Pads whistle during braking after replacement - the reasons why new (or only slightly worn out) brake linings make loud sounds: squeak, howl, and so on.
Sometimes this whistle reaches such force that it becomes embarrassing to drive. Naturally, most motorists in this situation are perplexed why this happens if the pads are new (or have only covered 500-1000 km).
In short, the table contains the main reasons. As you can see, there are only three of them. Below they will be discussed in more detail and in detail.
|
Cause |
Probability |
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Incorrect installation of pads at the service station |
|
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Worn brake discs |
|
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Poor quality pads or not yet worn |
Now you should go over in detail for each malfunction.
Reason number 1: incorrect installation of pads at the service station
The loud whistle of new or almost new pads in very many cases is a consequence of the handiwork of the craftsmen. The replacement procedure is very simple, but they also manage to make mistakes in it.
First, the back of the pads should be greased with a special anti-squeak paste. In extreme cases - copper. The paste does not allow creaking to develop, thickens over time, and dampens resonant vibrations, so that even if the discs are killed, the sound becomes quieter. It must be applied with a thin layer so that it does not fall on the piston (it is lubricated with a separate grease). Most of the services neglect this procedure; they simply save on lubricants.
Secondly, some types of cars (for example, old Mercedes, Audi) have a barely noticeable bevel on the piston. It was specially made to get rid of the squeak so that the dust is removed from the disk. Naturally, 99% of the craftsmen do not look at the manual for a particular car, thinking that all the pads change in the same way, and do not even know about the orientation of the piston.
Thirdly, the pads are simply put in one place. They forget to put a plate, a spacer, put on larger pads, which, when erased, form a lot of abrasive, leading to a creak. If the wheel is very hot, then it is so.
Some would-be craftsmen also tear off the protective anti-squeak layer from the back of the shoe, taking it for a protective film.
The verdict here is one - to change it with a specialized master, or independently according to the instructions (there is nothing complicated here).
Reason # 2: worn discs
The pads can whistle like hell if the discs have grooves, or they are already worn out at the end. This is especially true in hot and dry weather. Excessive dust gets stuck in the grooves of the excavation, and a creak begins.
Here, even if the pads are new, nothing can be done. It is necessary to grind, or completely change the disks. This is the only way out.
Often it is the discs that give a squeak to the sensations as "metal on metal". If at the same time there are vibrations on the steering wheel or the car, you cannot continue driving. This means that the wear is enormous, and braking can become ineffective.
By the way, the discs can be driven due to temperature differences (for example, when driving in the rain down a serpentine road with frequent braking, or when the block is not fully squeezed out).
In general, a complete diagnosis of the braking system is required. And it is not necessary to go to the service station for this - it is enough to remove the wheel, rotate the disc, assess the degree of its wear.
Reason number 3: poor quality pads
Today, almost all spare parts of such a plan are of more or less quality, but occasionally it happens that the shoe is either too hard and does not have an anti-squeak lining, or it is very soft and clogs everything with dust.
Some pads do not rub in even after 1000 km. Some wear out after 1000 km. But this happens very rarely.
To amuse yourself with hopes that a repeated replacement will be able to resolve the issue is possible only if the brake discs are new, and there is no doubt about the installation.
Otherwise, most of even Turkish kih or Chinese pads are quite tolerable inhibited and should not whistle if there is a working system.
How to get rid of whistling brakes temporarily
To completely get rid of the whistle of the pads, you need to tidy up the brake system. But there are also short-term temporary options.
Immediately I would like to note that to smear pads and discs with solid oil, machine oil, silicone is a joke. In this case, the brakes disappear completely. Nevertheless, many people take this joke for the truth.
Autochemistry sells special aerosols and adhesives for pads, but all of them are mainly intended for application on reverse side... That is, if you really remove the wheel and disassemble everything, it is better to use copper grease or a squeak paste than paying exorbitant prices for an aerosol.
To temporarily eliminate the whistling of the pads, there are the following remedies:
- Water. She needs to spray on the disc, you can wipe it with a damp cloth. It is advisable to spray only before the trip.
