DIY abs pump repair

In detail: do-it-yourself abs pump repair from a real master for the site my.housecope.com.

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Good day, dear motorists! Among us, most likely, there is no driver who at least once did not experience a feeling of helplessness at the moment of braking. When the car continues to move, and not at all in the direction that the driver wants. Skid.

Fortunately, engineering thought does not stand still. The modern driver is armed with a system like ABS. Let's take a closer look at the system, and see if it is possible to pump the brakes with ABS with our own hands.

ABS (Anti-lock Braking System) is an anti-lock braking system that prevents the wheels from locking during emergency braking.

The main task of the ABS is to: adjust the speed of rotation of all wheels. This is done by changing the pressure in the vehicle's braking system. The process takes place using signals (pulses) from each wheel sensor, which are sent to the ABS control unit.

How the anti-lock braking system works
The contact patch of the car wheels is in relative immobility to the roadway. In physics, the wheels are affected by the so-called. static friction force.

Taking into account the fact that the static friction force is greater than the sliding friction force, the ABS effectively slows down the rotation of the wheels at a speed that corresponds to the speed of the car at the moment of braking.

Video (click to play).

At the moment of the beginning of braking, the anti-lock braking system begins to constantly and accurately determine the speed of rotation of each wheel, and synchronizes it.

Anti-lock braking system device
Here are the main components of ABS:

sensors installed on the car wheel hubs: speed, acceleration or deceleration;
control valves installed in the line of the main brake system. They are also the components of the pressure modulator;
ABS electronic control unit. Its task is to receive a signal from sensors and control the operation of valves.

Bleeding an ABS braking system will require you to have certain technical skills. In addition, it will not be superfluous to study the manual for the construction and maintenance of the brake system of your car.

Features of bleeding brakes with ABS

in cars that have in one unit: a block of hydraulic valves, a hydraulic accumulator and a pump, the replacement of brake fluid and bleeding of the brake system with an anti-lock system is carried out in the same way as bleeding the brakes on a car without ABS, you need to turn off the system by removing the fuse. Bleeding of the circuits is carried out with the brake pedal depressed, the bleed nipple of the RTC must be unscrewed. The ignition is switched on and the pump expels air from the circuit. The bleed nipple is screwed on and the brake pedal is released. An extinguished malfunction lamp is evidence of the correctness of your actions.
Bleeding of the brake system with ABS, in which the hydraulic module with valves and the hydraulic accumulator are separated into separate units, is carried out using a diagnostic scanner to read information from the ABS computer. It is unlikely that you have it. Therefore, bleeding brakes with ABS of this type, most likely, should be done by you at a service station.
Bleeding the brake system with ABS and with electronic activation systems (ESP or SBC) is carried out only under service conditions.

It is important! It should be remembered that the pressure in the brake system reaches 180 atm.Therefore, in order to prevent the release of brake fluid, before disconnecting the brake lines for any system with ABS, it is necessary to discharge the pressure accumulator. To do this, with the ignition off, press the brake pedal 20 times.

ABS brake bleeding technology

Bleeding brakes with ABS, like bleeding a conventional brake system, is performed with an assistant. Turn off the ignition (position "0"). Disconnect the connectors on the brake fluid reservoir.

put the hose on the bleed nipple;
open the union for a turn;
the brake pedal is pressed all the way down and held in the depressed position;
we observe the release of the "airborne" mixture;
we twist the union and release the pedal.

Rear right wheel brake:

put the hose on the bleed nipple, unscrew it one turn;
press the brake pedal all the way, turn the ignition key to position "2". In this case, the brake pedal is held in the depressed position;
a running pump will expel air from the system. That is, as soon as the brake fluid begins to come out without air bubbles, close the union and release the brake.

Rear left wheel brake

the hose is put on the fitting and unscrewed by 1 turn;
DO NOT press the brake pedal;
a running pump pushes out the "airborne" mixture;
press the brake pedal halfway and tighten the union;
release the pedal and wait for the pump to stop completely.

In the reverse order: the ignition key to "0", connect the connectors to the brake fluid reservoir, check the tightness of the brake system (see the ABS malfunction indicator).

