One of the most unpleasant effects indicating a malfunction of the car braking system is the beating of the brake pedal. This cannot be said to be a fatal defect, but in a real traffic situation it can negatively affect traffic safety. The beating of the brake pedal is manifested in the fact that while the car is braking, the driver feels the pedal begin to vibrate, and the greater the pressing force, the more powerful the vibrations. What are the reasons for this effect, and can it be eliminated? We will examine these questions in this article.
Completion of work
Our experiment ended successfully, and the hubs have been time-tested - over the last year I have been driving without any beats. It’s just that the “ten-man”, asking a question about the beating of my steering wheel during high-speed braking, reminds me of a long-forgotten problem. Of course, sooner or later the brake discs will have to be changed by purchasing completely new ones, but this is a completely different story, since the whole problem will lie only in their choice.
Could the hub be faulty? Of course it can. Once, while repairing my car, I was very surprised by one circumstance. A slight runout of the hub can lead to quite noticeable runout of the brake disc. This is especially true for places that are as far away from the axle as possible, that is, for brake pads. In the case of high-speed braking, the brake pads strongly compress the disc rotating at high speed with the presence of irregularities, which leads to vibrations that are transmitted to the steering wheel through the tie rods, the steering lever and the steering mechanism itself.
Steering wheel beating
is one of the most irritating and unpleasant factors when operating a car. In addition, it can not only infuriate any driver, but also in some cases, it becomes the cause of an emergency situation.
Vibration on the steering wheel
can be of two types:
- Vibration at speed;
- Vibration when braking.
The sources of occurrence of these two types of vibration are different, as is its very nature.
The problem associated with vibration of the steering wheel at speed (or while driving) quite often appears among car owners after, as well as as a result of hitting a hole at speed. Moreover, the runout can be either constant or occurring at a certain speed (mostly from 80 km to 100 km/h), although there are cases when the runout cannot be analyzed when it begins at different speeds and different road surfaces.
You can guess for a long time what the problem is, but one thing is clear, in most cases it is an imbalance in the mass of one or several wheels
. Let's consider these and other reasons, which, as a rule, also complement each other.
Suspension and wheels
Approximately the same result is obtained by wear of some components of the suspension.
Silent blocks, ball joints, and support bearings that have exhausted their service life will cause the wheel to develop lateral play, which will be the source of the problem.
It should be noted here that an additional sign of wear on the suspension components is knocking noises when driving over uneven surfaces.
It’s not difficult to check the condition of the suspension; just swing the levers with a mount, and if the silent blocks and ball joint are worn out, this will be immediately noticeable during the check. But before that, check whether the disk is screwed on well; loosening at least one of the bolts can lead to vibration of the entire car.
Although rare, vibration is caused by the hub and its bearing. As a result of severe wear of the bearing seat, play appears in this unit, which will be manifested by impacts on the steering wheel.
The wheels may also hit the steering wheel when braking, so you need to check:
- Damage or imbalance of the disk;
- Loose bolts (usually happens when a car is “re-shoeed.” The bolts are simply forgotten to be tightened);
- Tire defects;
- Violation of camber/toe angles.
As you can see, there are two main causes of the problem: play in the chassis and damage to the brake system elements.
That is, the brake discs, due to overheating, the suspension and steering mechanism have not been serviced for a long time, new wheels are installed on the car, which have not been balanced and as a result the driver receives quite unpleasant and dangerous consequences.
Vibrations sent into the steering wheel after changing the disc, hub or bearing
If you notice that vibrations reverberating through the steering wheel or body of the car were detected after work was carried out in a car repair shop, then you need to look for the cause of this misfortune there. Such shaking could be caused by a previous change of the brake disc (as well as the hub bearing or the entire hub), which from time to time causes the steering wheel to shake. Usually this happens due to low-quality replacement elements, although coupled with this is an irresponsible attitude towards the procedure for replacing parts. The disk could have been tightened with the wrong force, or the disk could have been installed crosswise without tightening. The torque that should be applied to tighten is often indicated directly on the disc.
If runout on the steering wheel or body of the car was detected after operations on the chassis of the car, try to involve the same specialist who performed these operations on the chassis.
Where to look for problems?