- Window cleaner. Spray a small amount onto the disc. Ammonium or regular alcohol is also suitable.
- Brake fluid. A small amount per disc, or the pads themselves. It is worth remembering that it eats paint!
- Solvent. Or acetone. Carburetor cleaner may be splashed on.
Attention! All these means deteriorate the quality of braking for a certain time and do not last long.
The design of the car assumes the presence of many components and assemblies. All of them are closely interconnected. The serviceability of such a unit as brakes is above all. After all, the life of the driver and his passengers depends, without exaggeration, on this. What to do if the car squeaks during operation? Let's try to figure it out.
Is it dangerous?
There is no definite answer to this question. The fact is that the squeak of the brakes is possible both on new ones and on worn out pads... To determine their residual life, you need to look at the thickness of the friction material. On modern elements the manufacturer makes special "flags" - wear indicators between two parts of the pads.
If this part equaled the entire plane of the pads, this indicates an upcoming replacement. They creak in a car with pretty worn-out elements. Sometimes it comes to the point that nothing remains in the shoe, except for the metal case.
As a result, they can simply jam - the car will skid. It is very dangerous. Change items on time. When to change brake pads? Usually they serve 20-25 thousand kilometers. However, it all depends on the driving style. With active frequent braking, the life of the pads is halved. Therefore, always look at their thickness visually. If the remainder is 3-5 millimeters, the elements need to be changed urgently.
Why do brakes squeak after replacement?
It happens that when installing new elements, a characteristic grinding sound remains. In most cases, this is a poor quality friction material. Experienced motorists recommend purchasing pads of the same brand as the discs. This will greatly reduce the risk of grinding noise. Below we will consider other reasons why brakes squeak when braking on a car.
Vibration and grinding of pads
During vehicle operation, especially when driving on uneven roads, the caliper vibrates. And if the rubber bands in the guides dampen these vibrations, then there is no damping element in the shoes themselves. These elements are rigidly attached to the caliper, so the slightest gap provokes unnecessary sounds. Why and where do they come from? The consequence of the fact that the brakes squeak when braking on the car are several factors:
- Generation in the disk itself. Due to long-term operation, its thickness decreases, traces of deformation are formed - beads and notches. The speed of rotation of the brake disc during movement is quite high - because of this, we hear the grinding and vibration that emanate from it when the pads come into contact with it.
- Lack or too thick grease in the caliper guides. Its presence there is simply necessary. If there is no lubricant or it has dried up, the caliper will simply "sour". As a result, the brakes creak on the VAZ car. By the way, when replacing the guides, you cannot use foreign lubricants such as graphite or Litol-24. For this there is a special compound called "caliper guide grease". It is inexpensive (100 rubles for a bag, which is enough for 2 sides), therefore, using other analogs, you will simply earn yourself a problem.
- Incorrect caliper piston stroke. This occurs due to breakdown rubber boot... As a result, dirt gets there, the grease is weathered and dries up. The piston is unable to make the previous stroke. It is difficult to remove dust from it.
- Loose caliper. It is adjusted using a hexagon located on the back of the element.
How do I fix the problem?
If the brake pad whistles, and the problem is not in its quality, this is solved by repairing individual elements. So, the production on the disc is eliminated by the technology of its groove. At the same time, the thickness of the repair layer is respected - a very thin element must only be replaced.
When installing new pads, pay attention to the thin pad - it must be treated with a special paste. Also, if the brake pedal creaks, the place of its contact with metal can be removed by applying lubricant... There are no specific requirements here - even an ordinary WD-40 is used. At reverse installation caliper, diagnose the guides for production.
It is very simple to do this - if there are small "edges" on their surface, and there is a small play in the grooves, this indicates their wear. The problem is solved by the installation It includes anthers, guides, rubber bands, as well as special grease. For VAZ cars, the cost of one repair kit rarely exceeds one thousand rubles. And you can install new anthers and "guides" with rubber bands yourself. The main thing is not to forget to put on an iron plug at the end, which prevents clogging of the guides internals.