Good luck with bleeding the ABS brakes.

Modern anti-lock braking systems (ABS) have long ceased to be a sign of an elite car - they are installed on most new cars coming off the assembly line. While this useful piece of equipment is quite reliable, it still has a number of problem points that can affect smooth operation. The most vulnerable elements of the ABS are the wheel speed sensors located on the vehicle's hubs.

The ABS sensor is an inductor paired with a toothed disc, which is also mounted on the hub. Together they measure the speed at which the wheel is spinning. The first symptom of a device malfunction will be the signal of the warning lamp located on the dashboard of the car.

When the system is stable, the controller goes out a few seconds after the engine is started. If the indicator stays on or starts blinking chaotically when the car is moving, anti-lock brakes require immediate intervention.

Along with the signal of the indicator lamp, a sensor malfunction is indicated by:

alphanumeric error code of the on-board computer;
lack of characteristic sound and vibration when pressing the brake pedal;
permanent blocking of wheels during emergency braking;
parking brake controller light signal when the equipment is off.

The appearance of any of these symptoms requires a complete system diagnosis. Note that the help of car service technicians in solving this issue is completely optional. There are various ways to test an ABS sensor, and in most cases it is easy to do the job yourself.

As a result of device diagnostics, it is possible to determine in which sensor assembly there is damage. If the tester readings tend to zero, this indicates a short circuit in the connection wires, "infinity" signals a violation of the integrity of the coil winding. There is an opinion that the repair of the wiring does not cause any problems, but the faulty sensor is easier to simply replace. It is difficult to disagree with the first thought, but the next "point" can be disputed.

The fact is that the cost of some sensors reaches 14-18 thousand rubles, and you will have to wait for their delivery for a long time.Having certain skills, a stock of patience and natural ingenuity, it will be much more useful and faster to repair the device than to pay for a long-awaited expensive order. Note that this advice is only advisory in nature - the final verdict is yours. If the decision to repair is still made, we will be happy to help you to carry it out correctly.

After diagnostics and detection of a faulty element, the device must be dismantled for further repair. The process of removing it is similar to the first stage of measures to replace the ABS sensor and is not particularly difficult.

Attention! Elements can stick to the seat; it takes a lot of patience to remove them from the slot. Professional technicians advise to moisten the metal around the device abundantly with WD-40 liquid and carefully remove the sensor, slowly loosening it.

Having finished dismantling the device, we proceed to the repair work:

The repair of the sensor is completed, you can mount it on the hub by grinding the new body with sandpaper for a better fit to the seat. When installing a repaired device, be sure to observe the following conditions:

Place the sensor core parallel to the teeth of the counter disk, making sure that it does not overlap two adjacent teeth.
We leave a gap between the tine and the core of 0.9–1.1 mm.

The final stage in the repair of any of the ABS elements is to check the system operability. We carry it out by starting the car engine and making sure that the controller on the dashboard goes out 3-5 seconds after the start.

Attention! If the ABS indicator lamp periodically lights up when the car is moving after repairing the sensor, change the phasing of its connection wires.

Note that some sensors produced by the foreign auto industry can be disassembled without a fundamental violation of the integrity of the structure - the upper shell of the part can be removed by pre-heating with a construction hairdryer or blowtorch. An example of repairing such a device is shown in the video.

There shouldn't be any special problems with the issue of replacing or restoring the sensor wiring. For these purposes, any two-core cable of a similar cross-section or two pieces of field wire of the required length will do. In work, it is necessary to use only the soldering method and carefully insulate the joints with heat shrink tubes or electrical tape. Special attention should be paid to the sealing rubber bands, which are located at the points of attachment of the wiring to the body parts - when completely replacing the cord, they should be located in the same place. Image - DIY abs pump repair

When replacing the wire, we install sealing rubber bands at the points of its attachment to the body

Attention! When connecting the wiring to the ABS sensor, take into account that the device has polarity. In the vehicle operating instructions, the color coding of the wires is indicated - on the connector of the part there are exactly the same designations.

