Adjusting the brake booster rod 2110

Thank you all for your response!

yaris

I have self-feeding cylinders.

It's all about the gap between the GTZ and the VUT rod! I have not seen anyone write about adjusting it in any article!

I quote: Before installing the master brake cylinder, we control the protrusion of the head of its adjusting bolt relative to the mounting plane of the master brake cylinder flange, which should be 1.25-0.2 mm

. To adjust the protrusion of the bolt head, turn it with an 8-point wrench.

This was the reason for the brakes being applied almost to the floor! But the “instructions” don’t say a word that the rod itself needs to be held with pliers and the “head” itself must be turned. And the key is not "on" 8

"But still "at
7
". I removed the GTZ three times to adjust the rod. And then this rod needs to be “inserted” back! I will say this is not very easy, since the pipeline is already connected and laid! It’s good that I didn’t leave the original brake fluid reservoir with its rubber hoses. I feel like I suffered even more then! The pedal began to take where it should be - in the middle! But “the music didn’t play for long!” Still, I guessed wrong.

Thanks again to Deeptown

for the hint where to dig, for the consultation at the moment when I stopped near the Dorogozhychi metro station with an oak pedal and almost blocked brakes. I had one adjustable wrench with me, thanks to it I unscrewed the GTZ and relieved the pressure. Then, on the floor with live brakes, I drove to the garage. There, within 5 minutes I removed everything, tightened the rod 5 turns and calmly drove home. But I see that I can add a couple more turns.

The vacuum brake booster (VBR) is one of the main components of the vehicle braking system. Even the slightest breakdown can trigger a failure of the entire system and lead to serious consequences.

When to repair and when to replace?

• The VUT will have to be changed if the diaphragm, return spring or one of the valves is damaged. Then the car owner will simply be forced to remove the VUT and replace it. Moreover, this will need to be done as quickly as possible. Replacement in this case is the most reasonable solution, since it is not always possible to find individual spare parts for VUT on sale (this is especially true for diaphragms).
• It is advisable to carry out repairs in case of damage to external hoses. The hose may crack, the clamp on it may become loose, which leads to a loss of tightness, etc. All these problems can be eliminated without replacing the VUT. A leak in the system is, of course, bad, but it is not a critical failure (unless the driver is annoyed by the hissing in the cabin).

Repair and repair

To repair a vacuum pump, you must first stop its operation, then lift it to the surface and inspect it. There can be many reasons for malfunctions; we need to look at them in more detail. What to do if the pump is working, but water is not pumping from the well, there is no rise? In this case, you need to do the following:

Diagram of a vibration pump.

1. The pump rises to the surface already turned off, after which you should check whether there are any leaks in the equipment pipelines and whether the check valve is working correctly. After this, all joints of the device are inspected, since the cause of the malfunction is usually the entry of foreign objects into the housing. This applies to sand, small particles of clay and debris, leaves and other things. It is quite possible that the spring and the check valve itself have failed due to clogging.
2. It is necessary to check the pipeline located between the well and the pump; there should always be water in it. The pump should not work if there is no water. If there is no liquid, then it is necessary to fill the pipeline through a special filling hole provided in the housing.
3. The cause of the malfunction may also be that the well or well is simply dry; this situation is not anything exceptional. In this case, it is recommended to lower the pipeline or suction pump hose deeper. It is possible that the water level has dropped, but it may also be completely absent. This needs to be checked immediately. It must be remembered that the distance from the water surface to the pump should not exceed the maximum specified by the manufacturer. The water level must be carefully monitored.
4. The cause of the breakdown may be the formation of a hole between the impeller and the housing; this phenomenon is caused by the increased abrasiveness of the water in the well.
   To avoid this breakdown, experts advise immediately taking this possibility into account at the equipment design stage and conducting water tests. It is enough to immediately install filters and special means to reduce abrasiveness. Often the cause of development is ordinary sand, which can be found at the bottom of any well or borehole. In this case, the equipment begins to work on its own; you should not expect performance from the pump. The repair is simple; it is enough to replace the housing and impeller, if they are commercially available. Diagram of the device of a vacuum liquid ring pump.
5. There is another reason why such a breakdown occurred and the vacuum pump does not work. The network supplying the equipment is experiencing low voltage or constant surges. You should call an electrician or use special equipment to maintain the required voltage in the network.

Design and principle of operation of VUT

The vacuum amplifier is a metal “barrel” consisting of the following parts (the numbering in the list coincides with the positions in the diagram):

1. The body is cylindrical in shape.
2. Pressure rod of the main brake cylinder.
3. A cover connected to the body by point rolling.
4. Piston.
5. Bypass valve.
6. Brake pedal pusher.
7. Air filter.
8. Buffer insert.
9. Internal plastic housing.
10. Rubber membrane.
11. Spring for return of the inner housing with membrane.
12. Connection fitting.
13. Check valve.
14. Vacuum pipe.

    
    The internal cavity of the amplifier is divided by a rubber diaphragm into 2 working chambers

The letter “A” in the diagram indicates the chamber for supplying vacuum, the letters “B” and “C” are the internal channels, and “D” is the cavity communicating with the atmosphere. Rod pos. 2 rests against the mating part of the main brake cylinder (abbreviated as GTZ), the pusher pos. 6 is attached to the pedal.

The unit is capable of operating in 3 modes:

1. The engine is running, but the driver does not press the brake. Vacuum from the manifold is supplied through channels “B” and “C” into both chambers; the valve is closed and does not allow atmospheric air inside. The spring holds the diaphragm in its original position.
2. Standard braking. The pedal is partially pressed, the valve releases air (through the filter) into chamber “G”, which is why the vacuum force in cavity “A” helps to press on the GTZ rod. The plastic body will move forward and rest against the piston, and the movement of the rod will stop.
3. Emergency braking. In this case, the effect of vacuum on the membrane and housing is not limited; the master cylinder rod is squeezed all the way.

Due to the pressure difference in the two chambers, the membrane helps to put pressure on the master cylinder rod

After releasing the pedal, the spring throws the body and membrane back to their original position, and the atmospheric valve closes. The check valve at the inlet of the pipe serves as protection against sudden air injection from the manifold.

