What to do if the calipers knock?
No matter how good is the sound insulation, the rattle from the calipers will be clearly noticeable. This problem is faced by many motorists. What is noteworthy, the knock occurs only on small bumps. On smooth asphalt and at high speed, there are no extraneous sounds. If you heard a characteristic ringing in the front suspension, check the condition of the brake elements. Rattling calipers may be the cause. What to do in this situation? The answer to this question see further in our article.
Looking for the root of the problem
So, what causes such a characteristic ringing? The reason lies in the insufficient pressure of the pads to the discs. As a result, there is a gap between them. Pads vibrate on a bump and unintentionally touch the disc surface.
This causes the intrusive sound. What is remarkable, from the street side it is more similar to ringing. And inside, muffled thumps are felt. Sometimes it indicates malfunctions with shock absorbers or ball bearing. But you don’t want to rush into action and overhaul the suspension. Probably you just have a rattling brake calipers.
Rattling caliper – what to do: how to eliminate rattling with your own hands
Hello all! Hardly anyone will argue with the fact that the proper operation of the braking system is the key to the safety of every driver. So today we will continue this topic, and talk about why the rattle caliper, what to do in this situation and who is the instigator of noise.
Surely everyone knows that you should always keep an eye on the degree of wear on your brake discs. We also talked to you about the brake drums shaping, and also studied the nuances of self-shaping brake discs. I do not urge to do it with their own hands, but the features and objectives of such procedures you must know.
The caliper refers to the brake system of the vehicle. He comes as a front and rear. But in both cases, its treatment is performed approximately according to the same scheme. Yes, and the causes of knocks are identical.
Plate
Many manufacturers install special antiskrip plates from the factory. They follow the contours of the pad and are up to one millimeter thick. Many do not see the point in installing these elements. But there is an effect from them. If the spring is not able to press the pads properly, this plate partially compensates for this gap. If the calipers rattle, what to do? You need to inspect the brake mechanism and check the presence of the anti-squeaking plate.
Pay attention! Even on a fully serviceable car should provide a small gap between the working surface of the disc and the friction material of the pad. But it is so insignificant that the sound from the contact of the parts is not reproduced. If, however, the brake components are heavily worn, you should not place several plates at a time. This can impair the braking system, and you will be disappointed in the effect.
Guides
The caliper is under quite a lot of stress all the time. Therefore, a problem with them is not uncommon. And on some models of Chevrolet, it is a generic disease, appearing already after 20,000-30,000 kilometers. There are several ways to fix the problem:
Revision of the calipers.
In 40 percent of cases, the front caliper rattles due to dry lubrication. Many car owners are unaware that this part needs periodic maintenance. How often should it be done? Specialists give the answer – lubrication is performed at each replacement of the pads. The resource of the latter can be from 20 to 60 thousand kilometers, depending on the location (front or rear), as well as the driving manners of the driver.
How to perform a revision? First, you need to find a quality lubricant. It should be specialized – just for the guides. Reviews do not recommend using grease for hubs, as well as copper and ceramic counterparts. They dry out quickly and are not suitable for use in this place. A popular manufacturer of specialized grease for calipers is Liqui Moli. This product is usually sold in vacuum bags. One is enough for two guides. The grease does not lose its properties at temperatures up to 200 degrees Celsius.
After purchasing the material, you can get to work. So, first, using a wheel wrench, you tear off the wheel bolts. Then you set the jack and lift the part of the body up. Remove the wheel completely and proceed to the calipers themselves. There are two “14” bolts on the back side of it.
We unscrew them with a screwdriver or a ring spanner. We also inspect the condition of the dusters. If they are damaged, new grease will not help to solve the problem. It is put only if the caliper guide dusters are sealed. The seat and guide pin should be cleaned beforehand. Then squeeze the grease from the bag on the surface. Then the element is assembled in reverse order.
Note! If the piston duster is damaged, it must be replaced immediately. Otherwise rattle the rear calipers and front will constantly.
The same work must be done on the adjacent brake mechanism. In order not to run to the store when you find a damaged duster, it is recommended to buy a repair kit in advance (in a pinch it will remain “in reserve”).
Causes of knocking in brakes
The main reason for the rattle calipers is not the roughness of the domestic roads. As a result of high mileage or untimely maintenance the holes under the guides are broken. At least once a year is recommended to check the presence of oil in them, as well as the wear of the rubber anthers.
The main reasons for this phenomenon are several:
- Poor fastening of the caliper itself;
- premature wear of the guides;
- Heavy wear of the brake pads.
Diagnosis is better to start with a check of the state of the pads. To do this, you can assess the degree of their wear while driving. The car begins to brake worse, increased force is required when pressing the pedal. Typical squeaks and pedal bouncing also indicate that the pads should be replaced. Experienced drivers can even tell by eye the degree of abrasion.
