We replace brake fluid according to frequency Maintenance(cm. " "). We pump the brake hydraulic drive to remove air from it and when replacing brake fluid. If one of the circuits depressurizes, it is enough to pump only this circuit, and not the entire hydraulic drive. The order of bleeding the hydraulic circuits of the brake system does not matter. We begin bleeding the circuit from the brake mechanism furthest from the master cylinder.
To complete the work you will need an assistant, as well as a special key. on 10 mm For brake pipes, a clear vinyl tube of suitable diameter, a container for draining the brake fluid and fresh brake fluid (see " ").
Execution Sequence
1. We prepare the car for operations (see " ").
2. Remove the cap of the hydraulic brake reservoir and, if the level is insufficient, add brake fluid to the reservoir up to the “MAX” mark.
3. Remove the front right wheel (see " ") and remove the protective rubber cap from the working cylinder fitting.
4. We put a rubber hose on the bleeder fitting and immerse its free end in a container partially filled with brake fluid. Pour the liquid into a container so that during pumping you can see air bubbles coming out of the rubber hose. When using a transparent hose, there is no need to pre-fill the reservoir with brake fluid, since the movement of air bubbles in the hose can be visually assessed.
5. An assistant presses the brake pedal 3-5 times and holds it down.
6. Key by 8 mm (10 mm on cars of early releases) unscrew the bleeder fitting 3/4 turn.
At the same time, the pedal begins to move, displacing brake fluid through the hose.
7. After the pedal has moved all the way, tighten the fitting, and then the assistant releases the pedal.
Attention! When bleeding the hydraulic brakes, it is necessary to periodically check the fluid level in the reservoir and, if necessary, add it.
8. We repeat the pumping operations until there are no air bubbles in the brake fluid coming out of the hose.
9. Remove the hose and put a protective cap on the bleeder fitting.
10. Install the previously removed wheel.
11. Similarly, bleed the brake mechanism of the left front wheel and close the lid of the brake system hydraulic reservoir.
12. The rear hydraulic circuit of the brake system is pumped in the same way as the front circuit, starting from the right side of the car.
13. To replace the brake fluid with a rubber bulb, remove the used brake fluid from the reservoir and fill it with fresh one. We pump the front and rear hydraulic drive circuits until fresh (lighter and more transparent) brake fluid comes out of the working cylinder fittings.
Maintaining required brake fluid level necessary for proper operation of the vehicle's braking system. How much you need can always be found in service book, but often car owners are not used to looking into it, but act empirically or look for an answer on the Internet. It is these users that we will try to help resolve the issue. how much brake fluid do you need for replacement and which one should be poured.
– working fluid of the brake system, with its help the force created in the main brake cylinder is transmitted to the wheel pairs.
If the brake fluid level is below the minimum mark (by the way, this will be indicated by the corresponding icon on the instrument panel - a red circle with waves inside), then you need to top it up. It also doesn’t hurt to check the brake system, since a decrease in the brake fluid level may indicate a malfunction or wear. Typically in the braking system passenger car contains from 0.55 to 1.0 liters of “brake fluid”. And its specification can very often be indicated on the body of the expansion barrel or its cover.
When checking, do not forget pay attention to the color of the liquid. The new TJ is transparent with a yellowish tint. During operation, it changes its color and becomes dark, this is mainly due to the accumulation of various impurities. If the fluid has darkened, this may mean that a complete replacement is necessary and simple topping up is not enough. Experts recommend Change brake fluid approximately every 2-3 years, it is this interval that is optimal in accordance with hygroscopicity and exposure to temperature loads. For proper functioning brake mechanisms, the liquid must have a number of properties and also meet a certain standard.
Old and new brake fluid
Types and properties of fuel fluid
Any brake fluid has 93-98% of the main composition and from 2 to 7% of additives, which, in fact, are the key component for imparting the declared characteristics. In general, if you look at it this way, the properties of brake fluid depend on the combination of its components. Depending on the composition of the base, TJ is divided into 3 groups.