In more detail, the process of repairing the ABS sensor wiring is described in the video presented.

Repairing an ABS sensor is a very time-consuming and troublesome task. If you are not distinguished by perseverance and patience, or simply do not have free time, you probably should not get down to business. Well, those who are accustomed to solving all problems on their own and do not want to spend extra money will now easily do this work on their own.Like any other system in a car, the ABS periodically requires maintenance, preventive maintenance and repair. Of course, all the electronic units of this useful system are well protected from external influences and rarely fail, but every motorist should be prepared for the fact that sooner or later they will have to roll up their sleeves and start preventive or repair work. Periodic self-diagnosis is not canceled even by the presence of a self-test system in each car.It is necessary to pay attention to the prevention of ABS, since it performs a very important function in the car - it prevents the complete blocking of the wheels during braking. This, in turn, not only reduces the braking distance, but also allows the driver to maneuver during braking - without ABS, with locked wheels, any steering movement will lead to an uncontrollable skid of the vehicle, the consequences of which can turn into a disaster.It is quite natural that do-it-yourself ABS repair is possible only if the problem is accurately identified. Any car with an anti-lock braking system also has a self-test mechanism that is activated when the ignition is turned on. If the system is faulty, an error code is displayed on the on-board computer. Having looked at the instruction manual, the driver will easily understand the current problem and appreciate the possibility of self-repair.The entire anti-lock braking system can be conditionally divided into a central part, which includes electronic and hydraulic units, and a peripheral part, which includes wheel sensors. It is they who most often become the culprits of failures in the operation of the ABS. The second most popular cause of problems is worn wiring and poor connections that are unable to ensure the integrity of the electrical circuit.The main part of the ABS is the electronics and the hydraulic unit. They fail quite rarely, and their self-repair is highly undesirable without the appropriate equipment and qualifications. If the reason for the interruptions in the wiring, terminals or the sensors themselves, which are installed on each hub, it is quite possible to do without a visit to the car service.If it is almost impossible to repair the ABS unit with your own hands, then the wires and sensors are completely at the mercy of the driver. If the ABS indicator lights up frequently while driving, the first step is to check all the wires leading from the unit to the sensors. They should not have strong creases, damage to the insulation. If there are bare areas, such wiring must be urgently replaced - it is better to spend a little time on this than to find yourself in a critical situation without the help of the ABS.

The next step in self-troubleshooting of the ABS will be checking the sensors. To accurately determine their performance, you will need a multimeter with which the resistance on each of them is checked. The normal values of this indicator can be clarified in the car operating manual - for each system it can differ significantly. To check, you need to either lift the car with a lift, or alternately jack up each wheel.Each sensor is a fairly simple induction coil, so there is no difficulty in understanding whether it is functional or not - if the resistance does not correspond to the standard, the sensor must be definitely replaced. The cost of a new one is not high, the sensor cannot be called a deficit either, and the procedure for self-replacement is not difficult even for a novice car owner.Normally, after turning the ignition key, the ABS indicator on the dashboard should light up, and after 3 seconds go out - this indicates a successful self-test and no problems. If it continues to burn, or lights up while the car is moving, it is advisable to perform the following actions:

park and turn off the engine;

try to start the engine again after 3-5 minutes;

check the voltage at the output of the battery with a multimeter - its minimum value should be 10.5 V;

check the quality of the contact of the power wires, as well as the wires leading directly to the ABS sensors on the wheels.

To do the above, it will take no more than 5-7 minutes.If, after a cursory check of violations, it is not possible to identify the violations, you will have to seek help from professionals, or do it yourself, having devoted a lot of time to checking each sensor.As practice shows, more than 80% of ABS malfunctions are associated precisely with sensors located on the wheels. They have to work in very unfavorable conditions, therefore, periodic problems that arise in their work are more likely a pattern. When starting to repair ABS with your own hands, you can go in two ways - just replace the sensors with new ones or restore the old one to work. In the latter case, you will have to rewind the coil located inside the sensor - this is a difficult and painstaking job, and without skills, a positive result is not guaranteed.It is much easier and more reliable to replace the sensor. To do this, you need to remove the old one, which is attached to the hub with one bolt. To get to the attachment point, you will need to dismantle the wheel, remove the caliper and brake disc. To make it easier for yourself to remove the sensor, you can pre-treat the mounting area with WD-40. Install a new one in reverse order. Repairing the anti-lock braking system, in addition to replacing the sensor, should also include checking the wires; if damaged, they should also be replaced. Otherwise, even a new sensor will not be able to ensure the smooth functioning of the system, and the slightest short circuit will lead to its immediate shutdown. How to properly repair the sensor is shown in the video:

