Trouble-free quality work brake system- is a pledge safe driving and ensuring that, if the driver reacts, he can stop the vehicle and avoid or minimize the consequences of an accident. From time to time it is necessary to check the brake system for reliable operation, especially if the car is constantly operated in a city where the driver practically does not move on high speeds and does not resort to emergency braking. It is also necessary to check the brake system when buying a car "from hand", and in this article we will look at how to do this.
Checking the components of the brake system
To stop the car, the driver just needs to press the brake pedal or emergency cases pull the handbrake. These two actions only seem simple, but for their competent execution, dozens of details must work together. Not all elements that act when braking the car can be reached without removing the units, but this is not necessary if there are no problems with stopping the car while driving. To check the brake system for critical problems, just do the following:
The brake system of the car also applies hand brake and its condition must be monitored. A serviceable handbrake should prevent the car from rolling back on a slope of 23%. In addition, you need to count the number of clicks that take place when the handbrake is raised to fix the car. Ideally, the handbrake is tightened in 3-4 clicks. In a situation where the handbrake does not hold, you need to tighten it, and also check the condition of the handbrake pads.
Checking the brake system on the move
Apart from visual inspection elements of the brake system and their diagnostics, you can test the operation of the brakes in motion.
Important: Checking the brake system in motion can only be performed after you have made sure that there are no obvious problems with its components.
To test the brake system in motion, you need to accelerate the car to a speed of 40-50 kilometers per hour on a free stretch of road, then sharply press the brake pedal and follow the process of braking the car. If the braking system steering work perfectly, and there are no problems with the tires, the car should not “blow down” to one side during deceleration. The length of the braking distance on each car is individual, and it depends on the weight of the car, the condition of the roadway, the quality of the tires and many other factors.
We recommend reading:
Note: If the vehicle is equipped ABS system, the process of its braking will be slightly different. By pressing the pedal sharply, the driver will feel that there is a reverse kickback in the form of a kind of vibration. When the vehicle also has a system exchange rate stability, at hard braking an indicator on the instrument panel will light up from time to time, signaling its operation.
A well-functioning braking system is essential to safe driving and ensures that if the driver reacts, he or she can stop the vehicle and avoid or minimize the consequences of an accident. From time to time it is necessary to check the brake system for reliable operation, especially if the car is constantly operated in a city where the driver practically does not move at high speeds and does not resort to emergency braking. It is also necessary to check the brake system when buying a car "from hand", and in this article we will look at how to do this.
How to check the health of the brake system yourself
To stop the car, the driver just needs to press the brake pedal or, in emergency cases, pull the handbrake. These two actions only seem simple, but for their competent execution, dozens of details must work together. Not all elements that act when braking the car can be reached without removing the units, but this is not necessary if there are no problems with stopping the car while driving. To check the brake system for critical problems, just do the following:
- Make sure the ABS is working if the vehicle is equipped with the system. A number of diagnostic bulbs are displayed on the instrument panel, among which there is an indicator that indicates the presence or absence of malfunctions of the anti-lock braking system. If when starting the engine ABS bulb lights up and quickly goes out, this indicates that the computer has checked and found no errors in the system. In a situation where the light does not light up at all or is constantly on, you need to check anti-lock braking system and an indicator for problems;
- Check vacuum booster and brake hoses. It should be noted that the old Russian cars the vacuum amplifier is most often absent;
- Test the tightness of the brakes. To do this, get into the car and press the brake pedal several times. It should not "fall through", and the driver will feel resistance when pressed. After several clicks in a row, the pedal should become even tighter. If this did not happen, and the resistance remained at the same level or the pedal became “softer”, this indicates a violation of the tightness of the brake system;
- Check level and quality brake fluid. To do this, open the hood, find the brake fluid reservoir and make sure that it is filled with it no higher than the maximum mark and not lower than the minimum. It is also important that the liquid does not smell like burning.
Please note: If there is a depressurization of the brake system, the brake fluid will flow out of the reservoir, which is hard not to notice; - Inspect pads and discs. Make sure there is no wear brake pads. Most pads have wear indicators that can be used to draw appropriate conclusions. If there are no such indicators, you can follow the rule that the thickness friction lining should be at least 1-1.5 mm. It is also important to check the brake discs for wear.