Types of brake fluids:
- Mineral ( mineral oil LHM). They consist of alcohol and castor oil.
- Glycolic. Developed on the basis of polyglycols and their esters.
- Silicone. Manufactured from silicon-organic polymer products.
Regardless of the type and composition, all brake fluids are divided into two classifications.
Classification of TJ:
- By viscosity.
- By boiling point:
- for “dry” liquid (without water);
- “wet”, which contains 3.5% water.
If the boiling point exceeds the permissible norm, then there is a risk of a vapor lock forming in the system (as a result of moisture evaporation), which can lead to breakdown and failure of the brake pedal.
Brake fluid standards
In practice, and in most cases, it is customary to use the American quality standard FMVSS No. 116 (Federal Motor Vehicle Safety Standard), which was developed by the US Department of Transportation (DOT for short). So, often, in modern cars, either DOT 4 is used on a glycol basis, or DOT 5.1 (including glycol and silicone compounds). But in cars manufactured more than 20 years ago, BSK or DOT 3 fluid can be used.
It is important to understand that DOT 5 fluid is different chemical composition from others, so it should never be mixed with DOT 3 or DOT 4, or used in systems designed for DOT 3 or DOT 4 fluids, to avoid damaging the brakes.
The DOT standard clearly describes such characteristics as:
DOT 4 brake fluid (meets SAE J1703&J1704, FMVSS 116, JIS K2233, ISO 4925)
- degree of viscosity;
- boiling temperature;
- chemical inertness to materials (for example, rubber);
- corrosion resistance;
- constancy of properties within operating temperatures;
- possibility of lubrication of elements working in contact;
- level of moisture absorption from the surrounding atmosphere.
According to standard FMVSS No. 116 Brake fluid options are divided into five classes, each of which is designed for a specific type of operation and even the type of brake mechanisms - disc or drum.
But you should not think that these are uniform existing standards, because in Europe there will be - SAE(Society of Automotive Engineers) J1703/1704, ISO(DIN) 4925- International Organization for Standardization, in the Middle Kingdom, Japanese - JIS(Japanese Industrial Standard) K2233. But in Russia and other CIS countries there is no single standard regulating the quality indicators of brake fluids, so manufacturers work according to their own technical conditions.
Use of DOT brake fluids
Since in many cases everyone is guided specifically by the American DOT standard, let’s take a closer look at all five of its classes:
- DOT 3– designed for low-speed vehicles with drum and disc front brakes. Boiling point 220° C.
- DOT 4– poured into the brake system of high-speed vehicles that have disc brakes installed on both axles. Boiling occurs at temperatures of 240° and 160° C.
- DOT 4+, DOT 4 SUPER– DOT 4 modifications, their boiling points are 260° C and 180° C.
- DOT 5– silicone TJ, which cannot be poured into a car with an ABS system, because it does not absorb moisture, but allows it to collect in one place. Due to the fact that the boiling point is 280°C and 180°C (for “dry” and “wet” liquids) while having low viscosity, it is usually used only in racing cars.
- DOT 5.1- For fast cars, whose brakes are often overloaded. It is more high-tech and fluid than DOT 4, but still absorbs moisture. Often recommended for use in systems with ABS and ESP. Operating temperature 270°C and 180°C.
As for the service life of fluids of various classes, it should be noted that brake fluids of the class DOT 3 have a service life of approximately 1-2 years, in its turn DOT 4 is 2-3 years, and DOT 5.1 needs to be changed once every 3-4 years. DOT 5 can be used up to 5 years.
Volume of fluid in the brake system
Mostly brake system contains from 0.55 to 1.0 liter of liquid, it depends on whether in the car ABS system, and on the size of the car. The brake fluid replacement period for most cars is 2-3 years use, or 40-60 thousand mileage. To determine a more specific interval, you need to look at a specific fluid standard and driving characteristics. For example, in sports cars the TZ is changed every 5-10 thousand.
But since the question of the required volume of brake fluid in the system and its standard is asked only by owners of ordinary cars, and not premium or business class ones, we will give specific examples for cars popular in the CIS countries.