It is noteworthy that it can hit the steering wheel when braking on any car - VAZ-2108, Priora, Kalina, Ford Focus 2, Mitsubishi Lancer 9 and others.
No matter what vehicle this phenomenon occurs on, the malfunction must be eliminated urgently, and its sources must be looked for in:
- brake system (disc and calipers);
- steering;
- suspension;
- wheels.
Often car owners have to completely go through the above mentioned elements of the car in order to fix the problem.
The appearance of beating in the steering wheel during braking can occur for various reasons, for example, wear or damage to the components of the chassis, for example, a bent disk.
Reasons beyond the automatic transmission
Quite often, vibration that appears to be coming from the automatic transmission is not. Vibrations from the engine can be transmitted to the body (and box) if its mountings have become unusable. For example, if there is vibration in the automatic transmission when you engage a gear, this may indicate the engine mounts (but also wear/displacement of the automatic transmission mount).
Another common reason is poor quality fuel. If you pour low-quality gasoline into a modern injection engine, it can quickly clog one or more injectors, as a result - the engine begins to “tweak”, and engine vibration will appear when the automatic transmission is engaged. In this case, vibration when accelerating may disappear because the pressure in the fuel line increases. The fuel filter becomes clogged, with a similar effect.
Similar manifestations are caused by faulty ignition coils, spark plugs or armored wires: the fuel combustion cycle is disrupted, the engine sneezes and troits. A characteristic symptom is a drop in speed and shaking when switching to mode D, vibration when engaging the reverse gear of the automatic transmission from idle. The engine does not have enough power, and it begins to “shudder” noticeably, transmitting the impulse to the body and gearbox.
The next probable cause is a malfunction of the idle speed control (if vibration occurs during idle operation). The corresponding spare part must be replaced. Similar symptoms occur if the lambda probe breaks down.
Beating may occur due to a dirty throttle valve; the problem can be eliminated by cleaning it.
A large number of malfunctions leading to vibration are problems of the chassis. For example, wear on constant velocity joints of drives (commonly abbreviated as CV joints) causes vibration when the car is loaded, during acceleration. With this malfunction, the symptom may disappear when the driver, having completed the acceleration phase, releases the accelerator pedal. Some car owners note that the malfunction is not detected by conventional methods; upon visual inspection, the spare parts appear to be in good condition, and the problem only appears under load.
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Vibration from unbalanced or poorly placed wheels (especially the front axle) can also “give” into the box. The driver, in addition to unpleasant vibrating sensations, will feel the car “walking” along the highway, pulling it in different directions, and deteriorating control.
There may be other problems with the chassis, reflected by vibration of the box.
Vibrations in the steering wheel/brake pedal
Cause: worn or deformed brake discs.
The brake rotor (disc) is part of the braking system; it rotates together with the wheel. Let us remind you that the wheel is fixed directly to the disk. By pressing the brake pedal, you force the brake pads to press against the brake disc, as a result, the rotation of the discs (and wheels) slows down and the car stops. As you understand, the brake disc is very important for the operation of the car.
Let's try to look at how brake discs work. Almost always discs are made of metal. They are made to a special width, which depends on the manufacturer and model of the machine. When you press the pedal, the pads, on which the abrasive material is applied, rub against the disc, creating serious pressure - the disc ultimately experiences a strong increase in temperature. This, in turn, leads to minor, but still changes in the metal (density changes) - the disk must be cooled over the entire area.
In practice, such cooling does not always occur (and sometimes abruptly), as a result of which a change in density leads to deformation changes only in some places, and the nature of the deformation itself is visible as a wavy surface. Next, this is what happens - if at high speed the pads are pressed against such a deformed disc, then the entire brake caliper begins to tremble, transmitting this vibration to the wheel, which, in turn, sends a beating either to the steering wheel or to the body of the entire car.
A sharp drop in brake disc temperature after pressing the brake pedal for a long time can be caused, for example, by snow or running into a puddle.
The common people often hear the phrase “disc led” - it just means the deformed surface of the brake disc. An additional sign, coupled with vibration, indicating deformation of the disk surface is a bluish tint of the metal on the disk, which is also a consequence of overheating.