The brake system of the car also includes a hand brake, and its condition must be monitored. A serviceable handbrake should prevent the car from rolling back on a slope of 23%. In addition, you need to count the number of clicks that take place when the handbrake is raised to fix the car. Ideally, the handbrake is tightened in 3-4 clicks. In a situation where the handbrake does not hold, you need to tighten it, and also check the condition of the handbrake pads.
CHECKING THE BRAKING SYSTEM IN MOTION
In addition to visual inspection of the elements of the brake system and their diagnostics, you can test the operation of the brakes in motion.
Important: Checking the brake system in motion can only be performed after you have made sure that there are no obvious problems with its components.
To test the brake system in motion, you need to accelerate the car to a speed of 40-50 kilometers per hour on a free stretch of road, then sharply press the brake pedal and follow the process of braking the car. If the braking system and steering work perfectly, and there are no problems with the tires, the car should not “drag” to one side during deceleration. The length of the braking distance on each car is individual, and it depends on the weight of the car, the condition of the roadway, the quality of the tires and many other factors.
Please note: If the vehicle is equipped with ABS, the braking process will be slightly different. By pressing the pedal sharply, the driver will feel that there is a reverse kickback in the form of a kind of vibration. When the vehicle also has a stability control system on board, an indicator on the instrument panel will occasionally light up during heavy braking to indicate its operation.
It should be noted that the brake system of most modern cars can also be checked using a diagnostic stand, which will indicate the presence of malfunctions, if any.
Brake fluid - overriding element brake system of the car, with its help the force is transmitted from the brake cylinder to the wheel cylinders, therefore, in fact, it ensures the safety of the driver and passengers, and it is extremely important to monitor its level.
When is it necessary to check the brake fluid level?
Ideally, the fluid level should be checked every time before driving.
Not all drivers are so scrupulous, but there are a number of cases when it is simply necessary to take a few minutes to make sure that the trip is safe:
- The brake pedal became "hard";
- Skidding of the car during braking;
- Skrip and others extraneous sounds during braking;
- Vibrations of the steering wheel;
- The light bulb on dashboard.
Why is low brake fluid bad?
First, let's figure out what is dangerous an insufficient amount brake fluid. Low level usually indicates a leak that has occurred in the brake system. The danger here is that the car's brakes could fail, which could result in a serious accident and put the lives of everyone in the car at risk at that moment.
How do you check the brake fluid level yourself?
There are two main methods for checking brake fluid: checking its level (quantity) and quality.
There are two ways to check the brake fluid level. The first way is with the help of devices. If the brake fluid level approaches the “minimum” mark, then a light on the dashboard lights up. In this case, at the first opportunity, it is necessary to stop the car and add fluid, and then do not postpone the trip to service center for diagnosing the entire braking system.
The second way is a visual check. You just need to check the fluid level manually. To do this, you need to get into the engine compartment of the car. Before doing this, check that the car's engine is turned off and the vehicle itself is on a level surface. IN engine compartment there is a tank in which liquid is poured. If its level is located in the middle between the "minimum" and "maximum" marks, then it is necessary to add brake fluid to the upper mark. If during the check you saw that there is less liquid in the tank than it was after the last filling, then inspect the tank. With a high degree of probability, you will find a leak. If you yourself could not find it, then you should immediately go for a consultation to a car repair shop.
Remember that brake fluid is not consumed during operation if everything is in order with the machine!
If everything is in order with the brake fluid level, then the next step is to check the sensor, which is triggered if the brake fluid level reaches a critical level. To check, you need to turn on the ignition, and then press the button on the plug located on the tank. After pressing on the dashboard, a light should come on, informing the driver about the critical level of brake fluid. If this does not happen, then the sensor is not working.
Also, the problem may arise not only due to leakage, but also due to the brake fluid itself. Even if the liquid level is maintained during operation, about 2 times a year it must be replaced with fresh, regardless of the distance traveled.
If the car has driven about 50 thousand kilometers, then the fluid should also be changed. You can also do it yourself, but taking precautions:
- First, the liquid is toxic. It is worth protecting your hands when working, and also do not need to pour old fluid along with everyday waste.
- Secondly, the used brake fluid must not be allowed to come into contact with other parts of the machine.
During operation, the brake fluid becomes contaminated, saturated with moisture (it is very hygroscopic!) and air. This may cause damage to parts. In addition, when the water content in the brake fluid reaches a certain level, it ceases to function.