Gas breakthrough into the intake manifold and further into the brake booster occurs on extremely worn engines. The reason is a loose fit of the intake valve to the cylinder head seat. During the compression stroke, the piston creates a pressure of about 7-8 atm and pushes some of the gases back into the manifold. If the check valve does not work, they will begin to penetrate into the vacuum chamber, reducing the efficiency of the VUT.

Video: how a vacuum brake booster works

Adjusting the rod of the vacuum brake booster UAZ

Often, after replacing the VUT, problems appear, and the car no longer brakes as well as it did before with a working “vacuum system” - the brake pedal takes off at the very end, or the system does not fully release the brakes. The whole point here is the rod that presses on the GTZ piston - it may not be adjusted from the factory. This rod has an adjusting screw, which is secured with a locknut. On UAZ cars (we don’t take the “Patriot” model into account), we check the rod adjustment as follows:

• push the rod all the way back;
• take a metal ruler or feeler gauge to adjust the valves and lay it along the body;
• We measure the protrusion above the body with a caliper - the rod should extend approximately 7.8-8.0 mm;
• if this distance does not correspond to the norm, loosen the lock nut and use the adjusting screw to increase or decrease the length of the rod;
• Having established the desired size, fix the screw with a lock nut.

Even on the UAZ Hunter, the pedal can “take” at the very end, and it has a large free play

It is necessary to pay attention to the position of the pedal - if it is too low from the floor in the cabin, it needs to be adjusted:

• unscrew the brake light mounting nuts on the brake pedal;
• disconnect the wires from the brake light sensor;
• Use two 19 mm nuts to raise the pedal, press the brake to check the free play, and if the pedal is adjusted normally, tighten the nuts.

https://youtube.com/watch?v=iTMZDTj0ats

Source

How to check the vacuum booster

If the symptoms listed above occur, the vacuum unit must be checked. You can determine the functionality of the device without removing it from the car. For diagnostics, we need a rubber bulb from a hydrometer and a screwdriver (slotted or Phillips, depending on the type of clamps).

We carry out verification work in the following order:

1. Turn on the parking brake.
2. We sit in the cabin and press the brake pedal 5-6 times without starting the engine. On the last press, leave the pedal in the middle of its travel.
3. We take our foot off the pedal and start the power plant. When the “vacuum” is working, the pedal will move down a short distance.
4. If this does not happen, turn off the engine and move on to the engine compartment. We find the amplifier housing there, inspect the check valve flange and the end of the connecting hose. If they have visible breaks or cracks, we prepare to replace the damaged parts.

Video: checking VUT

Personal experience of car owners.

“I am a driver with little experience, so it was very difficult for me to independently determine the cause of the pedal hardness. I couldn’t even figure out how to remove this or that part in order to diagnose specific problems. In the end, I took my Audi A6 to a service station. The craftsmen working there determined the nature of the damage without even removing the units. Correct diagnostics helped me significantly save on repairs.”

“When the amplifier of my VAZ 2114 broke down, I verified that it was faulty in a simple way. To do this, the hose is removed and the amplifier is turned off. The presence of a vacuum when starting the engine indicates that the “vacuum valve” is faulty.”

“The vacuum booster and cylinders are very difficult to diagnose. The best vehicle diagnostics can be provided only by those car services that have pressure gauges.”

How to make a replacement?

Replacement is carried out using a set of keys and screwdrivers. The vacuum brake booster is located under the hood, so work can be done in the garage or outside. The replacement takes place as follows:

First you need to disassemble the wall of the VAZ 2110 engine compartment, then remove the frill. This element is attached using a seal and upholstery;

Important! The most unpleasant moment in dismantling the vacuum brake booster is unscrewing the four nuts in the interior. To get to them you will have to remove several elements of the dashboard.

Reasons for checking the performance of the vacuum brake booster

The car's braking system will not completely fail, even if the booster breaks down, but the driver will have to make much more effort to slow down the car. A clear sign of VUT failure is that the pedal becomes “hard” and braking efficiency drops sharply. This leads to a dangerous situation on the road.

In addition, other signs appear:

• free play increases to half;
• the operation of the power unit becomes unstable, this is especially noticeable at idle;
• the brakes “stick”, that is, the car continues to slow down even when the brake pedal has already been released.

Important. The VUT check must be carried out only when the car engine is running, since the amplifier can operate correctly only when vacuum is supplied from the engine.

Consider the reasons why the above damage to the vacuum booster may occur:

Consider the reasons why the above damage to the vacuum booster may occur:

• the connection of the vacuum hose is loose, or air is leaking through damage in the hose;
• loss of tightness due to wear of the diaphragm;
• air valve failure;
• depressurization of the housing;
• decrease in spring elasticity.

You can seal the connection and replace the pipe yourself, just don’t forget to check the “vacuum seal” for functionality. However, if the check shows that the amplifier is broken, then the entire mechanism will probably have to be replaced.

Adjusting the free play of the brake pedal on a VAZ 2107

VAZ 2107 | Adjusting the foot brake pedal

Installation height of the foot brake pedal in the released state

The height of the foot brake pedal is the distance from the floor panel (the carpet is not removed) to the center point of the surface of the rubber pad (refer to the illustration above). If the measurement result is outside the acceptable range (see Specifications), appropriate adjustments must be made.

Specifications. If necessary, adjust the position of the sensor-switch on the support bracket accordingly. 9. Having completed the adjustment, firmly tighten the locknut of the sensor-switch and connect the electrical wiring to the assembly. 10. Make sure that the brake lights work properly even when you lightly depress the foot brake pedal. When you release the pedal, the brake lights should go out. 11. Now you need to measure the free play of the pedal. 12. With the engine off, depress the foot brake pedal several times to remove residual vacuum from the vacuum booster assembly.

If the measurement result is outside the permissible range (see Specifications), repeat the adjustment of the brake light switch.

Compare the measurement result with the requirements of the Specifications and, if necessary, check the condition of the brake system. 17. Check the system for signs of developing leaks.

Adjustment and repair of the unit after checking the vacuum brake booster

In general, adjusting the VUT comes down to adjusting the free play of the brake pedal. To set it correctly, you need to adjust the length of the rod. The adjustment bolt controls the gap/protrusion. Correctly adjusting the position of the bolt itself will allow you to set the ideal timing of the valves.