I will say right away that this topic has already been raised here.
I will try to add some photos and some comments on the problems I encountered.
If, when the abs and esp icons light up, and when the block is polled, an error (s) is issued:

Address 03
Controller: 7L0 907 379 G
Component: ESP ALLRAD MK25 0203
Code: 0006146
Service no .: WSC 31414

2 Faults Found:
01276 - Hydraulic pump ABS-V64
012 - Electrical Error in the Circuit - Sporadic
01276 - Hydraulic pump ABS-V64
008 - Plausible Signal - Sporadic

The problem can be eliminated by replacing the motor brushes, or by replacing a seized bearing.

Algorithm:
1. Take off the leashes of the wipers. Unscrew the nuts with a 16-inch head and remove the leashes using a puller. Since it is difficult to find a special puller for wipers, it is possible to remove the leashes with a two-blade puller or a generator bearing puller modified by a grinder.

2. Remove the cover under the windshield (frill). It is necessary to turn the plastic clips 90 g and remove the cover with a little effort.

3. Remove the terminal from the ‘-’ battery.

4. Disconnect the ECU connectors. There are protrusions on the left and right of the connector, so you need to pull for them. The connector will slide off by itself. Remove the engine control unit itself. It is necessary to slightly bend the plastic clips on the sides of the block (in frost or cold weather they tend to break), and then pull the block forward.
Perhaps the engine control unit is riveted to the platform, the connector is covered with a metal plate of the platform, it is impossible to disconnect the wiring harness from the block without riveting. It is necessary to remove the block together with the platform. The platform is attached in three places - with two nuts (you can see them) and one bolt in the depth from the side of the wiring harness. After unscrewing the nuts-bolt, move the block into the engine compartment.

7. Disconnect the connector from the ABS unit.

8. Then unscrew the brake pipes from the ABS unit and slide the prepared tubes over them. The cap of the expansion tank of the brake system does not need to be unscrewed. Seal the holes for the tubes on the removed block with tape to prevent dirt from entering. Keep the removed unit upright to prevent liquid from spilling out.

9. Then unscrew the 3 screws that secure the ABS unit and remove it

10. On the removed unit, unscrew the two screws (torx) and remove the motor cover of the ABS unit. Magnets are installed inside, and therefore the cover is removed with force.It is better to disassemble the motor, as it were, by twisting the metal casing from the plastic cover, spilling the silicone seal with a WD shroud.

You will see brushes inside. If they are intact and not worn out, then grease them with silicone grease (it is better not to use WD) and work out a little. If worn out, then you can pick up domestic counterparts.

Personal experience:
The rear bearing was removed without any problems, but the rotor was displaced only by 1.5 cm along the shaft, in principle enough for the minimum necessary access to the brushes. I took the brushes from a drill, any will do, graphite is very easy to mold with a file. I soldered new brushes to the cut wires from the old ones. For the convenience of work, he clamped the shaft in a small vice and fixed the plastic cover.

Reassemble in reverse order. If a lot of brake fluid has come out of the block / pipes, then it is advisable to bleed the brakes, brake fluid code VAG B 000 750 M3.

After the replacement, the errors disappeared after a 50m ride.

The specified operation was carried out on two machines once with the restoration of the motor, the second just replacing the block. The first time it took about three hours, the second a little over an hour.

Attention: There are two types of ABS motors. On some, the motor cover is not screwed on, but riveted. Make sure in advance that you have it screwed. In order not to disassemble the brake system in vain. Some also repair riveted motors.