What and how much brake fluid is in some cars
| Table of the volume of brake fluid required for replacement | |||||
|---|---|---|---|---|---|
| car model | DOT class | Required amount of fuel fluid, l | |||
| Ford Focus 2 | DOT4 | 1 | |||
| Ford Focus 3 | DOT4 | 1 | |||
| Ford Kuga | DOT4 | 1 | |||
| Chevrolet Niva | DOT4 | 1 | |||
| Chevrolet Cruze | DOT4 | 1 | |||
| Chevrolet Lacetti | DOT 4 | 0.5 a with ABS and ESP 1.0 | |||
| Kia Sid | DOT4 | 1 | |||
| Kia Rio 3 | DOT4 | 1 | |||
| Kia Rio 2 | DOT 4 | with ABS - 1-1.5 l without - 1 l | |||
| Kia Sorento | DOT 5.1 | 1 | |||
| Kia Spectra | DOT3, DOT4 | 1 | |||
| Renault Logan | DOT 4 | with ABS – 1-1.5 l without – 0.7 l | |||
| Renault Duster | DOT4 | 1 | |||
| Renault Fluence | DOT4 | 0,5-1 | |||
| Renault Sandero | DOT4 | 1 | |||
| Renault Megane 2 | DOT4 | 1 | |||
| VAZ 2107, 2109 | DOT 3 | 0,55 | |||
| VAZ 2114, VAZ 2115 | DOT 4 | 1 | |||
| VAZ 2108, 2110, 2112 | DOT 4 | 1 | |||
| Lada Kalina | DOT 4 | 1 | |||
| Lada Priora (VAZ 2170) | DOT 4 | 1 | |||
| Lada Granta | DOT 4 | 1 | |||
| Lada Largus | DOT 4+ | 1 | |||
| Daewoo Matiz | DOT 4 | 1 | |||
| Mitsubishi Pajero 4 | DOT 4 | 1 | |||
| Mitsubishi Lancer IX | DOT 3, DOT 4 | 1 | |||
| Mitsubishi Lancer 10 | DOT 4 | 1 | |||
| Mazda Demio | DOT 3, DOT 4 | 1 | |||
| Mazda 3 | DOT 5.1 | 1 | |||
| Mazda cx 5 | DOT 4 | 1 | |||
| Skoda Superb II | with ABS DOT 4 | 1 | |||
| SKODA Octavia A5 | DOT 4 | 1 | |||
| Toyota RAV4 | DOT 3, DOT 4 | 0,5 | |||
| Toyota Corolla | DOT 4 | 1 | |||
| Toyota Prado 150 | DOT 4, DOT 5.1 | 1,5-1,6 | |||
| Volkswagen Polo sedan | DOT 4 | 1 | |||
| Daewoo Nexia | DOT 4, DOT 5.1 | 1 | |||
| Hyundai Solaris | DOT 4 | 1 | |||
| Hyundai Accent | DOT 5.1 | 1-1,5 | |||
| Volvo XC70 | DOT 4+ | 1 | |||
| Nissan Tiida | DOT 4 | 1 | |||
| Nissan Qashqai | DOT 4 | 1 | |||
| Nissan X Trail | DOT 3, DOT 4 | 1 | |||
How much brake fluid is in the VAZ system
As can be seen in the TJ volume table, in cars VAZ fill standard brake fluid DOT-4, but its quantity in the brake system can be from 550 ml in the classics (VAZ 2107), up to 1.0 liters in more modern domestic cars, such as VAZ 2110 or Kalina. But if you replace the TJ with flushing, then you should take 1.5 liters, and since there is no such packaging, you will have to buy two liter bottles.
However, remember that when opened, the shelf life of brake fluid is limited to two years.
Which brake fluid is better
Brake fluid has a significant impact not only on the condition of the braking system, but also on its effectiveness. The most important criterion when choosing a suitable TZ will be compliance with the necessary properties and requirements. But usually on the packages different manufacturers everything is very beautifully written, but does the liquid meet the stated four basic requirements, such as: high boiling point, minimal corrosiveness, lubricating properties and stable viscosity. This can only be learned through experience and user reviews.