When the leak test is completed, do not forget to adjust the free play of the brake pedal. Adjusting the rod length creates a gap that determines the amount of pressure on the brake cylinder

Therefore, it is very important to set the rod length correctly and set the appropriate gap. The free play of the pedal when the engine is not running should be from five to fourteen millimeters

This gap is controlled by a bolt located above the plane of the vacuum brake booster. A small gap leads to jamming of the working cylinder, resulting in rapid wear of the pads and increased fuel consumption of the car. In addition, the car begins to slow down randomly, as if you were driving with a handbrake. A large gap, on the contrary, leads to an increase in pedal travel, which indicates a violation of the tightness in the assembly

The free play of the pedal when the engine is not running should be from five to fourteen millimeters. This gap is controlled by a bolt located above the plane of the vacuum brake booster. A small gap leads to jamming of the working cylinder, resulting in rapid wear of the pads and increased fuel consumption of the car. In addition, the car begins to slow down randomly, as if you were driving with a handbrake. A large gap, on the contrary, leads to an increase in pedal travel, which indicates a violation of the tightness in the assembly.

Above we described how to check the operation of the brake vacuum device and adjust its operation if necessary. Now let's say a few words about its repair.

To ensure your own safety if your amplifier breaks down, take immediate action to repair or replace it. And if you can replace vacuum hoses in gasoline cars or pumps in diesel cars yourself, without resorting to the services of a car service, then it is recommended to entrust more serious work to professionals.

Of course, it costs some money, but when your own safety is at stake, it is better not to skimp. Contact the specialists. They will not only carry out the inspection competently, but also perform all the necessary work efficiently and with a guarantee.

It should be noted that after repair, it is important to synchronize the wheels when braking and check the ABS/ESP system. This requires a diagnostic stand and specialized equipment.

There are times when it is more expensive to repair a vacuum cleaner than to purchase a used amplifier that is in good condition. Therefore, it is recommended to look for the device at a disassembly site if necessary.

If you feel confident in your own abilities and, after checking, decide to repair the faulty vacuum booster yourself, then proceed as follows.

To begin, remove all the upholstery in the engine compartment and remove the windshield trim. Do not remove the tubes leading to the GTZ. This may allow air to enter the system.

Next, unscrew the cylinder from the vacuum booster and carefully tilt it forward to prevent deformation of the brake pipes. Before doing this, the vacuum transfer hose must be removed from the amplifier fitting

Carefully study the recommendations given by the manufacturer and proceed to dismantling the amplifier. Unscrew the mounting bolts and disconnect the terminal of the wire going to the brake light.

Only then remove the pedal using a special tool. If you are well versed in the design of the car, you can cope with checking and repairing the VUT. However, it is better to first go online and find instructions with an amplifier circuit. This will significantly speed up the implementation of the task and increase your chances of success.

How to repair or replace parts

Hisses when braking (with video example)

In the following video you can hear this characteristic sound:

By the way, according to the instructions, the standard “vacuum unit” of the VAZ-2110 cannot be repaired, only replaced, but we “do it ourselves.” And judging by the number of different instructions for self-repairing cars posted on the Internet, it can be argued that any domestic car enthusiast with more than five years of experience can safely be awarded the title of design engineer in absentia. Therefore, we will consider the repair procedure, especially since the difference in cost between the repair kit and the vacuum booster itself is disproportionately high.

In any case, first we will have to dismantle the VUT; for this we will need a minimum of available tools.

Tools

• Open-end and socket wrenches in sizes “10”, “13”, “17”;
• Powerful flat screwdriver;
• Repair kit or VUT assembled;
• Sealant and a little desire to do it yourself.

Operating mode

The pump pumps water from the well, but does not turn off. Breakdowns can be different, the reasons are usually the following:

Diagram of the pressure switch device.

1. The relay needs to be adjusted. For this, two small springs are used. Using a large spring, you need to adjust the lower and upper limits for turning on/off, and using a small spring, you need to adjust the pressure difference when changing such limits. Sometimes it happens that during long-term operation, wear develops and the operating pressure changes. That is why the settings already need adjustment, they differ from the factory ones. It is necessary to reduce the tension of the springs by turning them in the “-” direction clockwise. But it is not recommended to overuse this method, since the settings can be completely lost and you will have to call a technician for repairs.
2. Salts with poor quality of supplied water can cause the inlet of the control relay to become clogged. In this case, the sensor stops monitoring the readings and the pump does not turn off even when the desired readings are achieved. It is necessary to stop the equipment manually, and then clean this hole.

Why do you hear a hissing sound when you press the brake pedal? Let's look at possible reasons"

Why do you hear a hissing sound when you press the brake pedal? Let's look at possible reasons

Brakes are one of the main components of any car. And if, when you press the brake pedal, you hear hissing, creaking, the structure itself fails or, on the contrary, is too hard, you need to urgently correct the situation, do not delay or shelve possible repairs. Or at least diagnose the causes of trouble. Knowledge and understanding of the problem leads to its fastest resolution, and timely correction can save you from unforeseen situations on the road.

Why do you hear a hissing sound when you press the brake pedal?

This kind of mistake can happen on many cars when trying to stop. Moreover, this happens regardless of the year of manufacture of the car, model, domestic or imported production. As they say, it happens to everyone. What are the reasons? Let's try to take a closer look in this article.

This suspicious thorn

Some drivers are almost maniacally suspicious of all kinds of noise and hissing, tapping and rattling. Even if they are the quietest and are completely allowed (by the manufacturers themselves or expert craftsmen) according to the staffing schedule. It's the same story with the brake pedal. When you press it, in many cases you will hear a very slight hiss heard in the cabin, almost from under the pedal itself.

Let’s immediately make a reservation that the experiment must be carried out with the engine running (idling), with the windows rolled down and the doors closed, additional electrical appliances and the media system with speakers turned off. And there is nothing military in this quiet sound! For example, one of the experienced car enthusiasts claims: throughout his entire driving experience (from a “penny” to a Honda Accord), this faint thorn was always heard.