Completing the pads with your own hands
To eliminate the squeak, you can round off the parts of the shoe. Often it is its corners that are the source of the grinding sound. Rounding the sides of the pad will provide a softer fit to the disc, respectively, the sound of work will decrease several times.
"Running in" pads
When installing new elements, the initial lapping should be done.
Basically, this gives the same result as we described earlier - rounding off parts of the element. Only in this case you do not need to shoot anything - it is enough to drive a car 400-500 kilometers. The receiving side of the pad will take the desired shape, which will ensure the smooth operation of the brakes.
Wear sensor
This element is installed on many German cars. Oddly enough, but it can also cause brakes grinding. If it was replaced earlier, you should re-check the correctness of the sensor plate attachment.
If it is installed crookedly, in contact with the disc, it emits a characteristic grinding sound.
Moisture and condensation
Experienced motorists have noticed that the grinding of brakes becomes more frequent in rainy weather.
All due to high humidity. After driving through puddles or just in the rain, the slightest drop of water entering the caliper can provoke a characteristic braking sound. A sharp temperature drop occurs. To eliminate this problem, it is enough to press the brake pedal a couple of times - "dry" the system.
Conclusion
So, you found out why the brakes squeak on the car. As you can see, the problem is familiar to many motorists; ways to solve it have been found long ago. In most cases, the squeak can be removed by hand. Well, if it comes naturally, you can't do without good specialist and equipment.
Probably, every driver is familiar with the uncomfortable state that he had to experience when the brakes squeak, especially when dense stream vehicles, in traffic jams, when you have to brake every minute. Let's try to understand in more detail why the brakes squeak when braking, especially if the car has passed Maintenance, and after the car service, the master assured you that it is technically sound.
What is whistling and why?
What if an unpleasant sound occurs? Is it barely audible and doesn't particularly catch your attention? Having received the first signal, it is necessary to understand where the grinding sound comes from, and what it is.
The principle of the brake: the driver presses the pedal, the pressure changes, the pads clamp the brake disc on both sides and stop its rotation. From the moment of clamping until the disc stops, the pads vibrate with a frequency that sometimes coincides in frequency with the frequency perceived by the human ear, and the creak or whistle heard by us also increases in volume, because wheel arch acts as a sound amplifier due to its design. The whistle of the brakes is always present, but its frequency is not always perceived by human hearing organs, so we usually do not hear it.
The main causes and solutions to the problem
Incompatibility of materials. The braking part of the pads (friction) is made of various materials. Each manufacturer has its own optimal combination of braking properties and durability, which is kept secret, because the competition in the market is significant. The higher the stiffness of the material, the more effective the braking properties. At the same time, there is a likelihood of the vibrating effect of a rigid plane, and, as a consequence, the occurrence of a whistle or squeak. The opposite situation arises when using softer materials. The chance of whistling and squeaking is much less, and the part wears out much faster.
In the video - what to do if the brake pads creak:
Consider the following example. After replacing the brake pads, the brakes whistle. Two probable causes that can create a situation like this:
- The material from which the friction part of the pads is made is not compatible with the material from which the brake disc is made. It is recommended to select products from another manufacturer.
- The braking surface of the pad is covered with a protective layer and emits a whistle immediately after installation. It is recommended to drive around such details within two to three days, and then the whistle will disappear.
Design features that reduce the likelihood of squeaking. The metal plates installed between the piston and the shoe to secure it in place serve to close gaps, reducing vibration and therefore reducing the chances of squeaking and whistling. These anti-squeak plates are included in the pads of many renowned manufacturers... If they are missing, you can purchase and install them separately.
The design of the brake shoe can be made with a friction part in the form of one, two or three segments. This has a direct impact on the occurrence of vibration: a smaller area leads to an increase in frequency, respectively, a decrease in whistling or its complete absence.