It is very easy to diagnose a disk for deformation. You will need to jack up the wheel. In this case, the handbrake must be removed, the gear must be put in neutral (make sure that the car does not roll away). Then, in this state, spin the wheel - rotation should be easy and without jamming. An abnormally fast stop of the wheel or “heavy” rotation at a certain point most likely indicates damage to the brake disc.
If it is the disc in front that has a deformed surface, you will feel a beating that radiates directly to the steering wheel. If the rear disc is to blame, then vibrations, in principle, may not be felt (except for severe deformation of the disc; in this case, at high speeds, shaking during braking is still felt). The vibration felt in the brake pedal does not clearly indicate whether the disc is warped at the front or rear.
If you drove down a hill for a long time using the brake pedal, and then drove into a puddle on the road, then the disc, instantly cooling, may well be the cause of the deformation. But deformation is not always caused by sudden cooling. On the contrary, excessive overheating of the disk can also cause deformation. In this case, the brake pads continuously rub against the disc, preventing it from rotating and causing a strong increase in temperature. As a result, the brake caliper jams. To eliminate this effect, you will need to remove the cause of the heating.
If the car is equipped with brake drums, then deformation on them is rare.
The most popular reason is bent brake discs.
The braking disc or rotor is driven in tandem with the wheel. This structure is clamped together with the pads while reducing the speed of the car mechanically. If this system is faulty, then driving the car is unsafe. Brake discs are one of the key parts of a vehicle.
Why is there a load on the steering wheel if the shape of the brake disc is damaged? To do this, you need to understand how this design works. The part is made of metal and can have different widths. When you press the pedal, the pads mechanically press on the disc from both sides. The structure is subjected to enormous load and its temperature rises. Due to temperature changes, the state of the metal changes and over time there is a gradual change in shape.
The disc takes on a “wavy” shape and this causes vibration in the steering wheel, the entire caliper and even the car. So, we have identified the first reason why the steering wheel shakes - you should remove the wheel and check the brake disc. The main sign of a change in shape is the appearance of a bluish tint. You can jack up the car so that the wheel spins freely and see how the whole structure moves. You can also brake with the handbrake - if the steering wheel shakes, then the problem is clear.
It is useless to level the surface - it is much easier to replace the entire structure. However, it is quite expensive - at least 10 thousand rubles. Some craftsmen may suggest boring it out, which is a budget option to fix the problem. The waves are simply ground down until the surface is completely flat.
Ways to solve the problem
Whatever the reasons for the steering wheel beating, it is necessary to carry out high-quality diagnostics and eliminate the problems. This will make it possible to avoid expensive repairs, and most importantly, prevent accidents!
If the steering wheel shakes at low speed, proceed as follows:
- check the cleanliness of the wheel rims;
- check the balancing and fastening of bolts on the wheels;
- test discs for deformation;
- check the quality of rubber;
- diagnose the suspension;
- examine brake discs and drums;
- check the engine mounting;
- try the quality of the drive shaft.
Wheel rims are easier and faster to clean at a car wash. A stream of water will remove accumulated dirt. Hit the disc with some object, reducing the amplitude of vibrations of the steering wheel, in order to safely drive to the car wash or service station.
Have your balancing done at a tire shop. Balance all 4 wheels, especially if the steering wheel shakes at low speeds. At the same time, eliminate the deformation of the wheel rims and give them their initial shape on a straightening machine.
Replace defective tires. It will not be possible to restore it - you will have to buy new tires and mount them according to the canons of proper balancing.
The beating that occurs during braking can be eliminated at a service station. The machine grinds and restores the surface of the brake discs if the degree of wear is low.
It is better not to fix steering wheel wobble at speed yourself. Only car services will accurately determine the cause of the breakdown and eliminate it. Most workshops work with specific brands of cars; they have a better understanding of the specifics of the models, know the characteristic “sores” and are able to quickly recognize them.
Unfortunately, most car owners believe that car vibration and steering wheel wobble necessarily mean that they simply need to balance their car's wheels. But this is not always the case, although improper wheel balancing is one of the most common causes of such vibration on the steering wheel or the entire car.
The problem is that vibration of the steering wheel (as well as the entire car) is not only one of the most common, but also one of the most annoying problems. Moreover, it often creeps up on us gradually and unnoticed - until one fine day we begin to understand that the steering wheel is already hitting quite hard at speed or when braking, and it reverberates throughout the whole car, but we understand that we are already accustomed to it and That’s why we don’t rush to a specialized service or tire shop to fix the problem.