Conducted by expertscen website staff, the best foreign-made brake fluids are: Castrol React DOT4(price 450 rub.), Motul DOT 5.1- will cost at least 600 rubles, Liqui Moly Bremsenflussigkeit DOT4– 300 rub. The list of worthy brake fluids from domestic manufacturers includes: Ros DOT-4– 180 rub., Sintec Super DOT-4- 100 rubles.
But in order not to endanger yourself and other participants traffic It is also worth paying attention to those brands whose quality is not at the highest level. Among such dubious TJs are: Luxe DOT-4(“Dolphin Industry”), “ Sintec DOT-4” (TOV “TSKH-Khimreaktiv”) and “ Alaska DOT-4”(Tektro LLC), it is they that do not meet the requirements of the DOT-4 class according to the boiling point. In addition, the Alaska DOT-4 liquid also has a deviation in viscosity at -40°C. In turn, such liquids as: “ Oilright DOT-4”(Tektron LLC) and Lux DOT-4(CJSC “Delfin Industry”) have enough low temperature boiling in a liquid that contains moisture, such parameters do not even correspond to the DOT 3 class. Deviations to the DOT 4 viscosity requirements at -40°C are also observed in liquids: PP “Lumo”(Ukraine) and Belhim DOT 4(“BelKhimGroup”, Belarus), which is 15-25% higher than the norm.
When choosing brake fluid, you can draw analogies for a long time, read reviews, consider the list of characteristics, but at the same time you need to remember that even the brake fluid that has the best performance among others has its own service life and it must be replaced strictly according to stated regulations from the manufacturer, because your safety depends on the condition of your car.
To summarize, let's say that you only need to use the brake fluid that the car manufacturer recommends. When buying brake fluid for your car, be careful pay attention to the specification, which is necessary for the car. If we talk about the required amount for replacing brake fluid, then, as a rule, in domestic cars it is required from 0.5 to 1 liters, while the volume of fluid in the brake system of foreign cars is from 1-1.5 liters. Therefore, when replacing and bleeding brakes, take this fact into account and always monitor its level in expansion tank.
The automobile braking system can be called one of the most important in the operation of a car, because without it more than one vehicle cannot exist. Therefore, for the brakes to function flawlessly, it is necessary that the system elements be reliable. No exception is brake fluid VAZ, in this publication we will figure out what kind of liquid is needed and after what period of time it is needed replacing brake fluid .
Not every car enthusiast knows that the fluid in the brake system needs to be changed from time to time. Some people believe that it is only necessary to periodically top up the brake fluid so that air particles do not appear in the system, which will impair the performance of the brakes. However, this opinion is not entirely correct, although you should not refuse this operation. The fact is that during the operation of the car, moisture forms in the brake system drive, which is safely absorbed by brake fluid. The presence of moisture in a liquid is no less dangerous than the presence of air in it, since work in this case becomes ineffective and is subject to corrosion. Based on this, it is recommended that replacing brake fluid was carried out not only on the manufacturer’s recommendation, but also upon independent detection of moisture and air in it.
How to determine if your brake fluid needs to be replaced
As a rule, the manufacturer, in the list of work performed during scheduled maintenance, determines its brake fluid replacement interval for each vehicle individually. For example, this interval is 45,000 km. mileage or at least after three years of operation. The replacement period may also be affected by the type of brake fluid and the design of the brake system. However, car owners are recommended to carry out visual inspection of the fluid from time to time, and they should pay attention to its color. If you look into brake fluid reservoir, you will see that it has a dirty tint, this indicates that some elements are worn out, therefore, in this case, a complete diagnosis is recommended. If the liquid has a brownish tint, this is a sign that it contains water. In any of the above cases it is necessary replacing brake fluid.