Brake disk. Uneven wear and disc curvature is one of the causes of squeak disc brakes... The problem can arise when entering a puddle with hot brake discs, with heavy braking, water hammer or overheating of the disc. I would like to note that any pads will emit a rattle on a curved disc, and you can get rid of it only by replacing the old disc with a new one, since the groove of the disc does not always give a positive result.
Other malfunctions. These include all malfunctions that occur during the operation of the car, such as wear of the hub bearing or parts of the brake mechanism, old brake pads that have become unusable. In such cases, not only a whistle may appear, but also a metallic grinding of the disc on the block, on which there is no friction coating. In the event of wear, rattling or rattling noise occurs most often when driving.
Atmospheric impact. Severe frost, high humidity, slush, driving on dirt roads can also cause the appearance of a whistle of brakes. In such cases, it disappears in dry weather. If foreign objects get on the rubbing surfaces, it is enough to remove them or wash the brake mechanism.
What to pay attention to
Front brakes were installed, equipped with a disc system, and rear ones, on which brake drums were installed. Based on the peculiarities of operation, the front pads had to be changed more often than the rear ones. In our time, the situation has not changed.
The device itself of the car's braking system provides for a certain order of operation after pressing the brake pedal. The front brakes are applied first, which forces the front pads to experience maximum load, and therefore to be subjected to more intensive wear. Then the rear ones are included in the work, but they experience much less pressure.
At emergency braking both circuits of the system work simultaneously, but it is the front pads that experience maximum loads and often need to be replaced. It is interesting that it is precisely because of such loads that the previously described problem very often arises - overheating and curvature of the front brake discs... Also, the failure of wheel bearings directly depends on this.
Solving the problem is easy enough
What conclusion should be drawn in order to calmly assess the situation and understand it? It is not at all difficult to get rid of the squeak of the brakes, the main thing is to find out the cause of its occurrence, remember how long ago they replaced the brake pads, replace them if necessary, paying attention to the condition of the brake discs and mechanisms. Enjoy the ride without extraneous squeak and whistle!
Life and health of all participants road traffic, and not only those who are in the car, depend on the correct operation of the parts of the brake system (pads, discs, calipers, hoses and pipes, condition brake fluid).
First of all, consider how often the brakes need to be serviced and checked.
For example, you are an average driver with a fairly relaxed driving style, operating your car, in most cases, in urban conditions. In your case, passing regular maintenance, checking the condition brake mechanisms, hoses and pipes, and brake fluid will be sufficient. You need to follow and follow the recommendations that you will receive as a result of checking your car.
If your driving style is not smooth and calm, then you should undergo MOT twice as often, as such driving leads to rapid wear of the most important parts of the car.
Most frequent check should be if you use the car off-road and off-road. But the problem is this: the working brakes are located very close to the road surface and when driving over rough terrain are susceptible to heavy pollution. In this case, after each such trip, it will be necessary to wash and check the condition of the brakes, otherwise rapid wear or breakdown is inevitable.
What can happen if the wear of the brake system is not noticed in time?
Let's say the brake discs have reached the minimum thickness allowed by the manufacturer. But the brake pads are not completely worn out. Many in such cases decide to ride in order to erase the pads to the end, and only after that replace the worn out parts. This could be done (after all, it is known that brake discs are designed with a significant margin of safety, as a very important part), if not for one BUT: if one part of a pair of disc-pads goes beyond the minimum tolerances, brake cylinder more than the design maximum is advanced in the caliper, because it must provide the necessary pressing force of the brake pads to the disc. This often leads to skewing, seizing and leaking brake actuators. As a result, expensive repairs or replacement of calipers. Hence the conclusion - the miser pays twice.
Brake fluid tends to absorb water from environment(air). This leads to a decrease in the boiling point of the brake fluid (as a result of boiling - airing of the brake system and its complete failure during active braking). In subzero temperatures, it will thicken, which will also greatly affect the effort applied to the brake pedal and braking performance.
Why do new brake pads whistle and squeak?