Installing the spring on the brake caliper
The frequency of pad replacement may be different on different brands of cars, most often it is made every 10-15 thousand kilometers of mileage. The knocking of the pads on the bumps does in fact somewhat resemble a similar thundering of the calipers. A full bump can cause the brake disc to wear out or even cause the brake cylinder to squeeze out.
Guides are also an important part of the system. In practice, it is often a question of wearing out the sockets in which they fit. In the first case, you have to go to the store for a new set. In the second, experienced motorists suggest resorting to special rubber bands, with which you can solve the problem quickly and on a budget. Such rubber bands are put on the pins of the guides – this allows you to get rid of extraneous noise.
In some cases, it is possible to fix the situation with the lubrication of the guides. For this purpose, it is removed from the seat and thickly processed. For a certain time, this method helps to solve the problem. For inexpensive car brands in the old way drill additional holes in the brake block and caliper – through them make a clamping spacer spring.
Bad fasteners of the caliper actually not so often acts as the culprit of the situation. Fasteners unscrewed when driving on dirt and just roads with poor road surface. Another option – the service station employee badly fastened it during the repair or diagnosis of the brake system. In such cases, quality tightening of bolts and nuts is enough to get rid of knocks.
What to do if the pads in the caliper rattle immediately after replacement?
In such a case, the culprit of the problem is too thin a disc. Usually its service life is from 120 to 200 thousand kilometers. With a significant depreciation, neither lubrication nor additional plates will help to return the previous gap. Exit from a situation only one – replacement of a brake disk on a new.
Some people perform the turning of this element. But it is worth remembering that this operation is done only if the part is thick enough. In our case, this operation can also harm.
If the calipers rattle, what to do? If you install a new disc and pads, the problem should resolve. But if it remains, you can try to replace the clip.
Also turning the holes for the repair guides helps to solve the problem. Pay attention – in this case you should choose larger guides. Otherwise all the work will be done in vain.
How to determine if calipers are knocking
Knocking calipers is a common problem for many cars, and in some car models it can be called a “generic disease”. For example, in a number of Chevrolet vehicles, the calipers start knocking before 30,000 kilometers of mileage, and this malfunction is related to the guides.
Determining that the calipers are knocking is simple enough. The best way to hear the knocking of the caliper is when the car is moving at low speed, and especially when passing obstacles. That is, to hear it, it is recommended to listen to the workings of the car’s suspension when driving over a “lying policeman” or when driving on a dirt road. When you press the brake, the knock disappears.
Read also: What is gravitex and how to apply it to individual parts of your car? Answers and recommendations.
It’s worth noting that in most cases, knocking calipers is not a problem covered by the car manufacturer’s warranty. Accordingly, the driver has to solve the problem for a fee at a service center or on their own.
Is the caliper really knocking
In fact, there are many elements in the car that can knock. These are the same engine valves and the notorious hydro-compensators, about the knocking of which we have already talked recently. But also knock calipers. And this phenomenon is widespread enough.
For some machines, such symptoms are quite common and their appearance is purely a matter of time.
The first thing to do is to determine if the calipers are really knocking. Fortunately, it is not necessary to go to a car service and spend money on expensive diagnostics. You may do it yourself. Knocks are most evident, when a car moves at low speed. It is worth to intentionally pass through light obstacles. The simplest variant is to run over the lying policeman or to drive out on the ground. And should you press the brake, the knock will disappear.
One of disadvantages of the considered malfunction is the fact that it is not covered by warranty. Roughly speaking, if the car is under warranty, you will have to do caliper repair at your own expense.
Wear guides and bushings
When the guides and bushings are worn, the knocking occurs when braking, as well as on uneven pavement. In the most advanced cases, the pads rattle throughout the entire drive. To solve the problem, you need to buy a special repair kit. It includes 2 dust pads, 2 guides, 2 bushings and a special lubricant.
Instructions on how to eliminate the knocking of the pads due to the guides are given below.
How to get rid of a knocking brake calipers
A knock coming from the front of the car when passing a bump is not always an indication of suspension problems. The knocking can also parts of the brake system, in particular the caliper. And such knocking sooner or later overtakes any car. Today the editorial staff of Autobann.su tells about the ways to eliminate this acoustic defect.
The nature of the origin of the defect
Caliper knock comes from the loose fit of the guides in the sockets of the brake caliper. A loose clearance allows the caliper to move relative to the bracket, which causes a knock. It is acceptable for the malfunction to occur after an impressive mileage run, as a result of natural wear of the seats for the guide pins.
