Slowing down the speed of the car up to a stop (braking) occurs when the pads rub against the discs or drums. These parts come into contact when the brake pedal is depressed. Motorists most often do not think about how to determine wear brake pads, such a question usually arises when problems with the system become noticeable. Pads wear out faster because friction linings are their main part during braking, which are softer than metal and wear out faster. It is important to understand in time why the mechanism began to work worse, and urgently make repairs. At what wear to change the brake pads and how to determine their wear, you will learn from this article.
1 — brake disk; 2 - guide pads; 3 - support; 4 - brake pads; 5 - cylinder; 6 - piston; 7 - pad wear indicator; 8 - sealing ring; 9 - protective cover of the guide pin; 10 - guide pin; 11 - protective cover.
What causes pads to wear out?
For different models machines have a certain service life of the brake bars. But this does not mean that they cannot fail before the car “runs” the kilometers indicated in the manual. There are several factors due to which the pads become unusable before the set resource expires:
- driving mode. The urban driving cycle leads to wear of parts faster due to frequent stops at traffic lights.
- The degree of loading. How more cargo in the trunk of a car, the faster the wear of the rear brake pads. At the same time, this takes some of the pressure off the front brake pads, which means they last longer.
The average service life for these elements is about 10,000 km, after which they are changed. But signs of brake pad wear can appear earlier and need to be known.
What indirectly indicates pad wear?
How do you know that these parts have fallen into disrepair without fiddling with the inspection? On many modern cars an electronic brake pad wear sensor is already being installed, which will warn the motorist in time that the friction linings of the elements are no longer suitable for work. Except electronic sensor, there are also mechanical ones, which are a metal strip and are attached below the lining. In this case, the erasing of the friction layer can be recognized by the characteristic rattle and whistle, which will be well heard when you press the pedal. In this case, the operation of the brakes will be somewhat impaired, but not to a critical level, and the driver will be able to change faulty auto parts in a timely manner. Mechanical signaling devices can be installed on one wheel (usually front), two (front or rear) or all.
The presence of a brake pad wear indicator greatly simplifies the diagnosis. If they don't exist, extraneous sounds it will be possible to hear only when the pads are worn to the limit stage, and the quality of braking is significantly reduced: the pedal will have to be pressed with more force, and in addition, the braking distance will increase.
Brake pad wear sensor
If particles of road dirt are between the disc and the pad, this will lead to accelerated wear of the elements. brake mechanism. Signs of such problems will be the beating of the brake pedal when you press it.
If there is uneven wear of the brake pads, in which the friction layer on one of the elements is erased faster, you can find out about this by skidding the car to the side during braking. A sharp pedal press in this case can cause the car to be thrown off the road, especially on a wet surface. Therefore, uneven wear is very dangerous, and, having noticed it, the car must be urgently repaired.
You can also learn about the wear limit if the depressed pedal remains in the same position after releasing. This happens when the friction layer is almost completely erased, and the metal of the bar, heated by friction, seizes with the disc. But precise definition the causes of malfunctions are possible only during inspection, since these signs can also indicate the failure of other elements of the brake system.
Immediate signs of pad failure
Having noticed any of the above signals, do not delay the repair - the extreme wear of the elements of the brake system makes driving a car, without exaggeration, deadly. It is best if diagnostics and, if necessary, replacement of spare parts, are carried out by professionals at a car service: this will guarantee the correctness of the check. But, if this is not possible, or you prefer to repair " iron horse» with your own hands, then carry out a visual inspection to determine the cause of wear brake elements you can do it yourself.
The fact that the strips are unsuitable for further work can be recognized by the following signs:
- The thickness of the friction layer has fallen below the permissible value set by the manufacturer.
- The thickness of the brake disc has decreased less than the maximum allowable value(You can measure this parameter, as in the previous case, using a micrometer).
- Traces were found on the friction lining, on the base of the brake pad or disc mechanical damage in the form of cracks or depressions.
- A protruding rim appeared on the outer edge of the block.
- The disk is skewed.