- Incompatibility of materials... The braking part of the pads (friction) is made of various materials. Each manufacturer has its own optimal combination of braking properties and durability, which is kept secret, because the competition in the market is significant. The higher the stiffness of the material, the more effective the braking properties. At the same time, there is a likelihood of the vibrating effect of a rigid plane, and, as a consequence, the occurrence of a whistle or squeak. The opposite situation arises when using softer materials. The chance of whistling and squeaking is much less, and the part wears out much faster. If the brakes whistle after replacing the brake pads, there are two possible reasons: The material from which the friction part of the pads is made is not compatible with the material from which the brake disc is made. It is recommended to select products from another manufacturer. The braking surface of the pad is covered with a protective layer and emits a whistle immediately after installation. It is recommended to drive around such details within two to three days, and then the whistle will disappear.
- Metal shavings which is an integral part of the material from which the brake lining is made. Usually, chips or threads of light-alloy or soft metals are used: copper, lead, antimony, brass. Metallic inclusions in the pad material remove excess heat from the pad. After all, with constant braking, overheating of parts is possible. If the production technology is violated, and there is more metal in the lining or it does not meet the standards, then a creak is possible during braking. Among other things, such pads can seriously shorten the life of the brake disc.
- Design features that reduce the likelihood of a squeak. The metal plates installed between the piston and the shoe to secure it in place serve to close gaps, reducing vibration and therefore reducing the likelihood of squeaking and whistling. These anti-squeak plates are supplied with pads of many well-known manufacturers. If they are missing, you can purchase and install them separately. The design of the brake shoe can be made with a friction part in the form of one, two or three segments. This has a direct effect on the occurrence of vibration: a smaller area leads to an increase in frequency, respectively, a decrease in whistling or its complete absence.
- Brake disc wear... Disc curvature is one of the reasons disc brakes squeak. The problem can arise when entering a puddle with hot brake discs, with heavy braking, water hammer or overheating of the disc. It should be noted that any pads will make a grinding noise and extraneous noise on a curved disk, and you can get rid of it only by replacing the old disk with a new one, since the groove of the disk does not always give a positive result.
- Other malfunctions... These include all malfunctions that occur during the operation of the car, such as wear of the hub bearing or parts of the brake mechanism, old brake pads that have become unusable. In such cases, not only a whistle may appear, but also a metallic grinding of the disc on the block, on which there is no friction coating. In the event of wear, rattling or rattling noise occurs most often when driving.
- Atmospheric impact... Severe frost, high humidity, slush, driving on unpaved roads can also cause the appearance of the brake whistle. In such cases, it disappears in dry weather. If foreign objects get on the rubbing surfaces, it is enough to remove them or wash the brake mechanism.
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Novice motorists often ask the question: how does the creak or hum of the brakes appear when braking. According to experts, this whistle appears when heavy wear brake pads. In case of working out their operational life, they need to be urgently replaced. But what if the brake pads squeak on a newly purchased model car? Let's try to understand this issue.
The principle of the brake system of the machine
All modern models of braking systems work according to the same type. The work takes place in several stages:
- When the brake pedal is pressed in the hydraulic brake system pressure begins to rise gradually;
- The increased pressure in turn causes pressure in the brake pads;
- The pads, in turn, transfer energy to the body of the wheel disc, which already brakes the car on the road.
Thus, the pressure from the driver is transmitted to the caliper, which is inextricably linked to the disc. As a result, the force applied to the brakes is directly proportional to the pressure of the disc on the wheels. That is why drivers can control the braking speed with a slight movement of their foot.
At the same time, the manufacturers of brake pads and discs have made sure that your vehicle runs quietly at all times. Recall: when the brake system is turned on, the disc is pressed against the base of the wheel, causing vibration. To eliminate noise during touching and to prevent strong vibration of the wheel, manufacturers divide the area of the brake pads into several specific segments, each of which has a special cut along the surface. This also suppresses the occurrence of vibration squeak.
Often, when buying brake pads, buyers overlook the fact that there are no slots, which can cause not only the squeal of the pads even on a new car model, but also the appearance of a knock in the front suspension on small bumps. However, you can make slots in the pads with your own hands. To do this, stick to following parameters slots:
- the width of the cut should be no more than 2 mm;
- the depth of the cut is 3.5-4 mm.