This is understandable - the vacuum must be released. After all, the structure of its design planned by the manufacturers includes two chambers, between which different pressures arise when the brakes are pressed.

Roughly speaking, the more actively you press, the more effective it is. And when the corresponding pedal is released, the pressure is equalized, and the diaphragm returns to its original position. Therefore, due to the principle of operation of the device, there should always be a light spike! But we repeat, it should be small enough and practically imperceptible, and not in any way affect the normal operation of your car’s engine. Only then is it considered normal.

Brake vacuum is the most common cause

It's another matter if the texture of the sound differs significantly from the ear. That is, the hissing turns out to be quite loud and, as it were, choking. At the same time, when pressing on the brake pedal when it is cold, we feel its movement being excessively stiff. And also - the buoyancy of the engine speed (and sometimes it can stall).

In such cases, you should pay close attention to the vacuum booster as a possible cause of the problem. Well, a tight pedal, of course, could also be due to frost, for example, until the main one warms up. But the revs and a fairly strong hiss are already direct indicators that you need to look under the hood!

But the revs and a fairly strong hiss are already direct indicators that you need to look under the hood!

How to check it?

The car's braking system is subjected to constant loads, and with the so-called sporty style of city driving, it is also subject to overloads. This happens regularly even with a measured and leisurely rhythm - there is no escape from this problem. Therefore, this unit must be regularly tested to ensure maximum driving safety for the driver and passengers. So it is with the brake vacuum story.

As a rule, problems with its operation occur due to the failure of a special diaphragm located inside the device. It bursts, cracks, and ceases to perform its duties—to create a vacuum. Sometimes the exhaust valve also malfunctions. Checking the functionality of the vacuum on their own, available to every driver, is carried out in the following way.

We start the engine and let it idle for a while until it reaches ;

We turn off the engine;

Press the brake;

The first press will be no different from the normal one when the unit is running. The pedal must be pressed as much as possible: at the same time, the diaphragm in the amplifier is extended and a vacuum is created;

Release the pedal and press it again. If there is something wrong with the system, then during the second approach a vacuum will not be able to be created, and you will tactilely observe an uncharacteristic small stroke of the pedal itself. These changes indicate a breakdown in the brake booster.

Device

The operating principle of this mechanism is based on the influence of atmospheric pressure of the external environment directly on the discharged area. The device itself looks like a chamber, which is divided into two halves by a special elastic membrane.

Its first part is connected to the atmosphere, and the second is connected to the exhaust manifold of the engine, which creates a lower pressure. Due to different pressures, the membrane bends towards the rarefied air, and part of its energy is transferred to the elements of the car’s braking system.

Features of repair of UAZ vacuum amplifiers

Unlike the vacuum amplifiers of VAZ cars, the VUT housing on UAZ cars is very durable, and it is not at all easy to halve it. You can bend the protrusions using a pry bar and a hammer, but this way the work is done in violation of the technology - according to the instructions, you need to rotate one half relative to the other. The biggest problem during disassembly is the “halving” of the body - sometimes these parts boil so much that it is impossible to disassemble the assembly. Car owners are advised not to press one body into another under any circumstances - then turning will definitely not work.

Another problem in repairing “vacuum units” is the low quality of spare parts in the repair kit; sometimes the installed parts are not enough for six months. Motorists advise not to do repairs, but to buy a new spare part, although there is another disadvantage - VUT for cars like UAZ-469 or UAZ-452 is not cheap, about 3 thousand rubles. As an option, you can pick up a “vacuum” from a foreign car at a car disassembly shop, whose mountings fit the main brake cylinder, and install it on the car by fitting it. The result is cheaper and more reliable - imported parts, even in used condition, last for several years without any complaints.

Vacuum booster Lada Kalina

Miscellaneous

The vacuum booster drives the brake cylinder rod and builds up pressure in the brake system. This part allows you to reduce the effort that the driver must apply to press the pedal. The unit is installed in the engine compartment between the brake pedal and the brake cylinder.

Signs of problems at work

Malfunctions of the vacuum amplifier and the components that ensure its operation are sure to manifest themselves, and quite clearly.

If the vacuum reservoir does not function, this will be accompanied by a “stiffness” in squeezing the pedal.

If this element completely fails, it is very difficult to press the brake pedal (to verify this, it is enough to press the pedal 4-5 times with the engine not running; on the last squeeze, the resistance will be very high).

Since the vacuum is taken from the intake manifold, the loss of tightness of the vacuum booster may be accompanied by a change in engine operation during braking (although this should not happen).

Moreover, in some cases, the speed of the power plant may drop when you press the brake pedal (even to the point of stopping the unit), while in others, the speed increases.

Everything is simple here - if there is a leak in the vacuum seal, air will leak into the manifold, which affects the proportions of the air-fuel mixture, hence the change in engine operating mode.

Another obvious sign is the appearance of hissing when the pedal is depressed. The appearance of such a sound indicates the appearance of air leaks.

As for vacuum pumps, mechanical ones can make knocking noises, and constantly (the drive rod is usually to blame for this), while in electric ones the operation noise increases, and strong heating is also possible when the motor is running (here the fault usually lies in the drive motor).

What is it, why, how does it work

VUT for VAZs is a device that is responsible for braking the car. Due to the vacuum, it helps create additional force on the brake pedal. Thus, it simplifies the operation of the braking system - the car wears out less, stops faster, and the driver needs to put in less effort behind the wheel.

But it's not that simple. On VAZ 2110 cars, brake boosters affect engine performance,

Therefore, you need to listen to their serviceability and look much more closely than to the “jamming” of other parts. At idle, the injection on this car is equal to 3-4.5 milliseconds from 7 to 12 kg of air. At the slightest violation of the mixture ratio (air, fuel and evaporation), the engine will stop working evenly and begin to stall. There will be leaks in the cylinders, due to which the spark plugs may fail, the wear rate will increase, which, in turn, will increase fuel consumption and the cash costs of maintaining the machine. And all these problems are caused by air leaks from a faulty vacuum brake booster of the VAZ 2110.