- A coal deposit appeared on the surface of the disk, which indicates that the surface began to collapse.
About the need urgent replacement the braking system strips are indicated by the appearance of a dark-colored coating under the wheel cap containing small metal particles. This indicates the complete erasure of the friction layer and the fact that the base of the part has already begun to be erased.
In no case should repairs be postponed when problems are discovered, since the safety of the car, driver and passengers directly depends on the health of the brake system.
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In Lada Kalina cars, with the exception of the "Sport" version on rear axle drum brakes are installed. Eternal disputes about whether they are better than disk ones or worse do not stop. However, the braking system drum type there is one indisputable plus - friction linings wear out more slowly. And yet, it is necessary to check the condition of the rear brake pads and drums regularly - there are also some nuances here.
Advantages and disadvantages of drum brakes
drum brakes indispensable for trucks and buses, as they allow to achieve the necessary braking force for vehicles with a large mass. The reasons for using them on the rear axle of cars are somewhat different.
- Drum brakes simplify mechanism design parking brake.
- They are less subject to wear due to the larger contact area of the friction linings and drums.
- Finally, they are less critical to road conditions, as they are reliably protected from dust and moisture ingress.
The disadvantages of drum brakes include their slower response and less stability, which is the result of uneven contact between the friction lining and the drum. Also, a disadvantage of drum brakes can be considered their more complex design. So how do you check the condition of the rear brake pads?
Diagnosis of the state of the rear brake pads
The design of the brake system in Kalina assumes the greatest load on the front axle. When you press the pedal front brake"grabs" a little faster. In addition, the contact area of the front brake pads and discs is smaller than the rear pads and drums. That is why the rear brakes can be enough for 60 (or more) thousand kilometers, provided that you drive carefully. Checking the rear brake pads consists in the minimum allowable thickness of the friction linings, which is 1.5 mm. However, it is better not to bring them to such a state.
The service life of brake drums largely depends on the type of pads. If they are soft, then the drums wear out more slowly, but the pads themselves will have to be changed more often. The maximum allowable inner diameter of the brake drum on Kalina is 201.5 mm. If the surface has worn off more, the drums require immediate replacement. If the diameter is very close to this value, it is better to change the drums immediately - it still provides for their removal.
There are a couple of nuances, because of which, in practice, you have to think about replacing the rear brake pads a little more often. The first of these is a slightly more complex design of the pads themselves. The surface of the base and friction lining in this case semicircular, which complicates their manufacture and reduces the reliability of fastening. Sometimes it happens that friction linings that have not yet completely worn out move away from the base, which requires their immediate replacement. Especially often this happens with low-quality pads.
Automobile brakes are subjected to serious stress during operation, which is natural, given the severity of the vehicle, which must be stopped at any speed. The damping of the load leads to mechanical wear of the parts of the brake system, in which the pads suffer more than others. When you press the brake pedal, they are pressed against the brake discs. If the car is in motion, friction occurs, which is impossible without mechanical wear.
According to the recommendations, the brake pads on cars must be changed every 10 thousand kilometers so that the car's braking quality is always maximum. At the same time, it should be noted that the recommendations give average figures for the pad change cycle, while different drivers wear out mechanical part brakes can different speed. With a calm driving style, the pads can last up to 20 thousand kilometers, while with regular sharp pressing on the brake pedal, they will wear out to critical values after 4-5 thousand kilometers.
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Worn brake pads are a danger to the driver of the car, its passengers and other people. In no case should you hit the road if the brakes are faulty, and the worn pads must be urgently replaced. But how to determine the wear of the brake pads and the need to replace them? This can be done directly from the inside of the car while driving or by external signs.
There are several characteristic features, which will tell the driver that it is necessary to think about replacing the pads:
If the sounded signs are not enough to determine the wear of the pads, a visual inspection can be carried out.
Drivers are advised to check the condition of the brake pads every 2-3 thousand kilometers. For their visual inspection it is necessary to remove the wheel cap and pay attention to the presence of plaque on the wheels or directly on the brake pads. If there is a gray coating, then from this we can conclude that it is worn out in this moment pad lining. Until she wears out brake system will work without obvious failures.