What kind of brake fluid is needed for a VAZ
All brake fluid has its own classification, which indicates its composition and properties. At the moment, there are several brands of TJ - DOT 3, 4, 5 and 5.1. There is also another outdated type of brake fluid BSK, which is still used on older cars.
- DOT 3 It is made on a glycol basis, which includes anti-corrosion and lubricating additives. DOT 3 is recommended for use on low-speed vehicles with front and rear drum brakes. DOT 3 brake fluid reacts poorly to negative temperatures and at -40 degrees its viscosity increases, which negatively affects the operation of the braking system. Therefore, it is extremely undesirable to fill in such liquid on cars operated in northern regions.
- DOT 4 is also made on a glycol basis, but unlike DOT 3 it contains additives that increase the boiling point of the brake fluid, which allows it to be used on high-speed cars, where during braking the slowing mechanisms are exposed to high temperatures.
- DOT 5 It is made on a silicone basis and also has fairly high temperature conditions - 180-260 degrees. With and lower viscosity 900 sq. mm/s. DOT brake fluid 5 is more suitable for cars with powerful vehicles, which, as a rule, are driven quickly and difficultly.
- DOT 5.1 manufactured on a glycol base, but with DOT 5 properties. Increased boiling point, more anti-corrosion additives, and low viscosity - 900 sq. mm/s., used on cars with powerful engines.
- BSK– this type includes those made on the basis of Butyl Alcohol and Castor Oil, hence the abbreviation in the name. It has very low boiling readings of TJ (115-120 degrees C), as well as at – 20 degrees. It crystallizes, which renders the car’s braking system unusable.
Is it possible to mix brake fluids?
Theoretically, brake fluids that contain the same component, for example, DOT 3, DOT 4, DOT 5.1 contain glycol, must be mixed, however, due to the presence of a certain set of additives in them, this can only be done in extreme cases, after which a complete replacement of the brake fluid is mandatory. You cannot use TJ in a brake system that is designed for a certain type, for example a DOT 5 fill, which is made on a silicone basis; in a system for DOT 3, DOT 4, DOT 5.1, rubber drive elements (cuffs, seals) may fail.
Keywords: brake fluid, replacing brake fluid, VAZ brake fluid, brake fluid reservoir, what kind of brake fluid, brake fluid dot, brake fluid dot 4, brake fluid dot
To check the level and top up brake fluid in the brake hydraulic reservoir on a VAZ 2106, you will need:
brake fluid, clean rag.
RECOMMENDATION
Brake fluid type: “Tom” or “Rosa” with a class not lower than DOT-4. When the brake fluid level in the brake reservoir drops below the “MIN” mark, the warning lamp on the instrument panel lights up red. We recommend checking the level before each trip and, if necessary, adding fluid to the brake reservoir without waiting for the warning light to come on: this operation is best done in advance. If you have to add brake fluid to the reservoir quite often, immediately contact a specialist or fix the problem yourself (see “Brake system of a VAZ 2106”). When replacing brake fluid in the system, remember or write down the brand of fluid that was added so that when topping up, use the same brand. When installing a brake reservoir cap with a float, the fluid level in the reservoir increases slightly due to the volume of the float.
On a VAZ 2106 car, the brake reservoir for the hydraulic brake drive is located in the engine compartment in the left rear corner next to the hydraulic clutch reservoir.
WARNING
Take precautions when working with brake fluid: it is toxic. It is unacceptable for brake fluid to come into contact with wires, plastic or painted body parts, so always use clean rags when filling. If brake fluid gets on these parts, wipe them off immediately. Use only brake fluid recommended by the manufacturer. Do not reuse brake fluid that has been drained from the system: it is contaminated, saturated with air and moisture. Only top up the brake reservoir new fluid the brand that was poured before. HELPFUL ADVICE
In order not to expose yourself in the future to unforeseen expenses for repairing the brake system, or even the entire car as a whole, promptly replace the brake fluid on your VAZ 2106 with fresh brake fluid. It is very hygroscopic and absorbs moisture from the air, which, in addition to causing corrosion of brake system parts, increases the boiling point of the fluid itself, which can lead to brake failure during frequent heavy braking.
