, but also forsetting the suspension to the equilibrium position. In this state, when pressing the trunk with your hands, the car will rock two or three times. So, to set up, you first need to loosen the fasteners to the bracket. It is necessary to achieve a gap of 2 mm between the elastic plate against which the stem rests and the lever. This is done by moving the mechanism.
Be aware that the process will have to overcome the resistance of the spring. They are quite large, so it is recommended to use a special tool or other suitable device. Then the bolts are tightened and the gaps are checked with a feeler gauge. If there is no such tool, then a 2 mm drill or a suitable coin can be used.
Running trials
Whether the adjustment is well done can only be understood on the go. You should accelerate to 40 km / h, and then press the pedal, and in the process of braking, evaluate how the car behaves. You should not be "thrown" forward. With a good adjustment, both parts of the car roll minimally.
