How to replace a rear brake cylinder yourself

Replacing the master and working brake cylinders on VAZ cars

The effectiveness of a car's brakes depends on the condition of all its elements, and if there are any signs of malfunction in the brake system, repairs must be made.

Replacing a brake cylinder is a simple job, but extremely important; driving with faulty brakes is strictly prohibited. Diagnostics and repair of the brake system (TS) must be carried out in a timely manner; traffic safety depends on the serviceability of the brakes.

Examination

You should make sure that the master cylinder is the culprit for the malfunction of the brake system. This is easy to do; you don’t even have to go to a service center and spend money on it.

Unit location

1. Press the brake pedal with the power unit off.
2. Start the engine without taking your foot off the gas pedal.
3. During normal operation, the gas turbine engine fails under the influence of vacuum.
4. If the pedal does not fail, you will need to conduct more thorough diagnostics and restore the device to functionality.

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Most likely, you will need to restore the tightness of the return regulator connection. It is located on the intake manifold amplifier housing.

Repair kit or new GTZ?

Many car owners face a question when the brake master cylinder fails: how exactly to repair the brake master cylinder. After all, there are two main options:

• Purchase a new GTZ;
• Use repair kit.

First, let's take a look at the price tags.

Purchasing a repair kit and using it to restore the functionality of the brake cylinder entails uneven wear of old and new elements, breakage of rings and a number of other problems. In this regard, we advise you to eliminate the breakdown by completely replacing the gas turbine engine, and not by using a repair kit.

The device of the VAZ brake system

The brake system of Togliatti-made cars is quite simple; the vehicle consists of the following main parts:

1. pedals, which are pressed to achieve braking;
2. brake master cylinder (MBC), it transmits the force of pressing the pedal through hydraulics to the working cylinders, respectively, to the wheels. GTZ VAZ - dual-circuit, the circuits are divided to transmit fluid pressure to the front and rear wheels;
3. a vacuum booster that makes it easier to press the pedal;
4. tubes that connect the elements of the vehicle;
5. brake working cylinders (RTC);
6. pads (drums) and discs;
7. brake distributor (pressure regulator).

When you press the brake pedal, the piston in the brake fluid compressor compresses the brake fluid and transmits its pressure to the brake pedal. The pistons of the working cylinders are expanded under the influence of hydraulics, moving the pads towards the discs or drums. The movement of the wheels slows down, and thus the car slows down.

Symptoms of a problem

With a calm driving style and regular maintenance of the brake system, the GTZ will serve without interruption for many years. Cylinder output increases with frequent vehicle use in city traffic.

Useful : Replacing brake hoses on a VAZ 2114

Frequent and prolonged stops accelerate the wear process of the turbocharger, which is reflected in the manifestation of the following symptoms:

• When you press the brake pedal, the car stops slowly, although the fluid level and the condition of the discs and pads are normal;
• To effectively brake, you have to press the pedal with serious force;
• Short brake pedal travel is another sign of a worn cylinder;
• Sudden failure of the pedal and “grabbing” of the brake at the end of pressing;
• Incomplete disengagement of the calipers, which leads to friction of the pads on the discs.

The listed symptoms of a faulty master cylinder manifest themselves in different ways, but always mean there are problems with the braking system. The braking system in your car requires regular maintenance. Despite the simplicity of the design and reliability, diagnostics of the design should be carried out every maintenance. Regular replacement of pads, installation of new brake discs, replacement of fluid, elimination of leaks from pipes - all this ensures the smooth operation of the system as a whole. The GTZ plays a crucial role in this design, because Braking efficiency directly depends on the correct operation of the cylinder. In addition to the GTZ located under the hood of the car, there are other elements in the system that are responsible for stopping the car. Often, in addition to the main brake cylinder, it is necessary to replace the front brake cylinder on a VAZ 2114. It is located on each caliper and is responsible for actuating the pads.

A faulty front brake cylinder on a VAZ 2114 leads to a wedge in the mechanism and friction of structural parts. If the front TC fails, the car begins to move to the side when braking, and extraneous noise comes from the wheel.

Malfunctions occurring in the brakes

From time to time, various malfunctions occur in the vehicle, and the working and master cylinders also often fail. The following breakdowns occur at the RTC:

1. the piston gets stuck in one of the positions;
2. the inner surface wears out;
3. The sealing cuffs fail (tear or swell).