1. Open the hood of the VAZ 2106 car. Check the fluid level in the brake reservoir. The brake fluid level should be between the “MAX” mark and the lower edge of the brake reservoir filler neck.
2. To add fluid, unscrew the brake reservoir cap and remove it along with the brake fluid level sensor float. Place the lid on a clean cloth, avoiding contamination of the lid and liquid dripping from it.
NOTE
If the brake fluid level sensor wires interfere with removing the cover, disconnect them.
3. Carefully add brake fluid to the reservoir up to the “MAX” mark. When the float cap is installed, the level will rise to normal.
4. Close the lid. Reconnect the wires to the brake fluid level sensor if they were disconnected. The order of connection does not matter.
HELPFUL ADVICE
After adding fluid, as well as at any opportunity, check the serviceability of the brake fluid level sensor located in the reservoir cap.
The VAZ 2107 is far from a perfect car; it cannot boast of the reliability of its systems. Including brake mechanisms, on which the safety of driving depends. Sometimes situations arise when the system does not work efficiently or there is a brake fluid leak - in such cases, immediate repairs are required. You can do the work yourself, for which you will need to prepare necessary tool and read the instructions.
Malfunctions of the brake system of the VAZ 2107
The safety of driving a VAZ 2107, like any other car, directly depends on the effectiveness of the braking system. If problems arise with it or repairs are carried out, the brakes need to be bled. In order for the system to always be in good condition, you need to know how malfunctions manifest themselves and what causes them.
The brake system of the VAZ 2107 consists of the following elements: 1 - brake disc; 2 - brake pedal; 3 - vacuum booster; 4 - main cylinder for hydraulic brakes; 5 - pipeline of the front brake drive circuit; 6 - front brake protective cover; 7 - front brake caliper; 8 - vacuum pipeline; 9 - master cylinder reservoir; 10 - drive lever button parking brake; 11 - parking brake drive lever; 12 - lever latch rod; 13 - lever latch; 14 - brake lever bracket; 15 - return lever; 16 - pipeline of the rear brake drive circuit; 17 - flange of the cable sheath tip; 18 - wheel cylinder of the wheel brake; 19 - rear brake pressure regulator; 20 - pressure regulator drive lever; 21 - brake pads; 22 - lever for manual drive of the pads; 23 - rod of the pressure regulator drive lever; 24 - bracket for fastening the tip of the cable sheath; 25 - rear cable; 26 - lock nut; 27 - adjusting nut; 28 - bushing; 29 - rear cable guides; 30 - guide roller; 31 - front cable; 32 - parking brake warning lamp switch stop; 33 - brake light switch
Soft brake pedal
The normal state of the brake pedal on the “seven” is one in which there are no jerks or dips at the moment it is pressed and there is no need to make any special efforts. However, with use vehicle Drivers may encounter a situation where the brake pedal has a different condition: it may be too soft or too tight. Both phenomena are considered unacceptable and indicate problems with the braking system and the need for prompt repairs. Most often, the pedal becomes soft when the system is filled with air. Sometimes this phenomenon is also called a failure. The malfunction is eliminated by bleeding the brakes, as a result of which air is removed from the system, which could enter it for the following reasons:
Stiff pedal
Excessive force to press the brake pedal is mainly required when the vacuum booster (VS) is faulty. This device creates a vacuum in intake manifold, due to which the necessary braking torque occurs with little effort on the part of the driver.