If you find metal particles in a gray coating, it means that the lining is out of order, and the process of abrasion of the pad metal has begun. In such a situation, it is urgent to replace this component of the brake system.
Smooth braking of the car is achieved due to the simultaneous operation of the brake system on all wheels. Replacement pads provided in pairs for the front and rear axles of the car. The pads located on the rear axle of the machine are less subject to wear than the front ones, and they need to be changed, on average, 3 times less often.
Instruction
Each vehicle has its own criteria for the frequency of brake replacement. pads. Basically, motorists believe that the pads need to be replaced after 8-10 thousand kilometers. This indicator is general and should not be completely guided by it. Each driver has an individual driving style: someone drives a car calmly, in this case the pads can work up to 20 thousand kilometers, and for amateurs fast driving and sudden stops, you have to change the pads after 5-6 thousand runs. In addition, there are many parameters that contribute to wear at pads: the quality of the brake elements, environment, temperature fluctuations, etc.
About wear e pads indicates the presence of brake dust mixed with metal chips on rims, as well as very sharp, or, conversely, excessively weak braking, the presence of a beat at the moment of braking. If your car has similar problems, check the brake pads.
To check the degree wear and brake pads and front brake mechanisms, install the car on viewing hole or jack.
Unscrew the front wheels with a telescopic wrench. When checking pads brake mechanism on the left, turn the steering wheel to the left, and when checking the right brake elements - steering wheel to the right.
Determine the thickness of the brake pads pads through the inspection hole in the caliper movable bracket. If the friction lining thickness is 1.5 mm or less, the pads should be replaced.
For check pads rear brake mechanism, place a jack under the rear wheels and unscrew them, and also remove brake drum.
Use a caliper or ruler to measure the thickness of the friction linings. If it is less than 1.5 mm, replace the rear brake pads as well.
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note
It is necessary to change the pads in the following cases: The thickness of the pads is less than 1.5mm, the pads are poorly connected to the base, the surface of the pads is oily.
Sources:
- brake pad wear
- Video of replacing the front brake pads VAZ 2107 2106 2104
Brake pads are the second most frequently changed after oil. consumable in the car. If you miss the moment when you need to replace them, this can turn into big trouble for the car. In addition, smart technology warns in advance when it is necessary to change them.
Instruction
In the USA and Western Europe wear tires are checked with the help of coins: one dollar, one cent, 1 euro coin. The coin is inserted into the most worn part of the tire, and the protruding parts of the image determine residual tread. For example, on the dollar - this is Washington's hair, on the one-cent coin - the crown of Lincoln, on the euro - the gold part of the coin should be buried in the tread. You can use the domestic two-ruble coin. Insert the coin head down into the tread groove. If the tops are recessed or close to the surface tires- everything is fine, yet.
From premature wear tires will help their timely interchange.
The braking system of a car is the most important node and requires proper care and attention. In case of wear brake pads on rear pads to the rivet heads, or when the diameter of a pair of pads has become much smaller than the inner diameter of the brake drum, they should be replaced so that there is no unpleasant consequences.
You will need
- - hammer;
- - chisel;
- - drill and drill;
- - pneumatic press;
- - lathe.
Instruction
Install the car on a lift or a viewing hole. In the latter case, fix the front wheels by placing stops under them on both sides. Jack up the car and remove in sequence - the wheel, brake drum and brake pads. Inspect them if their body has significant defects that may interfere with their functions, or the size of the friction linings is smaller than allowed, replace them.
Use a hammer and chisel to cut off the worn friction lining, having previously secured the brake shoe in a vise. After that, knock out the rivets from its holes.
Choose a friction pad that is the correct size and fits snugly to the surface. Drill appropriate holes in it, using the brake shoe as a template if none are available. To do this, select the diameter of the drill. If it is 5 mm at the rivet, then 5.3-5.5 mm should be taken, if 8 mm, then 8.3-8.5 mm, respectively. Secure the friction lining to the brake shoe using zip ties and drill holes.