To test the quality of brake fluid, there is a special device that measures its boiling point. If, after checking, the device showed a temperature above 175 degrees, then everything is in order with the liquid, if the indicator ranges from 175 and 165, then this liquid can still be left in the tank, but it is worth remembering that its efficiency is somewhat lower.
If the result is below 165, then the brake fluid should be changed as soon as possible. Such a tester can also be used after purchasing a new brake fluid. For some manufacturers, the boiling point of the liquid immediately fluctuates around 170 degrees.
Pros and cons of these methods
Each method of checking the brake fluid level has its pros and cons.
As for the first method, there is one plus here - saving time. No need to check the reservoir before each trip, or at least every other time. The car will tell you when the level is too low. This is quite convenient, but one cannot but mention the disadvantage. If the light on the panel lights up, this means an almost critical fluid level that needs to be raised as quickly as possible. But after all, the driver does not always have the opportunity to stop the car and fix the problem. In addition, something may be wrong with the bulb itself or the level drop sensor. Therefore, relying solely on the dashboard, the driver exposes himself and passengers to a certain risk.
The advantage of manually checking the brake fluid is greater safety if the driver checks regularly. If there is any problem, then there is a much better chance of fixing it before the trip. The disadvantage here is quite obvious: before getting behind the wheel, the driver each time will have to spend some time checking.
Of course for more security it is better to regularly check the brake fluid reservoir manually, but at the same time do not forget about the readings of the instruments, just as you should not forget about the quality of the brake fluid. There is only one way to check the quality of brake fluid. Its advantage is that with the help of a tester you can quickly determine the quality of the liquid, but the only drawback is that you need to buy a tester. average price such a device fluctuates around two thousand rubles, really reliable and high-quality models cost almost five thousand.
Video: how to check the brake fluid level?
Conclusion
Now you know how to check brake fluid. It is necessary to constantly monitor the level of the brake fluid, since the safety of people in the car directly depends on its condition. You can monitor the level of brake fluid in the reservoir based on the dashboard readings, or you can manually check the reservoir located in the engine compartment. For a greater guarantee of safety, these methods should be combined, as well as remembering essential little things, such as a light on the panel and a sensor on the tank cap. Also, don't forget about timely replacement old brake fluid with new fluid to keep your vehicle running efficiently and safely.
Checking the effectiveness of the brake system
In accordance with clause 1.1 of the "List of malfunctions and conditions under which the operation of vehicles is prohibited" braking distances car with a single press on the brake pedal from a speed of 40 km / h should be no more than 12.2 m.
The test is carried out on a dry clean horizontal section of the road with a concrete or asphalt surface.
The brake system of the car must be tight.
The brake fluid level in the reservoir must be at the MAX mark.
1. Accelerate the car up to 40 km/h.
2. Press the brake pedal to the stop, blocking the wheels, and hold it in this position until the car comes to a complete stop.
3. Measure the stopping distance of the car with a tape measure. If the length is more than 12.2 m, the operation of the brake system is not effective enough.
4. To eliminate the influence of side effects, the braking distance is checked by accelerating the car in two opposite directions in the same section
Checking the brake fluid level
The brake fluid level is checked periodically: daily during vehicle operation, at each maintenance, after carrying out operations to bleed the hydraulic drive of the brake system and replace the brake fluid, in case of fire on the instrument panel control lamp, signaling insufficient level brake fluid in the master cylinder reservoir.
2. With a rag we remove dirt from the reservoir of the main brake cylinder.
3. Visually check the level of brake fluid in the reservoir. It must be between MIN marks and MAX on the tank body.
4. Check the degree of wear of the front and rear brake pads brake mechanisms.
5. If the wear of the brake pads is within normal limits, and the fluid level in the reservoir is below the MIN mark, then disconnect the tip of the wiring harness from the brake fluid level emergency drop sensor, unscrew and remove the reservoir cap.
6. Add new brake fluid to the reservoir to the MAX mark (when installing the reservoir cap, the sensor float will sink into the liquid and its level will rise).
7. Tightly close the tank lid.
8. Connect the wiring harness block to the sensor connector.
9. We check the operation of the brake fluid emergency level sensor: with the ignition on, we press on top of the rubber lining of the reservoir lid. If the sensor is OK, the control lamp on the instrument panel will light up.
Checking brake pad wear
Checking the degree of wear of the brake pads of the front brake mechanisms is carried out in the following sequence.