The main sign of a faulty condition is the appearance of smudges (leaks) of brake fluid (FL) from the RTC. If the pads are worn down to bare metal, the pistons in the RTC extend too far, and as a result, the brake fluid may leak and the brakes will fail.

In the GTZ, the piston can also jam, the internal cavity of the mechanism can wear out or rust, and the cuffs can leak. Symptoms of a GTZ malfunction are as follows:

1. when braking, the brake pedal (BP) “fails”, the effectiveness of pressing disappears, this usually happens when there is a small leak from the turbocharger;
2. braking occurs at the very end of the pedal stroke, and you have to press the PT several times to brake;
3. there are no brakes on the front or rear wheels, this happens if one of the GTZ circuits does not work.

You cannot drive with faulty working and master brake cylinders; the parts should be replaced immediately.

Malfunctions

Symptoms of a malfunctioning TTS:

1. The brake fluid leaves the reservoir;
2. The rear drum is wet, fluid leakage is noticeable;
3. The braking efficiency has disappeared, the pedal “takes” at the very end of the stroke, sometimes not from the first stroke.

Reasons for inoperability:

1. Natural wear and tear;
2. The cuffs are corroded due to mixing different types of brake fluid;
3. Poor quality of the part;
4. The pistons were squeezed out due to severe wear on the pads.

It happens that the pistons inside the housing become jammed. If this happens with the pistons spread apart, the car begins to constantly slow down and the drum overheats. You cannot drive with such a defect; the car must be urgently repaired.

There is one nuance that is worth focusing on. Often, when bleeding the brakes, technicians try to unscrew the bleeder fitting on the cylinder and break off. Even WD-40 doesn't help. This happens due to the fact that over time, the “pumping” begins to boil in the ZTC body. Therefore, before bleeding the brakes, you should have a supply of new replacement parts.

There is also a tricky way that will help you avoid breaking off the fitting. Before unscrewing, you must carefully (do not break the fitting with a hammer!), but thoroughly tap the housing around the bleeder fitting and try to move it out of place.

After this, without using much effort, we try to weaken the “pumping”. Doesn't work? Then tap again. Most likely, patience will be rewarded, and problems associated with unscheduled cylinder replacement will not arise.

Replacing the master brake cylinder

Replacing the GTZ on VAZ classic cars (2101-07) is not difficult; you can do this work yourself. To perform such an operation you will need the following tool:

1. 10mm wrench (or special bleeder wrench);
2. Phillips screwdriver;
3. combination wrench for 13 (you can additionally use a head with a knob and a ratchet for convenience).

It is not necessary to use a pit or a lift to perform the work; replacement can be done outside in dry weather or in the garage. The work should be performed in the following sequence:

• unscrew the three brake pipes from the bottom of the device (key for ten);

• loosen the clamps of the two hoses (at the bottom of the GTZ), pull off the hoses;

• unscrew the two nuts securing the GTZ to the vacuum booster (you need a 13mm wrench or a socket with a wrench);

• We dismantle the part, install the new gas turbine unit in place, and reassemble it.

After the operation, you should add fluid to the vehicle reservoir, then be sure to bleed the brakes well.

Replacing brake cylinder 2114

The work of replacing the GTZ on VAZ 2108-15 models is carried out approximately the same way, there are only some design differences.

We make the replacement as follows (using the example of the VAZ-2114):

• Unscrew the four tubes on the sides (two on the left and two on the right). It is better to use a special pipe wrench; you can roll up the edges of the nuts with an open-end wrench;

• unscrew two thirteen nuts securing the GTZ to the “vacuum”;
• We remove the old spare part and install a new one, not forgetting to bleed the brakes at the end of the work. At this point, the replacement of cylinder 2114 can be considered complete.

If in the GTZ 2114 the inner surface of the cylinder itself is not yet worn out, you can replace the insides of the mechanism by installing a new repair kit. The repair kit consists of four cuffs:

1. three cuffs are the same, they are the same as on models 2101-07;
2. one o-ring 2108.

Changing the repair kit is very simple:

1. pour the liquid out of the GTZ;
2. dismantle the plastic tank;
3. unscrew the front stopper (made in the form of a plug);
4. we take out all the contents (pistons, o-rings, springs), change the cuffs, and install the entire mechanism in the reverse order. Nothing should be mixed up here, otherwise the unit being repaired will not work.