But, most likely, at this time you asked yourself the question, what does it mean if your car vibrates, what are the reasons for the steering wheel beating? And, despite the fact that there are a number of reasons for this, it will most likely be possible to sort out the problem without resorting to large expenditures of money. However, having established the cause of the beating, you may have to spend money on repairs and eliminating the causes of such vibration. We must also understand that in the long term this will give us significant savings due to the failure of certain steering or suspension elements.
To determine the cause, we first need to determine the specific conditions of vibration - drive along the highway (the more deserted it is, the better) at different speeds and feel the beat and measure at what speeds it starts and at what speeds it disappears (most often you will notice , that there are two ranges of occurrence of the beat: first at low or medium speed, then the vibration disappears at a higher speed, and then its reappearance at an even higher speed; however, if the vibration is very weak, then it can only be felt in one range - at high speeds). In addition, determine how the car behaves during acceleration and braking - vibration disappears or increases depending on acceleration at different speeds.
So, let's look at all the reasons why vibration appears throughout the car and the steering wheel hits:
Diagnostics
Checking brake discs with a micrometer;
So, we have looked at the probable causes of the brake pedal beating. How can we determine which of them played a negative role in this particular machine? This requires a comprehensive and thorough diagnosis. And it is best if the research is carried out in a specialized car service center.
As part of diagnostic activities, the following work is performed:
- checking the geometry of discs and drums;
- checking the pads;
- testing of wheel bearings;
- inspection of suspension fasteners.
The geometry of discs and drums is checked on a special stand, which accurately records the curvature of the flat pressure pad of the disc and the ellipticity of the inner surface of the drum. To determine the degree of pad wear, use a caliper or micrometer. The condition of the wheel bearings is determined using special equipment that determines the amount of camber and toe-in of the rotating wheels from the normal position.
How to avoid car brakes from squealing
If the brake pedal begins to vibrate when pressed, then this problem will not go away on its own. It is necessary to diagnose the machine as soon as possible and eliminate the malfunction. To avoid such troubles in the future, you need to follow these recommendations:
- Monitor the brake fluid level in the reservoir;
- Regularly check the brake system for leaks;
- Change the pads on time, without waiting for their maximum wear.
The braking system is nothing to joke about, and at the first symptoms of its malfunction, the problem should be eliminated.
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Pads as the reason for the steering wheel beating
Although the market is saturated with counterfeit and low-quality pads, they, along with high-quality but worn pads, are not able to cause beating in the steering wheel or car body when you press the brake pedal. This is explained by the fact that this spare part does not move on its own and is loaded from time to time, and not constantly.
Additional factors causing vibration that occur infrequently:
- problems with the steering rack or significant wear of the ball elements in the chassis;
- problems with the racks (in this case, the beating is mainly felt when performing a turning maneuver in the direction opposite to where the rack is installed);
- shock absorber supports that have failed due to damage or wear;
- significant physical impacts (curb, accidents, etc.). Note that, as a rule, before the disc deforms, there is damage to the wheel rim;
- breakage of steering tips.
Steering
Here, the steering wheel may hit the steering wheel when braking due to worn or misadjusted steering elements.
At the same time, many believe that if there is play in the steering, the beating will be constant while driving, but we are considering the occurrence of impacts only when braking.
But this is not entirely true, and in order to understand how wear of the steering mechanism can affect the processes occurring when a car is braking, we should consider the theory a little.
The wheel always moves along the path of least resistance, and the higher the speed, the more difficult it is for it to change its trajectory.
Causes of vibration when braking
Worn, rusty, dirty or weakened brake pads cannot effectively grip the surface of the brake rotor. Pads can also become contaminated with oil, brake fluid, dirt, road salt or even grease due to careless installation.
Any of these reasons can cause the steering wheel to shake when braking.
Please note: Although there are ways to clean dirty brake pads, it is best to replace them
Dry, corroded, defective, missing brake caliper fasteners (especially the caliper guide pins, which prevent the caliper from running smoothly and smoothly) will cause the brake caliper to seize and bend, meaning it will not be able to press the pads straight to the surface of the brake rotor.