Lyrical indentation. Before starting the repair, I searched the Internet in search of information - there are a number of companies in the gold-domed company that are ready to repair the unit (namely the entire ABS ESP unit) for a modest amount of 8500 re. + Remove-put 1500 re.

The algorithm for repairing this error is applicable to most ESP units of VAG cars.

PS Thanks to the person with the nickname omeganet for primary information on repair.

The problem can be eliminated by replacing the motor brushes, or by replacing a seized bearing.

2. Remove the cover under the windshield (frill). It is necessary to turn the plastic clips 90 g and remove the cover with a little effort.

3. Remove the terminal from the ‘-’ battery.

7. Disconnect the connector from the ABS unit.

9. Then unscrew the 3 screws that secure the ABS unit and remove it

Reassemble in reverse order. If a lot of brake fluid has come out of the block / pipes, then it is advisable to bleed the brakes, brake fluid code VAG B 000 750 M3.

After the replacement, the errors disappeared after a 50m ride.

The algorithm for repairing this error is applicable to most ESP units of VAG cars.

PS Thanks to the person with the nickname omeganet for primary information on repair.

Cars change, friends and the forum remain. [my.housecope.com/wp-content/uploads/ext/1209]

Message Anisimov Fedor "21 Jan 2009, 15:23

Anyone who has ever seen the price of a new ABS unit will understand what I mean.

(about 3000 euros)
Before buying a new one, you can try to revive the old one.

I disassembled and assembled mine, replacing the pump brushes.

The problem of finding a 5-spoke torx wrench ended with drilling out the head of the bolts and replacing them with the usual 5X70 hexagon.
Control block. It must be removed before any actions with the pump, because inside the plastic kiramic board. A couple of screws usually come off during disassembly, it doesn't matter the sealant will help.
Next, I recommend riveting the contact from the side of the control unit (where the connector is).
Now remove the motor cover.
If we put everything back together, and take the control unit in our hands, we open the cover VERY CAREFULLY with a bulgak with a thin circle. the gap to the board is about 1mm and we call the mustache going from the board to the connector
Restoration of appearance with black poxypol

In the instructions, we will repair the unit of the brand - Bosch. This is not the best of abesoks, and in addition, this is exactly what is installed on most brands.

for instance in Audi, Volkswagen, Ford, Skoda, Seat, Renault and even Mercedes come across.

Location of the ABS unit under the hood of the Audi A4

The problem starts with a pesky error and a full screen exclamation mark. Because of which nothing else can be shown by the tidy, it cannot until it fixes the problem.

Everything would be fine and it seems possible to drive, but when selling, the buyer often asks a lot of questions seeing this disgrace. And the most calm when on the electrics - everything is in order.

More often, a breakdown occurs in the electronic part of the unit.

The contacts there are thin and fragile. If the problem is similar to the one described below, with sufficient experience with a soldering iron, you will succeed.

We disassemble.
First, let's remove the electronic part. It is connected to the hydraulic (main) part by six bolts. Disconnect the supply cable, then crawl up and unscrew it with a convenient key.

12 contacts of the electro-module

Now you need to carefully open the plastic case of the module.We cut with a cutter along the seam, very carefully, without driving the knife deeply. You can touch the contacts inside.

The case has been opened.
We carefully examine the board under a magnifying glass and a bright lamp. Inspection of this unit revealed damage to two contacts on the left side going to the connector.

From the outside, everything seems normal.

By slightly moving these wires, they easily moved away from the contacts.

Gently solder the wiring into place. You can also solder a new common wire instead of these two. You need to solder very carefully - do not overheat the entire module with the board.

If in the soldering experience they are not strong - it is better to give it to an experienced friend or workshop.

We glue the case back - with good glue (not super).

We return the module to its place.

This instruction was used by: 11006 once.

Most modern cars are equipped with a set of systems aimed at driving safety. To prevent wheel blocking during heavy braking or on a slippery road, the anti-lock braking system ABS (ABS) is used. Fully locked wheels are known to increase the stopping distance of a car, and if only a few wheels are locked, the car is more likely to skid.

