VAZ 2114: replacing the vacuum booster - instructions with photos and videos

The vacuum brake booster of the fourteenth is a casing with a valve inside. It is divided into two parts by a rubber layer - a diaphragm - one part is atmospheric, and the second represents the vacuum space, which is connected to the intake pipe from the engine.

Vacuum booster

The amplifier valve is a plastic casing that contains the main parts that are subject to wear and cause trouble for the driver in the form of gearbox rattling. The composition is as follows: on the support bushing there is a rod, which is adjacent to the piston and its own buffer. Actually, the valve itself is on its pusher and return springs along with the filter.

The vacuum booster functions as follows: you press the brake to the floor, at this time the piston and valve pusher move in such a way that this opens the space between the two compartments of the unit. Then, a vacuum compartment moves into this space and takes in air. Air presses on the damper between the two parts of the amplifier, creating different levels of pressure in one and the other part. Due to this difference, the valve itself and the rod move, respectively. By lowering the pedal, all parts return to their places, the system ceases to function.

As with all parts of the system of any car, repair of the vacuum brake booster is inevitable. In order to decide on the repair work - whether it will be a DIY garage repair or whether you should go to a service center - you must first determine the signs of a malfunction in the VAZ 2114 vacuum brake booster.

How to check the vacuum booster?

The first cause for concern will be tight pedal pressure and poor brake performance. At idle, when you press the brake pedal, does the engine speed drop or increase? Most likely, the fault lies in the VUT.

There are several ways for self-diagnosis:

It is necessary to turn off the engine, start pressing the brake pedal (5-6 times), then fix it in the pressed state. We start the engine and at this moment the pedal should go down 2-3 cm and remain in that position. If it goes to the floor, then the vacuum seal is faulty.
The engine should run for 2-3 minutes after starting. Then turn off the car and press the brake 3 times. If the pedal is soft on the 3rd press, then the VUT is faulty and there is an air leak somewhere.
With the engine running, press the brake pedal all the way and hold it. After turning off the engine, keep it for about 1 more minute; if the pedal does not begin to press on your foot in an attempt to rise up, then the VUT is operational. Also, when pressed there should be no hissing sounds of air.

Useful : Replacing brake fluid on a VAZ 2114

When you have carried out diagnostics and discovered one of the listed reasons, it is better to immediately engage in repairs. At some point, due to a malfunction, you may have too tight a brake or lose it completely, and you won't be able to maneuver quickly when you need to. Thus, you can create an emergency situation or harm someone.

Functionality check

This instruction will be relevant when checking the vacuum booster on VAZ models from 2113 to 2115. So the technique is clearly universal.

Press the brake pedal all the way to the floor about 4-5 times. In this case, the engine should not be started. Due to these presses, you will create equal pressure in two sections of your vacuum booster. The valve will report problems as soon as you start pressing the pedal. If you hear squeaks while pressing, this indicates a serious malfunction.
Once the pressure is even, start the engine while keeping the brake pedal to the floor. If the brake booster system is working properly, then the pedal will rise by itself after the engine is started. If this does not happen, then you will definitely have to face repair work.
If the check shows problems with the amplifier, do not forget to additionally check the quality of the hose fastening and the condition of the flange. When the mount is abnormal, this may result in the brake pedal not lifting.

We recommend: How to properly bleed the brakes of a car with ABS?

Sometimes poorly fixed fasteners cause quite expensive and actually unnecessary repairs or replacement of the vacuum booster. Conduct a preliminary check so as not to complicate your life.

When to change the amplifier

Brakes are a whole system that consists of many elements. Each of them must function correctly and efficiently.

In addition to checking the vacuum booster itself, you should inspect the condition of the brake fluid pipes, make sure there are no brake fluid leaks, and look at the current condition of the brake pedal.

If no faults were found in the braking system, you can think in more detail about the issue of replacing the vacuum booster.

There is no point in repairing the element. It's easier to start replacing right away. The functionality of the car and the power that your engine is capable of producing depend on the quality and timeliness of the work performed. Lack of power negatively affects the speed and comfort of movement around the city and beyond.

Replacement

To replace a vacuum booster you will need a certain set of tools and materials. It includes:

Screwdriver Set;
Pliers;
Socket wrench for 13 and 17 millimeters;
Special wrench for brake pipes;
New plugs;
New fittings.

Replacement procedure

Let's get straight to work.