The vacuum amplifier consists of the following parts: 1 - tip mounting flange; 2 - amplifier housing; 3 - rod; 4 - cover; 5 - piston; 6 - amplifier mounting bolt; 7 - spacer ring; 8 - valve spring support cup; 9 - valve; 10 - valve support cup; 11 - return spring support cup; 12 - protective cap; 13 - protective cap holder; 14 - pusher; 15 - air filter; 16 - valve return spring; 17 - valve spring; 18 - housing cover seal; 19 - retaining ring of the seal; 20 - thrust plate; 21 - buffer; 22 - valve body; 23 - diaphragm; 24 - valve body return spring; 25 - rod seal; 26 - master cylinder mounting bolt; 27 - rod seal cage; 28 - adjusting bolt; 29 - hose tip; 30 - valve; A - vacuum cavity; B - channel connecting the vacuum cavity with the internal cavity of the valve; C - channel connecting the internal cavity of the valve with the atmospheric cavity; E - atmospheric cavity
The reasons that lead to the pedal becoming tight may be the following:
One wheel does not brake
Sometimes situations arise when one of the wheels brakes worse than the others, or there is no braking at all. Reasons may be brake pads or cylinders, it is assumed that the system is bled and there are no leaks. To determine in more detail what caused the problem, you will need to unscrew the wheel and inspect the brake drum and pads. You should then ask someone to press the brake pedal. The force should be small, but sufficient to force the pistons slightly out of the cylinders. If this does not happen, then the unit needs to be replaced. In addition, you need to try to return the pistons back to the cylinders by “pressing” them with a screwdriver. If this cannot be done, the mechanism must also be replaced. The pistons of the front brake cylinders may become sour due to the rupture of the rubber boot, as a result of which they become immobile.
The inspection procedure for rear and front brakes is the same.
Liquid is leaving the reservoir
One of the maintenance points for the VAZ 2107 is monitoring the level of brake fluid in the expansion tank. If it is found that it has decreased, it is imperative to find out the reason that led to this. You should not delay it, as there may be breakdowns in the braking system that can lead to failure when you press the brake pedal in an emergency. Let's look at the most likely reasons why liquid may leave the tank:
As the brake pads wear, the piston stroke increases. brake unit, which can also lead to a decrease in the fluid level in the tank.
In any case, you need to control the level and not allow it to drop below the minimum mark, adding fluid in a timely manner.
Repair of master and working brake cylinders
The main brake cylinder is the main part of the hydraulic brake drive. When the driver presses the brake pedal, the GTZ creates high pressure in the system, which drives the pistons of the braking mechanisms. The latter press the brake pads against the discs and drums.
Repair or replacement of the master cylinder is carried out when the unit does not cope with its functions. To execute renovation work, the mechanism must be removed from the vehicle and disassembled. To do this, you will need a set of keys and screwdrivers, as well as a repair kit for the GTZ and brake fluid. To dismantle the cylinder, you need to remove the hoses and tubes connected to it, and then unscrew the fasteners to the vacuum booster. To disassemble, carefully unscrew the plug nut so that the parts located inside do not fly apart. After disassembly, the worn elements are replaced with parts from the repair kit. Assembly is performed in reverse order.
The brake wheel cylinders are repaired in the same way. If the cuffs or piston are in poor condition, then the parts need to be replaced. It is best to change the entire cylinder, which will be much more reliable.
Video: GTZ repair on a VAZ 2107
Replacing brake hoses
Brake hoses are replaced when leaks are detected that appear as a result of rubber aging. The technical literature says that it is extremely undesirable to use hoses that were installed on a car more than three years ago. This is explained by the fact that rubber not only ages, but is also more subject to deformation.
Brake hoses on the VAZ 2107 are located both in the front and rear of the car. They supply brake fluid to the working cylinders. Having determined that the rubber element needs to be replaced, you need to prepare the following list of tools and materials:
- pliers;
- screwdrivers;
- a set of keys;
- new hose;
- brake fluid.
Replace the brake hose as follows:
During the repair process, washers are replaced with new ones, since they are used as seals, and when installing old parts, there is a possibility of brake fluid leaking.
The rear brake hose is attached in a similar way, the only difference being that the front one is secured to the caliper with a bolt, and the rear one with a nut. To disconnect the hose and tube, you need to use wrenches: one unscrews the tube, the other holds the nut of the flexible element. After the tube has loosened slightly, remove the stopper with pliers. Having completed dismantling the damaged part, install a new one. At the end of the procedure, the reservoir is filled with brake fluid, after which the system is pumped.