The ABS includes several systems - the anti-lock braking system itself, the stability control system and emergency braking. The whole complex is controlled by an electronic control unit, and the final device is the hydraulic system of the vehicle.

Signals for the operation of the ABS systems come from a sensor installed on each of the wheels and monitoring the rotation of the wheel at each moment of movement. Based on the speed of the vehicle, the speed of rotation of the wheel, the condition of the road surface or the angle of inclination of the road, signals for the control valves of hydraulic systems are generated at the output of the electronic unit.

The ABS system is very important for the safe driving of a car, therefore, before undertaking repairs with your own hands, you need to carefully weigh everything. Diagnostics and repair of blocks of the ABS system in a car service, even if it will cost a little more than with your own hands, will give a guarantee that failures will not occur at the most inopportune time.

This is especially true for those who are accustomed to using the ABS and rely on its performance.

Like most electronic systems, the ABS has primary self-diagnostics that operate when the key is turned. Diagnostics usually takes a few seconds. If after this time no system malfunctions are noticed, the alarm on the dashboard will go out. When the car is moving, the ABS diagnostics works continuously, and when the parameters of the sensors or terminal devices are not included in the tolerance zone, a malfunction alarm is triggered. When signaling a malfunction, it is necessary with special care to find a convenient place to inspect the car or get to the nearest car service, especially in cold weather, when the roads are slippery. Sometimes it happens that a malfunction can be eliminated with your own hands in a couple of tens of minutes.

To repair blocks of the ABS system with your own hands, you must first measure the voltage of the battery. If the voltage is less than 10.5 V, the ABS control unit will not turn on, so that there are no errors in operation. At normal voltage, you will have to continue troubleshooting. Most of them are due to the wiring of the sensors. Moisture, getting into the connectors, causes oxidation of the contacts, therefore, first of all, you need to assess the condition of the contacts of each sensor of the ABS systems.

Very often, breakdowns of ABS systems are caused by a malfunction of the control unit sensors. To operate the ABS sensor, a gear wheel is attached to the hubs, and the sensor itself is an inductor located at a distance of 0.2–1.5 mm from the teeth. If all the teeth are in place, then it is necessary to measure the gaps between them and the sensors, if necessary, readjust the mounting of the sensors.Dirt accumulated on the teeth and surfaces of the sensors can adversely affect the operation of the ABS.

The coils themselves are checked with an ohmmeter. The device should show a resistance of 1-3 kOhm, depending on the type of sensor. The main thing is that they are all the same on one car. If the ABS sensor coil shows an open or short circuit or is very different from the rest, then it needs to be replaced or repaired. One can only advise to check the place of entry of the connecting conductors into the device. Perhaps the wires are broken, and, having removed a little insulation from the sensor, you can try to solder the break or short. Many devices can be disassembled by heating them with an assembly hair dryer and removing the plastic cover at the wire entry point. It is under this cover that breaks occur most often. In this case, do-it-yourself ABS repairs will not be very serious. Considering the cost of the sensor, such a technique may have a right to exist.

If the sensors are in order, the state of the wiring from them to the electronic unit is not satisfactory, then you need to inspect the control unit. DIY repair of ABS control units is advisable only for those who are very well versed in electronics, know how to use a soldering iron and have the skills to repair electronic devices.The ABS control unit, as a rule, is made non-separable and hermetically sealed with glue. The printed circuit board on it is filled with a special sealant. If you carefully open it, you can look at the wires soldered to the printed circuit board of the block. Very often they do not withstand vibration and come off. The broken wire must be carefully evaporated and another must be soldered instead. For soldering, you need to use an electric soldering iron with a power of no more than 40 watts. Rosin or its solution in ethyl alcohol is used as a flux.Do not use soldering acid for ferrous metal soldering as it will corrode printed tracks and copper wires over time.To check the coils of the hydraulic valves, you need to free their leads from the sealant and apply a voltage of 12 V. A normal coil should work like an electromagnet, attracting steel objects to itself.