Advice: If you want to completely dampen the vibration of the wheels when braking, round off the new brake pads. To carry out this operation, contact a car service, where they will slightly file the edges on the pads and install new brakes to replace the old ones.
However, the reason for the squeak in the brake system is rarely associated with the absence of slots. We offer to consider the most common problems with brakes and effective methods their elimination.
Detecting material incompatibilities after purchasing pads and discs
Here the problem is related to the fact that each of the manufacturers keeps in secret the composition from which the friction (or, in other words, the braking) part of the pad surface will be made. As a result, due to the mismatch of the material, a squeal occurs when the pads and disc come into contact. As manufacturers are constantly looking for a way to create the most economical pads that combine high braking performance and guarantee durability, factories cannot come up with one patented formula.
The harder the material eventually comes out, from which the frictional component of the brake pads will be carried out in the future, the more effective the braking will be. At the same time, harsh compounds will cause strong vibrations in the wheel and a sharp creak. On softer pads, the likelihood of squealing brakes is reduced to a minimum, but their wear is much faster.
If the material of the set of friction linings and brake discs installed on the machine is incompatible, a squeak will appear. Moreover, it is audible even when driving on a straight road without applying the brake. To solve this problem, simply replace the brake pads on models that are made by another manufacturer.
Advice: on "curves" and worn out brake discs any set of pads will creak.
Samples of discs are bent as a result of overheating of the structure or during a water hammer (deep hole, puddle) on strongly heated discs during braking. Here you can only be helped by balancing the brake discs (in the common people it is called a groove), and in extreme cases - replacing all wheel discs with new samples.
Exactly the same should be done when a worn out wheel bearing is found.
All of the above problems can be joined by the appearance of noise due to wear of one of the parts of the brake mechanisms:
- Brake caliper guides;
- Piston;
- Racks and other accessories.
In such situations, vibration, accompanied by whistling and grinding, will appear even during normal movement. vehicle on a straight road, and especially strongly when cornering, even in the absence of braking.
For repair, dismantle the spare part, clean it well and lubricate it. In case of severe wear, replace the caliper and pistons with new samples.
Advice: if, when braking, together with a whistle, the car stalls on the move, then you should computer diagnostics brake and running systems of the machine.
Whistling due to weather conditions
Experienced drivers have noticed that with an increase in humidity indicators relative to average, together with a decrease in temperature, the likelihood of hearing a whistle in the brake system is much higher than under the same conditions, but in dry sunny weather. This is due to the fact that the material from which the friction parts of the brake pads are made takes on different characteristics under conditions of changing temperature and relative humidity.
If the car starts whistling exactly when the weather changes, then you can be sure that the whistle will disappear under normal weather conditions or after a certain number of intensive braking by the vehicle.
Advice: the hall sensor on the VAZ-2109 can also give incorrect values in bad weather. If both of these factors converge on the same day, then replacement of the brake system is not required.
Also, the whistle appears when sand, dirt and dust get into the "grooves" of the pads and discs of the machine. A strong whistle can cause foreign objects and parts of the brakes to enter, which were formed during the erasing of the braking sectors. The solution to the problem suggests itself: clean and rinse all components of the brake mechanisms, and if any foreign objects are found, carefully remove them.
The above list of actions should save you from the further appearance of squeaks, whistles and squeals of the brake system. However, if only a temporary solution to the problem appears, just contact the nearest car service, where you will be offered to carry out a full diagnosis of all components of the brake system and identify the malfunction.
Remember:
- It is necessary to replace old pads with new samples after every 75-100 thousand km of vehicle run.
- Buy brake pads and discs of the same make and type as the original ones on your car.
- When driving on wet road Squeaking in the brakes is not uncommon, so dry the brakes a little beforehand.
- To check the health of the pads, carry out about 5-10 gradual braking at low speeds.
- Any set of new spare parts, including the brake system, needs a certain amount of time for grinding.