Other manifestations are considered deviations from the norm. This can be caused by both a factory defect and untimely maintenance of the guides. Yes, poor design of brake caliper mounts is quite common on modern cars. One example is the front-wheel drive Lada Vesta with rattling calipers.
How to be sure that the calipers knock
The knocking of the brake caliper has a special character, identifiable at once in cases of repeated manifestation of the defect. If the problem is diagnosed for the first time, it is appropriate to use one of the ways:
- Drive over a bumpy road. Take a route on a road of unimportant quality, and at the appearance of a knock immediately press the brake pedal lightly. Repeat several times. If the sound immediately goes away after pressing the brake pedal, the calipers are the problem.
- Wiggle the caliper to the sides. It is not necessary to remove the wheel. It is enough to turn the steering wheel all the way out and jiggle the caliper from side to side. An acoustic defect is instantly detected.
How to get rid of the tapping of the brake caliper
What do motorists who encounter such a problem for the first time usually do? The first thing owners resort to treating the guides. On what to lubricate the guides calipers, we dealt in the previous material. From the same place we learned the main reason for this procedure – to prevent jamming of the caliper.
For the defect in question, lubrication should be regarded as a preventive measure, but not as a way to cure it. This is confirmed by the experience of drivers who have tried the lubricant treatment of the guides as a method of treating the caliper from knocking. 1,500-2,000 km and the part rattles again. It is the same as the treatment of guides with the grease, intended for struggle against brake squeaking – the beneficial effect is zero.
How do the motorists reason further, being disappointed in curative properties of the grease? In general, there are two directions:
- To work with a pair “a finger-blade” with the purpose of reduction of a gap between details. There may be several solutions – from replacement of the bracket with a new one to installation of heat-resistant rubber rings between the guide and the hole in the bracket.
- Fix the caliper relative to the bracket. The solution is not quite successful, but it is actively practiced in the automotive environment. The caliper is fixed with springs of various designs and plastic couplers. Install the pads with a rubberized coating on the non-working side.
Working with the guides
The rational solution would be to replace the pins with new ones. In reality, however, this activity is of little use: the holes in the bracket are already broken and the new guides will also dangle. If you consider the idea in a slightly different way, the effect will be evident. What exactly needs to be done?
In fact, you need new pins, but they need to be custom-machined to fit the actual geometry of the existing socket in the bracket. It is almost impossible to find such a part on the market, but an experienced turner will be able to cope with the task at once. After restoring the tight fit, the knocking will disappear at once.
But increasing the diameter of the guide using various methods is not a good idea. Various mechanical engineering techniques (surfacing, spraying) are rarely practiced due to the unprofitability of such an approach in private business. In other words, it is easier to grind out a new finger than to try to reanimate the old one.
The widespread method of restoration with aluminum tape is also absurd. Not only is the effect of such a repair short-lived (up to 2,000 km), but the risk of jamming the brake caliper also increases dramatically. Concerns arise from the fact that the wear products of the aluminum adhesive tape get caught in the gap between the bracket and the guide.
Manipulation of the brake caliper bracket
Replacing the bracket is one rational solution to fixing a knocking caliper. However, you need to be on the lookout for a new part. A fresh part is not always distinguished by the quality of the manufactured holes for the guides. As a result, it turns out that even with a new caliper bracket, the calipers keep knocking.
A good tip on this point is to try the pins on the caliper before you buy it. It is necessary to bring with you exactly those guides that will be installed in the future. It is also worth being vigilant: the guides, which the car was equipped with from the factory, are usually of better quality than alternative products from the store.
However, in terms of efficiency, this method is ahead of another solution: the bracket without holes. The advantage is that the drilling of the holes for the pins is done by your own, taking into account the actual dimensions of the available guides. Of course, in this case you can achieve the minimum clearance between the pin and the bracket hole, as long as the quality of the work is not compromised.
A worthy alternative to a new bracket is restoration of the existing product. The essence of the work is as follows:
- Select rubber rings to fit in the brace sockets.
- Bore holes in the bracket for these rubbers.
- Turn out new guides.
- Assemble the construction: install the rubbers in the bracket and insert the guides.
It is noteworthy that the guides of some cars are equipped with rubber rings already from the factory. When selecting rubber bands, it is important to consider the heat resistance and resistance to technical fluids. Judging by the discussions of this method on the web, rubber is often sought to be replaced by fluoroplastic bushings. Oil caps are also commonly used for this purpose.
Other methods
As for the springs and ties used to fix the caliper, they are practically useless. Another thing is the installation of spring clips over the caliper. This solution is used quite often and the result is really positive. The disadvantages of this approach are obvious – skew caliper and, as a consequence, uneven wear pads.
To fix the problem often put modernized pads with a rubberized nonoperating part. Bending the noise-canceling plate of the caliper, if available, also saves the trouble.