Repairing the GTZ on VAZ models is not always advisable - if the mirror surface inside the mechanism is worn out, replacing the brake cylinder repair kit will not solve the problem, the GTZ will also leak. Most often, on VAZ cars, the entire master brake cylinder is replaced - a new assembled part costs around one thousand rubles, and the repair turns out to be unjustified.

Replacing brake cylinder 2107

If the replacement operation on a VAZ classic is not performed on a car lift, it is more convenient to do the work sequentially - first on one side, then on the other side of the rear wheel. To perform the work, the vehicle must be placed on a level surface, then proceed as follows:

• We turn off the engine, set the car to speed, and put chocks under the front wheels. Don’t forget to fully release the handbrake;
• loosen the wheel nuts of the rear wheel, jack up the car and remove the wheel;
• To prevent the car from going anywhere, it is advisable to place a “tragus” next to the jack;
• remove the brake drum - use a 12 mm combination wrench to unscrew the two guides;

• the drum usually comes off tightly, so it should be tapped from behind with a hammer through a piece of wood. You cannot hit the part with an iron hammer; the drum can split;
• unscrew the brake pipe from behind the cylinder, also 2 ten bolts securing the RTC itself;

• pull out the cylinder, freeing it from the pads;

• We install the part prepared for replacement (it is important to get the pads into the slots on the RTC pistons, we fasten all the removed parts in their places;

After the work has been done, it is necessary to top up the fuel injection system reservoir and bleed the brakes.

Replacing the brake cylinder VAZ 2109

The RTC on the rear axle of the 2109 wheels is changed according to the same principle as on the VAZ classic; the wheel and drum are also removed, the tube and two cylinder fastenings are unscrewed with a ten key. It often happens that the tube and RTC bolts on the support disk boil; to remove them carefully, you need to spray the connections with WD-40, and wait 15-20 minutes before unscrewing. The brake pipe nut will be easier to unscrew if you gently tap the metal around it with a hammer. When tapping, it is important not to break the bleeder fitting.

Replacing brake cylinder 2109 is not a difficult task, and many drivers can do this work themselves.

Required Tools

In order to replace the brake cylinder you will need the following tools:

1. wheel wrench;
2. jack;
3. WD-40;
4. socket wrench 10;
5. a device for unscrewing fittings if necessary;
6. metal brush;
7. rags;
8. pliers;
9. a screwdriver or pin for tensioning the springs.

Before starting all types of work, be sure to provide a place for laying out all spare parts; when removing them, it is advisable to remember the sequence and methods of removing them. This will make the reverse process much easier. In addition, before such a procedure, it is advisable to stock up on a set of brake pads, because they still need to be changed every year depending on the intensity of driving. And besides, they don't cost that much. So, having everything listed in our arsenal, let's get to work.

Replacing the front brake cylinder

The following calipers are installed on the front wheels of VAZ cars:

1. in a VAZ classic car, two front brake cylinders (FTC) are attached to the caliper brackets;
2. on VAZ 2108-15 models, one PTC is installed on each side of the front axle.

Replacing the front cylinder 2109 is not difficult, it is also easy to do yourself:

• we put the car on a flat area (the work can be done without a pit and a lift), we put tackles under the rear wheels;
• jack up the car, take off the front wheel;
• unscrew the two caliper fasteners with a hexagon;

• loosen the brake hose nut;
• bend the locking washers on the upper and lower bolts, unscrew the cylinder fastenings to the caliper bracket
• we move the PTC to the side along with the bracket;
• disconnect the cylinder from the bracket, then from the hose so that the brake fluid does not leak; after disconnecting the PTC, it is better to immediately direct the hose upward;

• we install another, new spare part, and perform the assembly.

Replacing the brake cylinder cuff

If desired, on VAZ cars you can not change the entire rear working cylinders, but only replace the cuffs. To do this, you need to disassemble the RTC - remove the pistons and spring, remove the old cuffs from the pistons and install new ones. It is advisable to repair the RTC only if the cylinders did not last long, but they began to leak. The thing is that on VAZ cars the RTCs are very inexpensive, it is advisable to change the rear cylinders as a whole - replacing the cuffs is often unjustified.