On cars of the VAZ 2110 series, a braking system is used based on diagonal separation of circuits. It works according to the following scheme:

• The first hydraulic drive circuit ensures efficient operation of the left front and right rear wheels;
• The second brake circuit is responsible for the operation of the right front and left rear wheels.

Thus, if one of the circuits fails (even while driving along the highway), the second will cope with a safe stop - the car will not spin, which significantly reduces the risk of damage to both the vehicle itself and the passengers in it.

Master brake cylinder

It is not uncommon to discover problems with the master cylinder when checking the condition of the brake assembly.

GTZ

When changing the vacuum seal, it would be logical to study the current state of the gas turbine engine and, if necessary, replace it.

Many are trying to repair the GTZ. But in practice, this only brings a temporary effect, plus you have to constantly worry whether the node will fail at the most inopportune moment. The best solution is replacement.

The replacement procedure itself is as follows.

1. Disconnect the negative terminal from the battery.
2. Disconnect the wire block from the fuel oil level sensor. It is located in the tank and is built directly into the lid.
3. Use a special wrench for brake pipes to loosen their tension. There is no need to unscrew it completely.
4. Unscrew the pair of nuts that secure the GTZ to the vacuum chamber. Only now can the brake pipes be completely unscrewed.
5. Remove the cylinder from the studs.
6. If necessary, remove the brake fluid reservoir itself at the same time. To do this, you need to carefully rock the tank and remove the leg from the bushing.
7. Assess the condition of the removed cylinder. Also be sure to check for any defects on the tank. If there are any, be sure to replace the brake fluid reservoir with a new one.
8. Armed with a new GTZ, put it in place and tighten the nuts. Fasteners can be fully tightened immediately.
9. Install the reservoir and fill it with brake fluid to the maximum mark.
10. Now a very important step is to extract air from the cylinder. To do this, you need to close the holes in the front brake pipes with your fingers. At the same time, your assistant should gently, but not sharply, press the brake pedal. This will create pressure in the system. Continue this manipulation until you feel liquid coming out of the holes.
11. As soon as the liquid flows, put on the tubes, install and fix them in place. In this case, the brake pedal cannot be released.
12. By analogy, the rear tubes are connected. When they are installed in place, there must be pressure in the system, that is, the brake pedal is pressed to the floor.

After completing the replacement of the turbocharger, do not forget to bleed the brake system according to the rules.

Disassembling the unit with the TJ tank

It is quite possible to change the vacuum seal and cylinder with your own hands. The work will take a few hours, but will save a lot of money on visiting a car service center.

Loading …

How to remove a VAZ 2110 vacuum booster: replacing VUT

Replacement does not require the use of an inspection hole or overpass. The car is placed in gear to prevent spontaneous rolling. Before starting work, prepare the necessary tools. Replacement will require wrenches, screwdrivers and a new clamp to install on the hose.

The VAZ 2110 vacuum brake booster must be dismantled in the following sequence:

1. Disconnect the battery from the power supply. Replacing the vacuum brake booster involves disconnecting the electrical wires. To avoid a short circuit, it is necessary to de-energize the system.
2. Unscrew the fastening elements of the soundproofing panel located on the partition separating the passenger compartment and the engine compartment.
3. Remove the soundproofing panel.
4. Disconnect the plug from the brake light switch. Dismantling the amplifier involves removing the bracket along with the control pedal into the engine compartment.
5. Remove the expander. There is no need to disconnect the connection pipes. It is enough to disconnect the fasteners of the container and put it aside.
6. Disconnect the electrical plug connected to the sensor.
7. Unscrew the threaded elements securing the brake master cylinder.
8. Remove the part from the seat. After disconnecting the brake cylinder, inspect its boot for damage and the presence of brake fluid leaks. If a leak is detected, the sealing collars will need to be replaced.
9. Remove the clamp and disconnect the hose connecting the fitting to the engine intake manifold.
10. Unscrew the fasteners securing the pedal assembly bracket to the body of the VAZ 2110 car.
11. Remove the vacuum brake booster along with the bracket into the engine compartment.
12. Disconnect the pushrod from the pedal. To do this you will need to remove the pin.
13. Unscrew the vacuum brake booster from the bracket.

All reasons for a hard pedal during brake system malfunctions:

1) Vacuum type amplifier limit switch is faulty. Replace!

2) The vacuum booster itself has a check valve. If it malfunctions, the pedal sticks and the valve located in it does not work. Replace!

3) The vacuum filter also becomes clogged, the pedal becomes heavy and you have to press it with great effort. The filter can be changed without any problems at the dealer or in the garage).

4) The structure of the brake system includes a special valve in its design. Its body may get stuck. It will not be possible to do without a complete replacement of the component.

5) The brake booster becomes cracked. Its integrity is damaged.

The most important organ in any car is the brake system. It must be in perfect condition, because our lives depend on it. One of the main indicators of the efficiency of this unit is the pedal, which must always differ in the state of pressing that is familiar to the foot. This rule cannot be neglected and if the slightest changes occur, adjustments or repairs must be made immediately. Below we will look at what needs to be done when the brake pedal becomes hard, does not press at all, or grabs at the very end of its stroke.

We will also pay attention to issues of self-diagnosis and study all the reasons for the failure of this mechanism.

Bleeding the system

After carrying out any work related to the replacement or repair of brake system parts, the brakes should be bled. This will remove air from the line and equalize the pressure.

Tools and tools:

• jack and wheel wrench;
• key to "8";
• rubber or silicone hose with a diameter of 6 mm;
• a small, clean, dry container (preferably transparent);
• brake fluid (to top up).

In addition to all this, you will definitely need an assistant to bleed the system.

1. Place the car on a horizontally flat surface. Loosen the nuts securing the front right wheel.
2. Raise the car body with a jack. Unscrew the nuts completely and remove the wheel.
3. Remove the cap from the fitting of the working brake cylinder.

Video: bleeding the brakes

At first glance, the process of replacing or repairing a vacuum brake booster may seem somewhat complicated. In fact, you just have to understand everything in detail, and you won’t need the services of specialists.

The effectiveness of your car's brakes is important - if the brake system does not work effectively, an accident may occur. To ensure precise brakes, a booster is installed on all modern cars; it ensures that the vehicle stops instantly when you press the pedal.

