2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42
Each car should not only accelerate well, but also slow down. This function is performed by pads, drums and many other elements. The serviceability of each of them is a guarantee of the safety of the driver and passengers. Each brake system has a master brake cylinder. Its malfunctions, design and principle of operation are further in our article.
Characteristic
This cylinder is the central element of the brake system. Its purpose is to convert the mechanical forces from the brake pedal into pressure. This element works thanks to a liquid under high pressure.
Device
All modern cars are equipped with a two-piece master cylinder. If it is a front-wheel drive vehicle, the first circuit combines the braking forces of the front right and rear left wheels. The second - right rear and front left. As for rear-wheel drive vehicles, here are the contourswork differently. The first is responsible for the front wheels, and the second, respectively, for the rear.
Where is the brake master cylinder located? This element is attached to the vacuum cover. On top of the element is a plastic two-section reservoir with brake fluid (by the way, it is also poured into the clutch system, if it is controlled by a hydraulic drive). The container is provided with bypass and compensation holes. The tank itself serves to compensate for the liquid level in case of loss. It could be evaporation or a leak. It has level marks. Always keep an eye on him and keep him at the maximum. Some cars have a fluid level sensor that goes to the VAZ-2106 master brake cylinder. Faults associated with its leakage will be displayed on the instrument panel in the form of an emergency lamp. Before finding out the signs of a malfunction of the master brake cylinder, consider its structure and operation algorithm. This element consists of two consecutive pistons. The first of them rests on the amplifier rod, and the second is in a free position. Since they work under high pressure, the body is made of metal, and rubber gaskets are used as seals. Also in the design there are return springs that return and hold both pistons in their original position.
How does it work?
When the driver presses the brake pedal, the vacuum rod pushes the piston. When moving, it blocks the hole in the cylinder (compensatory). Pressure infirst, and then in the second circuit, increases significantly. The liquid begins to flow into the voids that were formed due to the movement of the first and second pistons. The movement of the latter occurs until the maximum pressure necessary for the operation of the discs and pads is generated in the circuit of the brake system.
When the pedal is released, the piston returns to its original position under the action of the return spring. Passing through a special hole, the level in the circuit drops to atmospheric pressure. It happens very quickly. But even with a sharp release of the pedal, a vacuum is not formed in the working circuit, due to the presence of hydraulic fluid. It fills the space behind the piston with its entire volume. With each new braking, the fluid flows smoothly and returns through the overflow hole to the plastic reservoir.
Emergency mode
It is worth noting the high reliability of the system. And even if there are malfunctions of the main brake cylinder (VAZ is no exception), the car will brake properly. This provides a second emergency circuit. If there is a leak in the first, the piston will move in the cylinder until it comes into contact with the second. And then it will begin to move, ensuring the correct operation of the brake mechanisms. But if there are leaks in the secondary circuit, the operation of the mechanism will be slightly different. The first piston will push the second one until it hits the top of the metal housing. Further, the pressure level in the primary circuit increases and the car startsto brake. And despite the fact that the system is running in emergency mode, the car will have time to slow down if necessary.
When there is a leak in the secondary circuit, the operation of the brake master cylinder is different. The first piston pushes out the second, after which it moves to the top of the metal housing. The pressure level in the primary circuit is rising. The car starts to slow down. Of course, having such malfunctions of the master brake cylinder, it is simply dangerous to operate a car without repair. But it is possible to get to the nearest garage or service station.
Causes and remedies
What are the signs of failure of the UAZ brake master cylinder? Malfunctions may consist in a drop in the liquid level. Yes, she constantly comes and goes from there. But this is only allowed when the system is running, that is, when the driver has pressed and released the pedal.
If, while standing in a parking lot or garage, you open the hood and see the minimum level, it is worth considering why this happened. This is mainly due to worn pads - the piston needs more fluid to provide compression work. Also, the causes of a malfunction of the master brake cylinder are in the breakdown of the tubes. They can be made from copper or aluminum. In places of bending they are rubber. If these are metal elements, then they cannot be bent - remember this when installing. It happens that the wheel frays the tube. On some vehicles, if the highway passesthrough the arch, it is enveloped by a protective spring. It does not allow the wheel to wipe the material to the ground. At a low fluid level, we carefully check the tightness of the entire system, including the working and master brake cylinder. If there is a leak, the tube must be replaced.
Low sensitivity threshold
There are other signs of a bad brake master cylinder. For example, the pedal began to work too low, almost to the floor. This happens if the so-called “sorcerer” is jammed - the brake force distribution regulator. The ball may have worn out or the hole may be clogged.
Remedy - cleaning the inside of the cylinder.
Soft Pedal
Another symptom that indicates a malfunction of the master brake cylinder is too soft a pedal. This means that air has accumulated in the system. It is impossible to operate a car with such a malfunction. There is a risk of overheating the system, since the air, when compressed, releases a huge amount of heat. Brake fluid will just boil. Eliminating airiness is very simple - you need to "bleed the brakes". To do this, unscrew the air release valve in the cylinder and press the pedal until the ideal liquid flows out of it. It does not mean the color, but the absence of bubbles in it. At the end of the work, the valve closes. The leaked liquid must be refilled into the system.
But if the problemoccurs constantly, it may be a faulty vacuum booster valve or system depressurization.
Pedal sinks to the floor
This is a significant breakdown. In this case, the malfunction of the master brake cylinder is inactive pistons that cannot generate the desired pressure. As a result, the pads (especially if it is a drum) are not able to compress normally. The car slows down badly. Also a commonplace reason is the wear of the pads. But this can be determined by the script. And it is best to keep a record of the replacement of consumables. This saves a lot of time.
Cylinder depressurization
If the car brakes badly and the fluid level in the tank is constantly falling, it is possible that the leak is in the cylinder itself. Carefully inspect the outlets of both circuits and their joints. There must be no leakage at the joints. It is very easy to identify it by oily spots around the cylinder and by a specific smell. And if in other cases you can "get off" by pumping the system and cleaning the channels, then only a replacement is needed here.
Especially if the damage concerns the metal case itself. Also, the old element is changed to a new one if there are scuffs on the piston. The cost of a new element is about 1-1.5 thousand rubles. If the leak occurs through the gasket, a master cylinder repair kit is purchased. All technological elements are changing - springs, elastic bands, cuffs.
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