Perform countersinking. To do this, select a drill that has a diameter slightly larger than the rivet head. Drill the previously obtained holes so that there is a gap of 2-3 mm.
Install the rivets in the holes and flare them. Attach the pad firmly to the block. Then flare with a pneumatic press. It should be ensured that the diameter of the pair of shoes is less than 3 mm of the diameter of the brake drum. Otherwise, bore the pads on a lathe. When there is a wear on the rear brake drum, then turn it into a repair size.
During the operation of the car, the brake pads wear out. Despite the guaranteed mileage up to another replacement front pads 10,000 km, and rear drums - 25,000 km, it is necessary to check them periodically wear. This event will also help identify the need for maintenance of the brake calipers.
You will need
- - jack;
- - a set of keys;
- - flat screwdriver;
- - hammer;
- - flashlight;
- - 2 bolts M8.
Instruction
Turn the steering wheel in the direction on which you will look at the value wear and brake pads, tighten the handbrake and remove front wheel. The brake caliper has a viewing window through which you can see the remaining layer of friction material - Ferodo. If the material is not visible under the available lighting, shine a flashlight there. On new pads, the thickness of the friction linings in most cases is 10mm. When their thickness reaches 2mm, replace the pads.
In addition to the absolute thickness of the material, its uniformity is of great importance. wear A. If wear pads occurs at an angle, which means that one of the guides brake caliper jammed. If one pad wears much more, then both guides are jammed. Troubleshoot and replace such pads, then install the wheel.
Check the second wheel in the same way, if possible at this stage. After checking the front brake pads, check the rear ones as well. Drum brakes are fully mechanical and cannot be inspected without removing the brake drums.
Before lifting rear wheel jack, put bars under the front wheel - one in front, the other in the back. This is necessary because the parking brake does not apply to the front. With the wheel up, sit in the driver's seat and press the brake pedal. While holding it, remove the machine and slowly release the pedal. Make sure it is securely in place.
Remove the rear wheel. Using two M8 bolts, press the brake drum from its seat. This is done as follows: in 2 holes on the drum, wrap the M8 bolts. Gradually tightening them with a socket wrench, achieve the most even descent of the drum from its seat.
Correct it if necessary light blows hammer through a plywood board. With a large wear A shoulder is formed on the drum, which prevents the removal of the drum. In this case, through the hole in the drum or in the protective apron, using a flat screwdriver, turning adjusting bolt, remove the brake pads. This process is inconvenient in that you have to touch the pads, since no additional viewing windows are provided.
After removing the brake drum, unscrew the M8 bolts from it. Inspect the brake pads. The initial thickness of the friction coating is 3-4 mm, depending on the size of the brake mechanism. If the residual coating thickness in any place of the pad is 0.5 mm or less, replace the brake pads. unevenness wear and drum brake pads is no reason to replace them.
Install the brake drum, adjust the brake shoes. This must be done in order not to different strength braking on and left . This is done simply: using a flat screwdriver, through the window in the drum or in the protective apron, turn the adjusting wheel until the pads touch the drum. The clamping force must be minimal so that the drum rotates freely.
Sources:
- brake pad wear
Often, users of personal computers have certain problems associated with the use of hard drives. One of the most common is to run its check when Windows boots.
You will need
- - Confident PC user skills.
Instruction
Wait for the verification to finish hard drive. This may take a long time, it all depends on its volume. After checking and downloading operating system open the Windows Registry Editor. The registry of the operating system is one of its main components, which is responsible for almost all aspects of its operation. The same applies to the launch of Scan Disc when the computer boots up - information about enabling this utility is also written in the registry, this information is in text format, so it is easy to edit. The registry editor is opened using the regedit command in the Run utility field, which, in turn. Runs from the start menu.
Look in the registry for an entry to run the hard drive checker. To do this, in the folder tree on the left, open the drop-down directory HKEY_LOCAL_MACHINE. Next, navigate to SYSTEM/CurrentControlSet/Control/Session Manager and select the entry called BootExecute on the left side of the screen. The value of this setting should be displayed in the right part of the window. Select the text, copy it and paste it into a text document.