Repair of the vacuum brake booster is necessary if the brakes become “wobbly” and you have to press the pedal with great force to brake.

Node examination

The need to replace the vacuum booster on a VAZ 2109 should already be stated in the event of an increase in the force applied to the brake pedal. However, a simple check will help ensure the correctness of the diagnosis:

• turn off the engine;
• press the brake pedal 5-6 times;
• hold down the brake pedal;
• start the engine.

The identifier of a serviceable VUT is an immediate, noticeable movement of the brake lever forward.

An alternative symptom will help diagnose a unit malfunction: when the engine is running, a “hissing” can be heard under the hood in the area where the intake manifold pipeline connects to the VUT check valve fitting. Experienced specialists additionally prefer to check:

• integrity of the suitable pipe; tight fit of the main element on the fitting (hissing may appear as a result of a loose connection).

The initial stage of failure of the vacuum booster is especially clearly identified on “nines” with a carburetor power system. The brake pedal is activated, as expected, with a light force, braking is good and informative, but:

• at idle speed the engine “troits”;
• when you press the brake pedal, the idle speed stabilizes;
• after applying pressure to the accelerator in neutral gear, “dips” occur, regardless of carburetor adjustments.

If the symptoms described above are present, it is advisable to remove the pipe from the “vacuum manifold” fitting with the engine running and plug the hose with a suitable object or finger - the idle speed has returned to normal and, therefore, replacing the vacuum booster on the VAZ 2109 is inevitable. If a malfunction is detected along the way in this way, the movement should be continued with the VUT turned off: the pedal will be hard, but the information content will remain.

GTZ VAZ 2110 signs of malfunction, purpose of the device, performance check replacement

Despite the fact that these two units are inextricably linked with each other, in our material we will consider them separately.
This will allow you to understand in detail all the nuances and features of the operation and repair of the two devices. I – main cylinder body; 2 – low pressure sealing ring; 3 – drive piston of the “left front-right rear brake” circuit; 4 – spacer ring; 5 – high pressure sealing ring; 6 – pressure spring of the sealing ring;

7 – spring plate; 8 – piston return spring; 9 – washer; 10 – locking screw;

II – drive piston of the “right front-left rear brake” circuit; 12 – connecting sleeve; 13 – tank; 14 – brake fluid emergency level sensor; A – gap

Vacuum booster

The braking system of a car certainly cannot be called perfect, so it has to be supplemented with devices that help improve efficiency. One of them is a vacuum booster.

Application and purpose

Today, a vacuum amplifier is in great demand because it is highly efficient.

Its tasks are extensive, but the amplifier copes with them all perfectly:

• The degree of resistance of the brake pedal increases;
• Reduces the load on the brake system;
• Acts as a highly efficient auxiliary unit;
• Has a positive effect on the service life of the brake system, etc.

This element has the following components:

• Dense body, for the manufacture of which a high-strength polymer is used;
• The diaphragm, which is also called the collecting node;
• Monitoring or control specialized valve;
• Pusher. It allows you to return the engine elements to their original position when there is no power;
• Main piston rod of the brake system cylinder (main);
• Switch return spring.

The body of this spring has two cellular divisions, which are divided into vacuum and atmospheric. Cells are often called chambers.

1. The vacuum chamber is a cell directly connected to the brake master cylinder.
2. The atmospheric chamber is a cell located opposite the brake pedal. Its open part of the body rests on the brake pedal.

It is also worth noting the diaphragm, which performs two very important tasks:

• Corrects the position of the piston in space;
• Pumps brake fluid to the main brake cylinders.

Installing a vacuum booster involves a serious change in the sensitivity of the pedal, so it is strongly recommended not to apply a large and sudden force to it in the “first couple”. Pressing should be done carefully and smoothly.

Malfunctions and ways to check them

It is possible that you may need to replace the vacuum booster on your VAZ 2110. The cause may be various malfunctions, the characteristic symptoms of which are as follows:

• When you press the brake pedal, a hissing noise occurs, and at the same time, the engine speed often increases;
• The car starts to shake;
• Spark plugs stop working efficiently;
• Fuel consumption increases noticeably.

Before replacing the vacuum booster on a VAZ 2110, it should be checked.

This procedure is performed as follows:

• As with normal bleeding of brakes, with the engine not running, press the gas pedal several times;
• After 5 or 6 presses, keep the pedal in the down position, resting it on the floor, and start the engine;
• After starting, the pedal itself will move forward a little.

There is also a high probability of damage to the diaphragm, on which a hole is formed over time. You can purchase the diaphragm with a repair kit, the cost of which is no more than 500 rubles.

Replacement

To replace an element, you need to understand the main issue - how to remove the vacuum booster from a VAZ 2110. Directly replacing the old element with a new one will not be difficult, just like the reassembly process.

Therefore, we will tell you about the main thing - dismantling the amplifier. Let's start with the fact that the procedure is not complicated, but it requires accuracy and sequence of steps. If you follow the recommendations, the work will take little time and will not take much effort.

1. Disconnect the block with wires, which includes brake fluid level sensors in its design.
2. Hold the booster check valve with one hand and carefully disconnect the hose with the other. It is advisable to disconnect the hose with a strong hand, since this will require a lot of force.
3. Remove the two bolts connecting the booster and master cylinder.
4. Carefully remove the cylinder from the amplifier.
5. There is no point in disconnecting the brake lines.
6. Give access to the dashboard, which will allow you to unscrew the nuts holding the brake pedal bracket. There should be 4 of them.
7. It is recommended to dismantle the bracket and amplifier through the engine compartment, since there is enough free space for such manipulations.
8. Remove the pin lock plate. To do this, pry the finger with a screwdriver and squeeze it out.
9. Now you can easily disable the brake pedal and booster.
10. To disconnect the amplifier and bracket, you will have to unscrew the two nuts on the mount.
11. A new one is installed in place of the dismantled old vacuum amplifier, and the reassembly procedure is performed in strict sequence of the dismantling process.

Wear and other disc defects

There are several types of wear on brake discs that can cause a hum to be heard under the described conditions. The first of them is the so-called furrows. They are clearly visible to the naked eye, sometimes even directly through the rims. They appear there for all sorts of reasons. The most obvious is any abrasive getting between the pads and rotating discs. Coarse dust, sand, dirt, small pebbles. All this can “register” water circles on disks.