Removing the vacuum booster can be difficult due to the brake cylinder. Therefore, we advise you to remove it first. Another option is to disconnect the pipes from the brake cylinder and move them to the side for a while. Here you decide for yourself what is more convenient for you.
The cylinder is not the main problem. It is difficult to cope with the mounting of the vacuum booster. It's just not very convenient to do this. This is the design of the VAZ 2114.
Start with the valve - remove the hose fasteners from it, remove the support bush, after which you can pull out the brake pin.
Next, using a 13 mm wrench, all four fasteners of the vacuum booster are dismantled.
After all the inconveniences of the work done, you can remove the element and get ready to install a new amplifier in its place.
To do this, you will have to install a special mounting frame. The frame is tightened with a 17 mm wrench, after which the new component is installed inside the car.
If you want to make your work as easy as possible, do not forget to first connect the brake pedal to the booster with your finger when reassembling it. After this, it is much easier to cope with putting the vacuum seal back into place.

When replacing the vacuum booster, be sure to change the old vacuum hose at the same time. This element is far from eternal, therefore, as it wears out, it will negatively affect the quality and efficiency of the new vacuum seal.

Necessary tool

If you decide to do the repairs yourself, it is better to approach the process carefully. Collect all the necessary tools from the list:

Screwdriver Set;
Pliers;
Collar;
Extension;
Kardanchik;
Socket head 13;
Open-end wrench for 10 and 13.

In addition, you should keep a container of brake fluid on hand. You may need to top it up after installing a new part. Also choose a suitable place for repairs; it is best to do this indoors, where weather conditions will not interfere with you. Let's look at the question “how to replace the vacuum booster on a VAZ 2114.”

Also check out

It is often recommended to disconnect the tubes that complicate the process of removing the VUT, but you can do without this.
Three of the four tubes coming from the brake cylinder make it difficult to remove the cylinder. To dismantle the cylinder, you can unscrew only one nut to “10”.

Disconnect the hose that goes from the intake manifold to the vacuum booster valve.

Remove the mounting bracket. It is better to use a special cardan (its image is in the photo). The VUT itself is attached to the body with four turnkey nuts “13”.

Move the mounting bracket to the new vacuum brake booster (you will need to unscrew a couple of nuts to “17”).

Reassemble in reverse order.

Replacing the vacuum booster on a VAZ 2114

The entire process of replacing the vacuum seal on a VAZ 2114 takes place in the engine compartment according to the following points:

To access the VUT fasteners, we need to remove the air filter housing.
We also loosen the adsorber clamp and move the mechanism to the side without disconnecting the hoses.
Now you can unscrew the two nuts securing the expansion barrel. This is done with a key of 13.
Remove the pipe from the check valve flange.
Now we unscrew the amplifier itself. It is attached to the body with 4 nuts; it is convenient to unscrew them using a wrench, an extension and a cardan. We do this with a 13mm head.
Remove the spring clip from the pin securing the vacuum seal to the brake pedal and disconnect the mechanism.
We take out the VUT by pulling it towards ourselves.
Remove the bracket that secures the element to the car body.
Read also: Replacing steering rods and ends with your own hands is within the power of every driver if desired

At this point, the dismantling process is completed; installation occurs in the reverse order. The most important thing during installation is to install the rod evenly so that it immediately fits onto the pedal, and fasten the pin from inside the car.

Purpose and location of the unit

The first classic Zhiguli models (VAZ 2101–2102), produced without amplifiers, were distinguished by a “tight” brake pedal. To stop the car suddenly, the driver had to exert considerable effort. In the 70s of the last century, the manufacturer began equipping cars with vacuum boosters (abbreviated as VUT), which significantly increased braking efficiency and made the driver’s work easier.

The unit in the form of a metal “barrel” is installed on the bulkhead between the engine compartment and the interior of the VAZ 2107, on the driver’s side. VUT attachment points:

the body is screwed to the partition with 4 M8 nuts;
the master brake cylinder is attached to the booster in front on 2 M8 studs;
the push rod of the element goes inside the passenger compartment and is connected to the brake pedal lever.

The vacuum booster of the brake system is located on the wall of the partition between the passenger compartment and the engine compartment

The booster's job is to help the driver apply pressure to the master cylinder rod using vacuum force. The latter is created using vacuum taken from the engine through a special pipe.

The vacuum selection hose is connected to the intake manifold from the side of the channel leading to cylinder III. The second end of the pipe is connected to the fitting of the check valve installed outside the VUT housing.

The VUT vacuum pipe (on the left in the photo) is connected to the fitting on the suction manifold

Essentially, the vacuum booster does the physical work for the driver. The latter only needs to lightly press the pedal for the car to begin to slow down.

Signs of a faulty vacuum brake booster

When understanding the signs of a faulty vacuum brake booster, it is worth noting that its failure can be caused not only by the membrane, but also by adjacent components. Therefore, when a malfunction occurs, each component of the system must be checked. When the VUT fails, the following symptoms can be observed:

The engine started to stall. This occurs due to air leaking through the system;
The efficiency of the braking system has significantly decreased;
The brake pedal is pressed with great force;
A knocking sound is heard when braking hard;
When you press the pedal, you can hear a hiss of air.