Vibrations in the steering wheel and brake pedal
Although rare, there are still situations when, when you press the brake pedal, vibration is felt, not only in the pedal, but also in the steering wheel. The reason for this is the twisted brake disk. Damage may occur during aggressive driving, when you need to brake frequently and sharply. At the same time, the disks heat up, and if water gets on them at this moment, a temperature difference occurs, which contributes to the destruction of the disk. Due to such damage, loss of vehicle control and other unpleasant consequences may occur. If this malfunction occurs, you must visit a service station, where the damaged brake disc is subjected to grooving.
What kind of brake fluid should I fill in the VAZ 2107 and how much?
The hydraulic brake system of the VAZ 2107 uses DOT-4 brake fluid. Its volume is 0.382 l. The fluid is topped up or changed not only in case of repairs, but also when the color changes or moisture gets into it. As a rule, on classic Zhiguli cars complete replacement fluids are performed every 3 years. The essence of the procedure is to pump fluid through the system.
Procedure for bleeding the brakes
To bleed the brakes on the “seven”, as a rule, 2 people are required: one is under the car and works directly with the brake cylinders, and the second is located inside the car and presses the brake pedal. The following tools are required for work:
- socket wrench 8/10;
- 8/10 open-end wrench or special for brake pipes;
- hose of appropriate diameter;
- container for waste liquid.
Bleeding begins from the furthest wheel from the GTZ, so it is performed in the following sequence:
For bleeding brake mechanisms rear wheels you need to go under the car. Work on the front brakes is carried out after preliminary dismantling of the wheels. Otherwise the process is the same:
- Remove the protective cap from the fitting of the working brake cylinder.
- Place an 8/10 socket wrench on the fitting and slightly loosen the tightening.
- A hose is connected to the fitting, the other end of which is lowered into the container.
- Press the brake pedal until it becomes hard and hold it down.
- Unscrew the fitting half a turn, while the brake fluid begins to flow out through the hose, and the pedal rests on the floor. Do not release the pedal until the fluid stops flowing.
- Tighten the fitting and repeat the procedure until liquid begins to flow through the tube without air bubbles.
- The procedure is repeated with other wheels of the car.
- At the end of pumping, the fitting is closed with a rubber cap.
During pumping, you need to control the liquid level in the expansion tank so that air does not enter the system.
Video: pumping brakes on a VAZ
Why don't the brakes bleed?
One of the problems that many VAZ 2107 owners face is the inability to bleed the brakes after repairing or replacing the master cylinder. It would seem that a new or repaired part has been installed, bleeding is carried out correctly, but the result is zero. The essence of the problem is that in most cases, when installing a GTZ, tubes and hoses are first connected to it, then brake fluid is poured into the reservoir, and only after that they begin bleeding. However, there is air in the cylinder itself, so you need to bleed it first, and then start working on the brakes.
The fact that there is air in the GTZ is also indicated by the brake pedal, which lies on the floor.
To deal with the problem, you do not need to tighten the fittings on the tubes - just tighten them. After this, pour brake fluid into the reservoir and release the fittings a few turns so that fluid and air flow out of them. Alternatively, to speed up the process, you can wipe the neck of the tank and blow into it to create pressure. After the fluid flows without air, the fittings are clamped and the standard procedure for bleeding the brakes begins.
In addition, a pumping problem can occur when installing a defective cylinder or when a part is incorrectly repaired. If a problematic product is encountered, the fluid is bypassed, which simply flows from the tank to the cylinder and back, i.e. it does not pass further than the GTZ. In this case, the part must be replaced. If the cylinder has been repaired, the procedure will need to be repeated, since, most likely, an error was made during assembly.
In order for the “Seven” brake system to work properly, it is necessary to periodically inspect its elements, monitor the level of brake fluid in the expansion tank, and if it decreases, identify the reason that led to this. Since many problems with the hydraulic brake system require bleeding, you need to know what should be done and in what order - there is nothing complicated in this process.