Leveling up

After replacing any cylinder in the vehicle, it is necessary to bleed the brakes. Bleeding on any car always begins with the furthest wheel from the GTZ. On all VAZ cars, first of all, they start pumping the brakes from the rear right wheel, then move to the rear left, right front, and the front left wheel is pumped last. If the brake pedal takes at the very end or is hard, bleeding should be repeated, the work should be done according to the same scheme again.

Device

The VAZ-2115 uses a brake system in which the operating circuits are divided diagonally. This can significantly increase the degree of reliability and safety of people. In particular, the first of them controls the operation of the front right and rear left brake mechanisms. If it fails, the second circuit is switched on.

In addition, the hydraulic drive operating diagram also includes:

• vacuum booster;
• a dual-circuit regulator whose task is to maintain pressure in the brakes located behind.

A sensor is installed on the VAZ-2115 that signals a decrease in brake fluid volumes. It's mechanical. In addition, there is also a parking brake system, which, in turn, has a separate drive that blocks the rear axle if necessary.

As can be understood from the diagram, the system in question is quite complex, and from time to time certain breakdowns occur in it.

To understand what kind of problem arose at one time or another requires quite a lot of experience. However, it is not difficult to make the diagnosis yourself if you use the recommendations below.

Some tips

• If you start having problems with the brakes, first of all you need to carry out an external inspection of the vehicle: check the fluid level in the reservoir, make sure that the front/rear cylinders are not leaking. There should not even be stains of brake fluid in the brake hydraulics.
• “Brake fluid” must be filled with the same brand; it is recommended to completely replace the brake fluid at least once every two years.
• If faults are identified in the gas turbine engine, and it has already served for at least a year, it is more advisable to replace it completely than to repair it. The same can be said about the rear working cylinders.
• Before changing the turbocharger, the brake fluid should be removed from it; this operation is usually done using a syringe.
• Usually a leak in the master cylinder is not visible, but if there is any suspicion that this part is faulty, you should remove the main cylinder - there will be traces of leaks at the rear, and this indicates its faulty condition.
• If, during an external inspection, cracks were found on the brake hoses, it is better not to take risks and immediately replace the defective parts.

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Disassembly and assembly of the front brake mechanism VAZ 2114, VAZ 2115, VAZ 2113, Lada Samara 2

Disassembling the front wheel brake mechanism

Unscrewing the cylinder mounting bolt: 1 – cylinder mounting bolts; 2 – cylinder; 3 – bolts connecting the cylinder with the caliper

Details of the brake mechanism of the front wheel of Lada Samara 2: 1 – wheel cylinder; 2 – fitting for bleeding the brake drive; 3 – sealing ring; 4 – piston; 5 – protective cap; 6 – retaining ring; 7 – caliper; 8 – pad guide; 9 – brake pads; 10 – protective cover; 11 – guide pin; 12 – guide pin fastening bolt; 13 – brake hose; 14 – bolt securing the cylinder to the caliper

Disconnect the hose from wheel cylinder 2. Unlock and unscrew bolts 1 securing the wheel cylinder to the guide pins, holding the guide pin by the edge with a wrench. Remove the 8 pad guide assembly with pins. Remove the brake pads of the VAZ 2113 VAZ 2115.

Pushing the piston out of the cylinder

Remove the lock ring 6 and the protective cap 5 from the cylinder and piston. Carefully push a stream of compressed air through the fluid inlet to push the piston out of the cylinder. To avoid damaging the piston on the surface of the caliper when pushing it out, install a wooden pad under the piston. Unscrew the bleeder fitting from the cylinder body and carefully inspect the working surface of the cylinder. There should be no scoring, damage or corrosion.

Front wheel brake assembly

Assemble the brake mechanism of the VAZ 2114 in the reverse order of disassembly. In this case, it is recommended to replace O-ring 3 and cap 5 with new ones. Lubricate the cylinder mirror, piston 4 and the sealing ring with brake fluid, and apply graphite grease or Ditor grease to the surface of the piston, install the piston in the cylinder and, without removing any remaining grease, put on the protective cap 5 so that its edges fit into the groove of the piston and cylinder, then install retaining ring 6. Lubricate the guide fingers with UNIOL-1 grease (1.5 g for each finger). Tighten the bolts securing the caliper and cylinder to the pins to the torques specified in Appendix 1, then lock them. Before tightening the bolts, apply sealant to them to prevent corrosion of the threaded part of the connection. After assembling and installing the brake mechanism, restore the fluid level in the reservoir and bleed the hydraulic drive system of the VAZ 2114.