1. We install the car on a viewing ditch.
2. Remove the front wheels.
3. When checking the pads of the left brake mechanism, we completely turn steering wheel to the left, and when checking the pads of the right brake mechanism - to the right.
4. Through the inspection hole in the caliper movable bracket, we visually determine the thickness of the brake pad linings.
If the lining thickness of at least one pad is less than 1.5 mm, we change all brake pads of the brake mechanisms of the right and left wheels.
5. At the same time, we check the mobility of the pistons brake cylinders.
When the piston is soured, we replace the cylinder.
A flashlight is required to perform a wear check on the rear brake pads.
1. We prepare the car for work.
2. Using a slotted screwdriver, remove the rubber plug of the inspection hole in the support shield of the brake mechanism rear wheel.
The braking system is necessary to quickly change speed or completely stop the car and hold it in place when parked. To do this, the car has such types of brake systems as working, parking, spare and auxiliary system(retarder).
In cases where you have doubts about the serviceability, then you need to check them. After all, it will be regrettable if they are really faulty, and there will be a concrete slab ahead or something worse than someone's Lexus.
| The content of the article: |
How to test disc brakes?
When checking disc brakes, as a rule, the thickness of the pads on the pads is measured first. In cases where a steel base plate is visible, this tells us that it is necessary to replace the brake pads.
When checking disc brakes for serviceability, perform the following steps.
1) . Jack up the car, remove front wheel. IN this case you should also not forget about safety, that is, you should use wheel shoes.
2). Before you is a brake disc, it is also a rotor. We run our hand along the two sides of the disk from the center to the edge. In this way it will be possible to determine the wear brake disc. If you feel uneven wear or the disc is very worn, then you should contact the master to determine the possibility of further operation of the brake disc (after growth) or you will have to replace it.
3) . Next, we check stopping support. Just remember, if the car was recently used, the caliper will be hot. But if not, then we grab it with our hands and shake it from side to side, which will make sure that the mounting studs and eyes are in good condition.
4) . Pay attention to the brake pads. In cases where the thickness of the linings of the brake pads is only 30 percent of the thickness of the linings on the new ones, then we replace them with new ones.
5) . Before replacing the pads with new ones, we recess the caliper pistons into the body so that the caliper can easily move from the brake disc. After that, unscrew one of the mounting bolts, move the caliper and replace the pads. Assemble in reverse order.
How to check drum brakes?
1). We put the car on a flat area and put stops under the wheels. We shoot from parking brake, loosen the bolts of the rear wheel, put it on the jack (observing all necessary measures precautions) and remove.
2) . Remove the brake drum. Unscrew the bolts, insert them into technological hole and wrap until the drum separates.
3) . To facilitate the removal and installation process brake drum, in the gap between the hub and the drum we apply the drug "Unisma - 1" for about 15 minutes.
4) . In cases where the brake drum has completely grown, especially when the working brake cylinder is not working, you can use the following option. We drill several holes in the drum with a diameter of 2-3 mm, close to the protruding part of the axle shaft. We start drilling at the junction of the drum and the axle shaft, through which the brake fluid penetrates into the contact zone. And this, in turn, can facilitate the process of removing the drum.
5) . Having removed the brake drum, check the condition of the brake pads with linings and working surface brake drum. Broken, worn, deformed pads are replaced with new ones.
How to check the handbrake?
As a rule, the failure of the handbrake mechanism consists in the oxidation of steel cables that prevent it from moving along the shell, in the rupture of individual threads or in their excessive elongation.
Checking and adjusting the parking brake is a very important point in car maintenance. A broken parking brake can be the most unfortunate outcome, but it is the easiest to detect.
How to check?
1) . To check the parking brake of the car, it is advisable to drive it into a pit or raise it on a lift. But in cases where this is still not possible, then you can climb under the bottom, taking a tool with you to remove the protective pad that covers the parking brake mechanism from below.
2) . The operation itself is best, of course, carried out with an assistant who will periodically raise and lower the parking brake lever.
3) . Being under the car, we check how well the cables in the sheath go, whether there is rust, deposits on their surface, whether torn threads are visible.
4) . In cases where you want to make a more detailed inspection, the cables will already have to be completely removed.
Causes of malfunctions .
1) . If the handbrake handle moves easily enough, the return springs can be heard in the drums, but when the lever is in top point the wheels do not lock, it means that the cables are very stretched. You can solve the problem by adjusting. In extreme cases, we make a replacement.