In some cases, the brake system failure indicator on the dashboard starts to light up, but this is not a clear sign of a failed VUT; the error may also appear due to a problem in other components. We talked about this in this article.

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):

The body is cylindrical in shape.
Pressure rod of the main brake cylinder.
A cover connected to the body by point rolling.
Piston.
Bypass valve.
Brake pedal pusher.
Air filter.
Buffer insert.
Internal plastic housing.
Rubber membrane.
Spring for return of the inner housing with membrane.
Connection fitting.
Check valve.
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:

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.
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.
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

Service replacement cost

You may not be able to change the part yourself because you don’t have enough tools, knowledge, or a place where you can do it. In this case, you can contact a car service; the repair price will be around 1000 rubles, taking into account the average prices in Russia. In this case, the total repair budget will be around 3,000 rubles , unless replacement of additional elements is required. There is one important advantage when contacting a service center. When people who know their stuff work there, they will be able to identify other shortcomings of the system during the analysis and show them to you clearly so that you know exactly what you are paying for. Remember that repairs should be made immediately when the problem is diagnosed, since driving with a broken vacuum booster is very dangerous. For this repair you do not need special knowledge, so you can easily replace the vacuum booster yourself, saving a third of your budget.

Unit repair - diaphragm replacement

This operation is unpopular among Zhiguli owners; usually car enthusiasts prefer to change the entire amplifier. The reason is that the result does not correspond to the effort expended; it is easier to buy and install the VUT assembled. If you definitely decide to disassemble and repair the vacuum amplifier, prepare the following tools and consumables:

assembly spatula, powerful flat screwdriver;
pliers;
hammer;
brush with metal bristles;
large bench vice;
repair kit for vacuum amplifiers VAZ 2103—2107;
silicone sealant.
When replacing a damaged diaphragm, it is recommended to change all VUT rubber products - the rod seal and O-rings
Read also: Lambda probe Lada Kalina: Purpose, Location, Error

It is best to buy a repair kit from the Balakovo Rubber Products Plant. This company is a direct supplier of parts for AvtoVAZ and produces high-quality original spare parts.

To carry out repair work, the VUT must be removed from the vehicle, as described in the instructions above. Disassembly and replacement of parts is carried out in the following order:

Place a mark on the body with a marker, flare the connections with the cover, bending the edges of the shell with a mounting blade.
The mark is necessary for assembling the amplifier in order to correctly align the cover with the body
Carefully separate the elements, holding the lid with your hands, as there is a large, powerful spring installed inside.
Remove the rod and seal, remove the diaphragm from the inner housing. When disassembling, lay out all the parts one by one on the table so as not to confuse anything during the installation process.
To avoid confusion, it is better to lay out all VUT parts on the table during disassembly.
Clean the housing and the membrane contact areas with a brush. If necessary, dry the inside of the chambers.
Reassemble the vacuum booster elements in reverse order, using new parts from the repair kit.
Before assembly, the new membrane is stretched onto the plastic body
Aligning the marks on the cover and body, insert the spring and compress both halves in a vice. Roll carefully using a pry bar, hammer and screwdriver.
If desired, the repaired VUT can be painted using an aerosol can.
Check the tightness of the VUT using a rubber bulb inserted into the hole in the vacuum hose.

After assembly, install the unit on the car, having adjusted the rod extension in advance (the procedure is described in the previous section). When finished, check the operation of the amplifier while running.

Video: how to change the VUT diaphragm on a “classic”

Vacuum brake boosters rarely bother Zhiguli owners with breakdowns. There are cases when the factory VUT worked properly throughout the entire life of the VAZ 2107. If the unit suddenly fails, there is no need to panic - a malfunction of the vacuum booster does not affect the operation of the brake system, only the pedal becomes hard and uncomfortable for the driver.

Checking the serviceability of the amplifier

In this section we will tell you how to check the performance of the vacuum brake booster on a VAZ-2114.
All of the recommendations given can be used when checking the unit, both on the thirteenth and fifteenth car models. To check, follow these steps:

Press the brake pedal all the way about 5 times with the engine off. This action will create uniform pressure in both components of the VUT. When the brake is pressed, the valve will immediately release itself. If you notice a squeak, this is a clear signal that the part needs to be replaced.
As soon as the pressure is uniform, you need to start the car while holding the brake pedal to the floor. If everything is fine with the unit, the pedal will rise after starting the internal combustion engine. Otherwise, repairs will need to be made to replace the device.
When you have already realized that the part needs to be replaced, you need to additionally check how well the hose is fixed, as well as the condition of the flange. If these elements are in a condition that does not meet the standard, this may affect the performance of the amplifier. Accordingly, in this case, you may need to tighten the fastenings and the problem will solve itself.