The second type of excavation is a protruding edge. This defect usually leads to a hum when you press the brakes when the pads are changed. Very often these parts are purchased the wrong size, which, however, does not interfere with their successful installation. As a result, the pads do not contact the discs correctly, can overheat, wear unevenly and bite each other.

Which of these causes the buzzing doesn't really matter

The next defect is corrosion. It is observed in the form of small pits directly on the working surface of the disks. At a certain degree of severity, it can also cause brake noise. Again, the root cause is overheating under load. Parts overheat, a hum occurs, and braking performance may deteriorate.

The next possible problem with discs is when they are burnt or set on fire. These can be identified by blue or iridescent spots directly on the work surface. They say such “burns” mean that the brakes have been overloaded once or repeatedly. As a result, you should look for inadequate wear or deformation. In any case, this may well be the reason why the brakes are buzzing.

In all of these situations, the “treatment of the disease” is the same. This is a replacement brake discs. It should also be understood that after working together with defective discs, the pads are also very likely to become unusable. There is no point in using them with new disks. It is better to immediately replace with new ones. Fortunately, even if they are of high quality, these consumables do not cost a fortune.

It’s probably worth saying a few words about turning discs, which many car enthusiasts resort to. This repair method is justified, unfortunately, only in 1 case out of 10. And even then, if the groove was entrusted to a competent turner, and they did not try to “align” the disc with a grinder directly on the machine. The latter is strictly not recommended. The brake system is a mechanism that does not forgive inaccuracies. And the grinder and accuracy are antonyms.

Common breakdowns of VUT VAZ 2106 and their symptoms

Since the vacuum brake booster has a simple mechanical design, it rarely breaks down. But when this happens, it is better not to delay repairs, since driving with a faulty braking system is unsafe.

Breakdowns

Most often, the “vacuum tank” becomes unusable due to:

• violation of the tightness of the hose connecting the inlet pipe of the manifold and the VUT;
• check valve passage;
• rupture of the diaphragm cuff;
• incorrect adjustment of the rod protrusion.

Signs of a faulty VUT

Symptoms that the amplifier is broken may include:

• dips or too tight brake pedal travel;
• self-braking of the car;
• hissing from the amplifier housing;
• reduction in engine speed when braking.

Dips or difficulty moving the brake pedal

With the engine off and the power steering off, the brake pedal should be pressed with great force, and after 5–7 presses it should stop in the upper position. This indicates that the VUT is completely sealed and all valves, as well as the diaphragm, are in working condition. When you start the engine and press the pedal, it should move down with little force. If, when the power unit is not working, it fails, but does not squeeze out when the power unit is running, the amplifier is leaky and, therefore, faulty.

Spontaneous braking of the car

When the VUT depressurizes, arbitrary braking of the machine may occur. The brake pedal is in the upper position and is pressed with great force. Similar symptoms also occur when the protrusion of the rod is incorrectly adjusted. It turns out that due to its greater length, it constantly puts pressure on the piston of the main brake cylinder, causing arbitrary braking.

Hiss

A hissing “vacuum seal” is evidence of a rupture of the diaphragm cuff or a malfunction of the check valve. If a crack forms in the rubber cuff or detaches from the plastic base, air from the atmospheric chamber leaks into the vacuum chamber. This causes the characteristic hissing sound. In this case, braking efficiency decreases sharply, and the pedal falls down.

The process of replacing vacuum on a VAZ-2114

Before replacing, you need to prepare the following tools:

1. Screwdriver.
2. Pliers.
3. Socket wrenches for 7 and 13.
4. Special wrench for unscrewing brake pipes.
5. Additionally, prepare new fittings and plugs.

Step-by-step algorithm for replacing a part:

When dismantling the VUT, you will obviously be in the way of the brake cylinder, which is better to remove from the very beginning or disconnect the fittings from it and move it to the side. The cylinder is not the most important obstacle. The next step is to unscrew the VUT fasteners, which is not entirely easy to do and is also inconvenient. Start with the valve. Remove the hose clamp, remove the support sleeve and pull out the brake pin. Take a 14mm wrench and unscrew the 4 amplifier mounts. After removing the part, prepare to install the new device on the car. First of all, install a special fixation frame on the VUT, which will need to be tightened with a 7 key, and only then install this element on the VAZ. The assembly sequence is quite simple

Please note, from the point of view of convenience, first of all, the brake pedal and booster are connected using a finger, and then the unit is mounted in the car.

As a recommendation, when replacing the vacuum booster, you can also replace the hose. This element is also subject to wear and tear, which sometimes affects the performance of the new device.

Repair or replacement

Having discovered a faulty vacuum brake booster, you can go in two ways: replace it with a new one or try to repair it. It should be noted here that a new VUT without a master brake cylinder will cost approximately 2000–2500 rubles. If you don’t want to spend that much money and are determined to repair the unit yourself, purchase a repair kit for the old “vacuum unit.” It costs no more than 500 rubles and includes those parts that most often fail: cuff, shank cap, rubber gaskets, valve flanges, etc. Repairing an amplifier itself is not a very complicated process, but it is time-consuming. It involves removing the device from the car, disassembling, troubleshooting, replacing faulty elements, as well as adjustment.

Change the vacuum booster or repair it, the choice is yours. We will consider both processes, and start with replacement.

Replacing VUT with VAZ 2106

• thin slotted screwdriver;
• spanner set to “13”;
• socket wrench set to "13".

1. Place the car on a flat surface and put it in gear.
2. In the interior, we bend the carpet under the pedal bracket. We find there the junction of the brake pedal and the booster pusher.
3. Using a slotted screwdriver, remove the spring retainer from the pedal mounting pin and the pusher shank.

After replacing the device, do not rush to install the master brake cylinder, since before this it is necessary to check and, if necessary, adjust the protrusion of the rod, which we will talk about after considering the VUT repair process.

Video: replacing VUT

Repair of the VAZ 2106 vacuum cleaner

• vice;
• slotted screwdriver;
• small hammer;
• pliers.