2) . In cases where, when trying to “turn on” the handbrake, the lever does not move, rises with considerable effort, or when it is lowered, it does not unlock rear wheels, then most likely the cables in the sheath “soured” or there was a partial rupture of the threads that prevent the free movement of the cable.
How to check the vacuum brake booster?
Method number 1.
1). We start the car engine, and after about 10 minutes we turn it off. Then press the brake pedal all the way. With a properly functioning element, the system will work once and the vacuum will attract the diaphragm spring. With subsequent presses, the pressure in the system will be cut off.
2) . The pedal travel will decrease and decrease. But we need to provide braking force at the first pressing. And if the device coped with the test, then everything is in order with it.
3) . Important point: Pedal should go down on next start (if pressed to the floor). This indicates that sufficient pressure has accumulated in the system. Both circuits are correct.
Method number 2.
1) . We start the engine and press the pedal, after which we turn off the engine. In this case, the pedal must be kept in the floor, we lower it only after 20 - 30 seconds.
2) . The mechanism must then return to its original position, since excessive pressure has formed in the circuit. But in cases where the pedal “failed”, then this tells us that there is a leak in the vacuum chamber.
3) . In this case, we either repair or replace vacuum booster brakes.
How to check the brake pedal travel?
Reduced free play on the vehicle's brake pedal can cause the wheels to brake, which in turn can lead to overheating of the brakes. As a result, the car will not accelerate well.
1) . Gently press the brake pedal until you feel resistance. In this position, a 3 mm thick plate is inserted between the switch buffer and the pedal bracket. In cases where the plate between the bracket and the buffer is not included or remains between them big gap(more than 2 mm), then we adjust freewheel brake pedals.
2) . Keeping the pedal depressed, loosen the two nuts that secure the brake light switch and move the switch to achieve free play of the pedal. After adjustment, the bracket should rest against the buffer of the switch (with the pedal released). While holding the pedal in this position, tighten the fastening nuts.
3) . In cases where you still failed to adjust the pedal stroke in this way, you will have to contact a specialist.
How to check brake fluid?
On vehicles manufactured from the mid-1980s to the present day, the container attached to the brake master cylinder is transparent. Thanks to its transparency, there is no need to unscrew the cap to check the brake fluid level.
When checking the fluid level, remember that it must be between the "MIN" (minimum mark) and "MAX" (maximum mark) marks. That is, not lower than the minimum mark and not higher than the maximum.
At the same time, it is also worth noting the fact that on some car models (including older ones), the brake fluid container is metallic and not transparent. In this case, to check the fluid level, you will already have to remove the cover.
After unscrewing the cap, you should look at the solid line marked inside the tank. But in case this line is still not visible, then you should make sure that the liquid level is about 6 mm from the top of the tank. Otherwise, you will need to add liquid to the required level.
Brake system: maintenance secrets
Common Brake Problems . One of the most common problems is squealing when braking. This can be a consequence of both the erasing of the pads and their distortion when metal surfaces are rubbed.
The second problem may be vibration when braking the steering wheel or car body. In the first case, this may be due to a malfunction of the front brakes, and in the second - with the rear ones.
If the car pulls to the side when braking, then most likely the problem lies in one of the calipers, which has become unusable.
In the process of continuous friction, pad jamming can also occur, which can cause strong heating caliper parts.
Caliper lubrication requirements .
1) . Caliper grease must withstand high temperatures because due to heavy loads, parts of the brake system can heat up to 500 C. Otherwise, it may leak or harden, which can lead to jamming of the caliper.
2) . The second factor to be taken into account is low temperatures. In Russia in winter period The climate is quite harsh. In some regions, the temperature can drop to -30 degrees and below. And some lubricants can not withstand temperatures of -15 degrees.
3)
. Another factor is the effect of lubrication on the rubber parts of the caliper, such as the boot. This part is designed to protect the guides from getting dirt and reagents on them, which can also directly affect the brake system. The boot should not change both its size and rigidity.
Conclusion
In order for the brake system of the car to work properly at all times, you should carefully monitor the condition of your vehicle. vehicle on your own, ask for a similar service more experienced drivers, or periodically visit the service station. In this case, the risk of a malfunction of the brake system approaches zero, since its device is quite simple and there is practically nothing to break.