Also, the above reasons may incorrectly press the pads against the rotors, which can lead to their overheating, causing them to vibrate during braking. Brake pads operating with a faulty caliper may wear faster and unevenly.
You can replace the pads yourself, but properly cleaning and lubricating rusty caliper guide pins is a job best left to the professionals.
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What to do if the brake pedal hits
Methods for eliminating the effect of brake pedal beating are obvious. This is a reduction to normal of all components, due to the malfunction of which it occurs. The simplest and often the only possible way is to replace the worn part with a new one. When discs or drums wear out, you need to buy new ones and install them in place of the old ones. However, the design features of these elements make it possible to avoid such a costly option.
The fact is that both discs and drums are made with some margin in thickness. Therefore, they can be processed (turned) on a metalworking machine, eliminating the curvature of the flat surface of the disks and the ellipticality of the drums. Just keep in mind that this method can only be used once. After one groove there will be no reserve in thickness left - the disk or drum will become so thin that it will bend even with relatively little heating. For drivers who practice an active driving style, it is generally not recommended to use machined discs and drums.
How to determine “your” reason
The simplest solution to the problem is to have the vehicle serviced. But, in this case, there is no guarantee of the speed and quality of such work. They can also do unnecessary repair work, for example, completely replacing the steering mechanism. Few car mechanics would want to dig around and look for the real causes of the malfunction. To prevent this from happening, any car owner needs to at least approximately know the source of why the steering wheel may be shaking.
Based on this, I advise you to take the path of minimal financial costs and try to find out on your own, without using expensive equipment, why the steering wheel shakes when braking. To establish the root cause of steering wheel vibration, you first need to establish how the car behaves during acceleration and braking - the vibration disappears or increases depending on movement at different speeds.
The source of vibration or beating on the steering wheel can be deformation of the brake drums or discs. In this case, their working base should be ribbed, wavy, knobby and not perfectly round. This can happen due to severe wear or due to overheating during a long and sharp press on the brake, rapid, long braking and overheating, and then sudden cooling, for example, after getting into a puddle. Ultimately, the brake disc takes on a slight wave-like shape, and the drum simply loses its perfectly round shape.
As a result of overheating, the disc often turns bluish. When brake pads make contact, they compress the drum or disc, causing the entire rotating braking system to vibrate. In this option, a complete replacement of such a mechanism is necessary.
Pay attention to the tie rod ends - there should be no play in them. To check, first lift the vehicle with a jack, ask someone to hold the steering wheel, and tug on the steering rods yourself from different sides.
If there is no play, check the steering rack, as its wear can also cause the steering wheel to shake when braking.
To check, you need to jack up the car and place the ball joint on a stable support so that the wheel is completely in the air. Then grab the top of the wheel with one palm, and the bottom part with the other, and try to loosen the wheel, pulling it in different directions in turn. If you observe wobbling, then I can say with confidence that the ball joint on your car is worn out and urgently needs replacement.
It is possible that the reason for the beating of your car’s steering wheel is hidden in imbalanced balancing. If dirt or snow gets into the disc, then over time a beating is felt, which disappears immediately after gaining speed or after a few minutes of movement. This reason can be easily confirmed or refuted; a visual inspection is necessary.
Check whether the wheel nuts and bolts on the vehicle are loose. The problem is easy to fix and easy to diagnose. This source of beating is obvious and, it is worth noting, the most dangerous. If this reason is not established in a timely manner, then in a situation where you sharply press the brake pedal, the wheel may completely fall off the car. To do this, slowly stop the mechanism and simply tighten all the wheel fastenings.
I recommend inspecting the wheel nuts after visiting a tire shop. Most often, tires and wheels are not ideal. Due to their defects, the centrifugal force changes during wheel movement. The point at which its weight is greater will drag the center of the wheel towards itself when the pedal is pressed. Such tension will pass through the chain of rods, which will ultimately end up on the steering wheel in the form of rattling.
Remember that it is necessary to balance not only the front wheels, but also all four wheels. It’s good that in the modern world it’s easy to find the information you need with a simple set of words in an Internet search engine. But if you were unable to find out on your own why the steering wheel shakes when you brake, then I advise you to seek the help of specialists.