Save it to any directory on your computer. This is necessary so that you can return to the previous settings if suddenly the new ones do not lead to positive changes. After that, delete the data regarding this setting from the registry. Be extremely careful when performing certain manipulations with the Windows Registry Editor, as this can be reflected in all aspects of the computer.
Restart your computer after making changes in the operating system's registry editor. If the disk check does not appear on your screen before starting Windows, then you did everything right. Just in case of a hard drive, using special third-party utilities for this, which you can find on the Internet.
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Helpful advice
Be extremely careful when working with the registry.
Need to replace brake pads BMW cars can be recognized by the indicator on the instrument panel, which lights up when the degree of wear of the pads approaches a critical value. If a brake system with six piston calipers (or a more complex modification) is not installed on the car, pad replacement work can be done independently, without the use of special equipment.
In order for the brake system to always be in good condition, it is necessary to constantly monitor its components. Since the brake pads work exclusively for friction, they wear out faster than other parts. It is impossible to say exactly when wear and tear will occur, the conditionally operational life of their work is from 8 to 15 tons of kilometers during normal driving without “recklessness”. Checking the brake pads allows you to roughly understand when to replace.
Brake system
Each vehicle is equipped with:
- brake mechanism;
- parking brake;
- spare brake. Applied in emergency cases, in case of failure of the main brakes. IN cars this is usually implemented by dividing the brake system into several circuits diagonally or front / rear.
The brake system consists of a drive and a braking mechanism with a drum or disc, as well as brake shoes. Drum brakes are now used less often, although they last longer. Today, almost all cars have a disk braking device, such a system is considered fixed and has a caliper and two pads that are stable in one position. When the brake pedal is pressed, they compress the disc. There are also systems with a floating block, they are more complicated. During braking, the caliper piston touches one of them, it moves away, leans against the disc and shifts it to the other, after which a clamp occurs.
The brake pad has two components: a frame and a friction lining. In short, it is the lining that performs the main task of braking, stopping the brake disc with its friction. Front brake pads wear out two to three times faster than rear ones. This is because a large load during braking falls on the mechanism of the front wheels, there is a redistribution of the weight of the car on the front axle. The wear rate is directly affected by:
It is noteworthy that in winter time year, replacement is less frequent, which indicates that there are few maneuvers during movement in winter.
signs of wear
Sometimes, in order to simply assess the condition of the linings, it is not at all necessary to get into the brake system. Many are interested in how to check the brake pads without removing the wheels? Depreciation can be determined by the following signs:
Checking the pads without removing the wheel
Checking brake pad wear is easy, especially when vehicle stand alloy wheels with large holes through which the brake assembly is visible. As a rule, only the outer block is visible. If you determine its thickness visually, then 1.5–2 millimeters is considered critical. When, without even removing the wheel, you notice that the lining thickness is less than 5 millimeters, this is a reason to replace it. If the holes on the wheel are too small, and the brake mechanism is poorly visible, you need to start dismantling the wheel. When nothing interferes with the review, it is easy to assess the condition of the second lining and, along the way, the brake disc.
Proper Pad and Disc Inspection Process
Before checking, view the table of indicators allowable sizes brake parts. When the data matches, start making the replacement. The process is divided into the following steps:
Parts need to be replaced if:
- linings in oil;
- products thinner than 1.5 mm;
- pads are loosely connected to the base;
- discs must be replaced if there are scratches or shape deformation.
Replacing the front brake pads
Replacing the rear brake pads
The replacement process is almost the same:
- To immobilize the car, put it into gear. You cannot turn on the handbrake, as it will press the pads against the disc, and replacement will not work. For safety, we put bars under the wheels.
- We remove the wheel, remove the guide pins with a key No. 12.
- We remove the drum.
- Disconnect the springs from the pads.
- We take out the front block, remove the drive lever from the cable and remove it. Also do from the back.
- Now we install new parts exactly the opposite.