1. We fix the vacuum booster in a vice in any convenient way, but only so as not to damage it.
2. Using a slotted screwdriver and pliers, we flare the halves of the device body.

Repair of vacuum brake booster VAZ 2109

The main sign indicating to the driver that the vacuum booster is faulty is difficult movement of the brake pedal, which in turn affects the quality of braking and, as a consequence, the safety of driving. Vacuum amplifiers can only be repaired using special equipment; if you don’t have such equipment, you will have to replace it completely, but before that you need to check the quality of its operation and the operation of the check valve, and only after that make a decision about either replacement or repair.

To check the operation of the vacuum booster, press the brake pedal several times, creating pressure in the system, and the brake pedal should lock in the upper position. Now, without releasing the pedal, start the engine. At the moment of startup, if the amplifier is working properly and the tightness of the connection of the vacuum hoses is not broken, the pedal will go down. If it does not go down, then first of all we check the quality of the connection of the vacuum hose and the tightness of the check valve.

To check the check valve on a VAZ 2109 car, you need to do the following sequence of actions:

First of all, as mentioned above, we check the tightness of the connection of the hoses with the fitting on the inlet pipe and the check valve on the amplifier.

• Next, you can start checking the valve itself, first disconnect the hose from it and pry it off with a flat screwdriver, remove it from the amplifier.
• In the next step, we will need any rubber bulb, the only two conditions: the bulb must be sealed and it must fit the diameter of the valve fitting. A hydrometer is quite suitable for this role.
• Having pulled it onto the fitting, we squeeze the bulb with our hand, thereby releasing air through the valve and releasing it. If the bulb remains compressed, then the valve is working properly, that is, it holds the vacuum. Otherwise, it must be replaced. As an option, you can try to blow out the valve with your mouth, that is, first we blow it out, so the air should come out freely, and then we suck it in and, as a result, the air should not pass through.

This completes the process of checking the vacuum booster and check valve of the VAZ 2109. If the tightness of the hoses is not broken, and the valve itself is working properly, then you will have to change the amplifier.

Brake booster

Almost all modern cars are equipped with vacuum brake boosters. They have a fairly simple design, but are very effective and quite reliable.

Purpose

The VUT serves to transmit and increase force from the pedal to the brake master cylinder (MBC). In other words, it simplifies the driver’s actions when braking. Without it, the driver would have to press the pedal with incredible force to force all the working cylinders of the system to function simultaneously.

Device

The VUT design consists of:

• housing, which is a sealed metal container;
• check valve;
• plastic diaphragm with rubber cuff and return spring;
• pusher;
• follower valve with rod and piston.

A diaphragm with a cuff is placed in the device body and divides it into two compartments: atmospheric and vacuum. The latter is connected through a one-way (non-return) valve to a source of air vacuum using a rubber hose. In the VAZ 2106, such a source is the intake manifold pipe. It is there that, during operation of the power plant, a vacuum is created, which is transmitted through a hose to the VUT.

The atmospheric compartment, depending on the position of the follow-up valve, can be connected both to the vacuum compartment and to the environment. The valve is moved by a pusher, which is connected to the brake pedal.

The diaphragm is connected to a rod, which is provided to push the master cylinder piston. When it moves forward, the rod presses on the GTZ piston, causing the fluid to be compressed and pumped to the working brake cylinders.

The spring is designed to return the diaphragm to its initial position upon completion of braking.

How it works

The functioning of the “vacuum tank” is ensured by the pressure difference in its chambers. When the car engine is turned off, it is equal to atmospheric pressure. When the power plant is running, the pressure in the chambers is also the same, but there is already a vacuum created there by the movement of the engine pistons.

When the driver presses the pedal, his force is transmitted to the follower valve through the pusher. Having shifted, it closes the channel that connects the compartments of the device. The subsequent stroke of the valve equalizes the pressure in the atmospheric compartment, due to the fact that the atmospheric channel opens. The pressure difference between the compartments causes the diaphragm to bend, compressing the return spring. In this case, the rod of the device presses on the GTZ piston.

The force created by the “vacuum driver” can exceed the driver’s force by 3–5 times. Moreover, it is always directly proportional to the applied.

Location

VUT VAZ 2106 is installed in the engine compartment of the car on the left side of the engine shield. It is secured with four studs on the plate of the brake and clutch pedal bracket. The GTZ is fixed on the body of the “vacuum generator”.

Disassembling vacuum booster 2109

It is not difficult to disassemble VUT 2108-2109, but for disassembly it is necessary to fix the device. We disassemble the node in the following order:

• clamp the “vacuum sealer” in a vice;
• using a screwdriver on the body, we bend the grooves with which the two halves are held together;
• when almost all the rivets are straightened, it is necessary to hold the outer part of the body - a spring is installed inside the device, and it can shoot. If the old diaphragm is put back into place, there is no need to push the screwdriver far inward, as the rubber seal may be damaged;
• remove the rubber covers from the fastenings (2 pcs.);
• dismantle the plastic casing together with the diaphragm and pusher assembly;

Typically, the repair kit for the VAZ-2109 vacuum amplifier contains a diaphragm, a cuff, a boot, covers (2 pcs.) and a valve. All parts should be changed so that you don’t have to redo the work later. When assembling a vacuum amplifier, it is better to immediately fix the diaphragm on a plastic casing, this will make it easier to mount the unit.

It doesn’t matter which side the spring is placed on, but when assembling the amplifier, you will have to make an effort to get the holes in the housing onto the studs.

Removing the vacuum booster 2106-07

Removing the VUT on a VAZ classic car is quite simple, and if you have minimal plumbing skills, this work is not difficult to complete. We remove the unit as follows:

• we turn off the engine, disconnect the main brake cylinder (GTC) from the “vacuum chamber”, the cylinder is held on by two nuts. There is no need to disconnect the brake pipes and hoses from the turbocharger; we simply move the cylinder to the side;

• we pull the hose off the check valve, while holding the valve so as not to pull it out and break it;
• in the cabin, remove the fixing bracket on the brake pedal and release the VUT pusher;

• then in the cabin we unscrew the four nuts that hold the “vacuum unit”, dismantle the unit - it is removed in the engine compartment.