Coil rewinding and PCB repair should only be performed by a specialist. It is very difficult to do this with your own hands and, moreover, without any guarantee. In any case, after the repair has been completed, the sealant layer must be restored. You can use neutral silicone for this. Regular silicone contains acetic acid. It cannot be used categorically.Some time after the repair, the printed conductors on the control unit board will be completely corroded. For the most part, replacement of the control unit is required.One more note. When replacing brake fluid in a car, it must also be drained from the accumulator (pressure accumulator) of the ABS. This can be done by pressing the brake pedal several times with the ignition off. With the ignition on, the pump in the hydraulic block will try to make up for the loss of fluid. To avoid damage to the electronics, during welding on a car, the ABS control unit must also be disconnected from the power circuits by pulling out the connector. Image - DIY abs pump repair

ABS (Anti-lock Braking System) is an anti-lock braking system that prevents the wheels from locking during emergency braking.

The main task of the ABS is to: adjust the speed of rotation of all wheels.This is done by changing the pressure in the vehicle's braking system. The process takes place using signals (pulses) from each wheel sensor, which are sent to the ABS control unit.

How the anti-lock braking system works
The contact patch of the car wheels is in relative immobility to the roadway. In physics, the wheels are affected by the so-called. static friction force.

At the moment of the beginning of braking, the anti-lock braking system begins to constantly and accurately determine the speed of rotation of each wheel, and synchronizes it.

Anti-lock braking system device
Here are the main components of ABS:

sensors installed on the car wheel hubs: speed, acceleration or deceleration;
control valves installed in the line of the main brake system. They are also the components of the pressure modulator;
ABS electronic control unit. Its task is to receive a signal from sensors and control the operation of valves.

Features of bleeding brakes with ABS

in cars that have in one unit: a block of hydraulic valves, a hydraulic accumulator and a pump, the replacement of brake fluid and bleeding of the brake system with an anti-lock system is carried out in the same way as bleeding the brakes on a car without ABS, you need to turn off the system by removing the fuse. Bleeding of the circuits is carried out with the brake pedal depressed, the bleed nipple of the RTC must be unscrewed. The ignition is switched on and the pump expels air from the circuit. The bleed nipple is screwed on and the brake pedal is released. An extinguished malfunction lamp is evidence of the correctness of your actions.
Bleeding of the brake system with ABS, in which the hydraulic module with valves and the hydraulic accumulator are separated into separate units, is carried out using a diagnostic scanner to read information from the ABS computer. It is unlikely that you have it. Therefore, bleeding brakes with ABS of this type, most likely, should be done by you at a service station.
Bleeding the brake system with ABS and with electronic activation systems (ESP or SBC) is carried out only under service conditions.

It is important! It should be remembered that the pressure in the brake system reaches 180 atm. Therefore, in order to prevent the release of brake fluid, before disconnecting the brake lines for any system with ABS, it is necessary to discharge the pressure accumulator. To do this, with the ignition off, press the brake pedal 20 times.

ABS brake bleeding technology

Bleeding brakes with ABS, like bleeding a conventional brake system, is performed with an assistant. Turn off the ignition (position "0"). Disconnect the connectors on the brake fluid reservoir.

put the hose on the bleed nipple;
open the union for a turn;
the brake pedal is pressed all the way down and held in the depressed position;
we observe the release of the "airborne" mixture;
we twist the union and release the pedal.

Rear right wheel brake:

put the hose on the bleed nipple, unscrew it one turn;
press the brake pedal all the way, turn the ignition key to position "2". In this case, the brake pedal is held in the depressed position;
a running pump will expel air from the system. That is, as soon as the brake fluid begins to come out without air bubbles, close the union and release the brake.

Rear left wheel brake

the hose is put on the fitting and unscrewed by 1 turn;
DO NOT press the brake pedal;
a running pump pushes out the "airborne" mixture;
press the brake pedal halfway and tighten the union;
release the pedal and wait for the pump to stop completely.

In the reverse order: the ignition key to "0", connect the connectors to the brake fluid reservoir, check the tightness of the brake system (see the ABS malfunction indicator).

Good luck with bleeding the ABS brakes.

Video (click to play).

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