VUT breakdown on the road

Many people are interested in what to do if the brake booster breaks down on the road and how to get home safely. First we need to understand that the vacuum goes from the collector to the amplifier. A pipe comes from the manifold and goes to the valve, which is built into the VUT housing.

In order to eliminate the problem of floating speed due to a breakdown of the VUT, as well as ineffective braking, you need to shut off the line through which the vacuum flows. Remove the pipe coming from the brake booster from the manifold and plug the flange. This can be done using a rubber stopper.

Next, insert something into the pipe that goes to the VUT and use a worm clamp to plug it.

After you carry out the procedure described above, the speed will stop floating and the brakes will be tight, but effective with the proper force on the pedal. If you had to drive a VAZ 2101, the pedal force will be the same, since this car does not have a brake booster from the factory.

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).

Master brake cylinder

Now let's talk about the master brake cylinder on a VAZ 2110 car. If you do not want to allow the brakes to fail while driving, they should be checked periodically, and if problems arise, take appropriate action immediately.

A common reason for replacing the master brake cylinder of a VAZ 2110 is precisely the fact that the brakes are lost.

Symptoms of a problem

Of course, brakes can completely lose their effectiveness for various reasons, but now we are talking specifically about the master cylinder. If the reason lies therein, then it can be determined by the following signs:

The master cylinder shows signs of brake fluid leakage;
The pedal has an idle motion, that is, when it is pressed, no force is created;
The brake pedal simply won't press.

Replacement

The most difficult process is disassembly. Therefore, let's talk about it in more detail.

Carefully disconnect the master cylinder from the pipeline. Disconnect the block, which is equipped with wiring, from the emergency brake fluid indicator. The connection to the “ten” is made by terminals. Cover the pipe and assembly openings with something to prevent brake fluid from leaking. It will pollute the interior space, which is undesirable. Now remove the cylinder along with the reservoir. To do this, simply unscrew the fastening nuts that connect the element to the vacuum booster. After removing the brake fluid level sensor, drain the brake fluid present from the cylinder and the cylinder itself. If there is no serious need, you should not remove the tank. But for complete assembly, the tank is removed and then installed in place in strict order. Before reassembly, each element is washed with purified brake fluid.

A good alternative is isopropyl alcohol. Do not forget to dry the parts with a compressor and wipe with a clean, dry cloth. Carefully avoid contact of the main cylinder with fuel or kerosene. Pay special attention to the O-rings. If you wash them with special alcohol, do not keep the rings in this liquid for more than 20 seconds.

After processing, immediately dry and wipe the seals. Treat the surface of the piston and mirror to remove all rust. When replacing the master cylinder, new O-rings must be installed, regardless of their current condition. Check the elasticity of the piston springs under load. Refer to the VAZ 2110 repair manual, which indicates the appropriate loads and forces for testing. When free, the length of the spring should be 59.8 millimeters. If the indicator deviates from the norm, be sure to replace the springs.

https://youtube.com/watch?v=gYLFHjMr2Fk

Leveling up

If you think that after replacing the brake master cylinder you can safely go out on the roads, then you are mistaken. In fact, a complete repair of brake cylinders on a VAZ 2110 includes bleeding.

The procedure is not complicated, but requires following the instructions.

Find someone who will help you in this matter. One will be near the car, and the second will be directly in the cabin.
Inflate the brake pedal by pressing it several times.
The assistant presses the pedal, and meanwhile you slightly unscrew the fitting on one of the brake system pipes.
This should release air, as well as a small amount of brake fluid. Don't be alarmed by leaks, this is completely normal.
Retighten the fitting using the same wrench as when unscrewing - 10.
Command your assistant to lower the part.
The procedure is repeated until air bubbles begin to come out when unscrewing the fitting.
Each of the four circuits is pumped using similar actions.
First make sure that the brake fluid in the expansion tank is filled to the required level.

Actually, at this point the repair work related to the master brake cylinder can be considered complete. Experience in operating a car like the VAZ 2110 suggests that you should always store a container of brake fluid in the trunk. All sorts of situations happen on the road, and you need to be prepared for them.

Unit cost

It is better to find out how much a vacuum brake booster for a VAZ 2114 costs directly from the stores. Since the regions are different, the price categories are different and it’s easier to navigate the area locally. The approximate cost is from 2,000 to 3,000 rubles. Installing it in the service will cost a third, or even half, of the cost. Despite the inaccessibility of the unit and some inconvenience, it is much easier to change the amplifier yourself. The frequency of breakdowns or replacements directly depends on the quality of the track, driving style and the general wear and tear of car parts, in particular the chassis. Therefore, it is difficult to say that there is any specific regulatory period. The only thing you need to remember is about timely diagnosis: sometimes it’s worth getting confused and going over your fourteenth with the eye of a caring owner. And, of course, you shouldn’t delay repairing or replacing the unit.

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