How to sharpen brake discs with your own hands

Do-it-yourself brake disc grooving

A popular procedure among many car enthusiasts, re-grooving brake discs and drums is a good way to extend the life of critical parts.<\p>

Scratches and grooves formed on the working surface of the part affect the operation of the entire braking system. They arise for various reasons. Among the most likely:

Dirt and foreign objects such as sand, small pebbles, glass shards or metal shavings get into the gap between the friction lining and the disc surface.
Souring or uneven operation of the cylinders and calipers pressing on the pads.
Distorted brake pads due to improper installation.
Poor quality friction lining material.
Overheating and disk deformation.
Natural wear of metal due to friction.
Late replacement of brake pads.

All this is not at all a reason to send expensive components for scrap. Many problems can be avoided if the necessary measures are taken in a timely manner. It is much wiser not to think about how to groove brake discs with your own hands, but to prevent the occurrence of a malfunction.

Entry of dirt and foreign objects

Most often, a problem is signaled by extraneous noises that occur not only during braking, but also when the car is moving in various modes.

It can be either a quiet rustle or a grinding sound that hurts the ear.

When the first suspicions arise, it is worth inspecting the components of the brake system, clearing them of foreign objects and contaminants. In the case of disks, this usually requires blowing out the components with compressed air or removing the foreign object with a screwdriver.

It's more difficult with drums. They definitely have to be removed. If scratches and grooves are found on the metal surface, it means that discs or drums need to be resurfaced. The sooner you do this, the greater the chance of extending the life of the damaged part.

Souring or uneven operation of the cylinders

Souring of calipers and cylinders is a frequently occurring problem associated with damage to the protective boots or the fact that the car has not been used for a long time. In both cases, corrosive damage to the surface of the pistons occurs with the formation of a rather thick layer of oxides on them, which impedes the normal operation of the mechanism. The following steps must be taken:

Restore the mobility of components by cleaning them from corrosion.
Replace damaged boots and seals.

But if measures to eliminate the malfunction are taken late, the damage to the working surface of the disk or drum is great, and grooves cannot be avoided.

Grooving brake discs. Video:

When carrying out regular maintenance of the brake system, you should pay special attention to the correct installation of parts during the assembly process. Otherwise, a situation may arise when the friction linings press unevenly on the surface of the drum or disk.

This will result in reduced brake performance and damage to parts that will require repair or replacement.

Poor quality friction lining material

When purchasing a set of new brake pads, pay special attention to their quality. It is unacceptable for the friction lining material to contain solid inclusions.

Some manufacturers add metal shavings to the mixture, which increases braking efficiency, but accelerates the destruction of discs and makes them wear unevenly.

It is better to avoid purchasing such components.

It should be borne in mind that many companies adapt the composition of the friction lining mixture to the composition of the material from which the discs and drums are made. If so, then it makes the most sense to purchase spare parts manufactured by the same company. This way you will ensure optimal operation of the brake system components, extending their service life.

Disk deformation due to overheating

An unpleasant breakdown that results in the car pulling to the side and the brake pedal pulsating when braking. Among the most likely causes of the problem is too intense braking followed by sudden cooling, for example, getting into a puddle.

The stronger the deformation, the less likely it is to fix the problem by turning the disc. Drums are subject to such damage to a much lesser extent.

Natural wear of metal due to friction

Since the dimensions of the friction linings do not completely coincide with the dimensions of the disc or drum, a protruding edge forms on the working surface of the latter over time, interfering with the operation of the brake system components. To remove this edge, you should grind the brake discs , first making sure that they are within the permissible dimensions.

Brake disc groove. Video:

When the linings are completely worn out, the friction that occurs between the metal surfaces of the pads and the surfaces of the discs or drums quickly destroys the parts. Some cars are equipped with special wear sensors. If they are not there, you should regularly check the brake system yourself.

Not an easy task

For obvious reasons, many car owners are interested in how to sharpen a brake disc with their own hands. At the risk of disappointing them, we will try to answer honestly. It is impossible to carry out such work without special equipment and certain skills.

You should not try to process the surface of a part whose dimensions must be maintained to within hundredths of a millimeter using sandpaper, much less a file. There are only two options:

Turn the brake discs on a regular lathe.
Use special equipment designed to perform this type of work.

Any other processing methods will not give the desired result.

Grooving on a lathe

Not everyone can use such equipment. A lathe, which has the necessary accuracy and has dimensions that allow it to process large-diameter parts, sometimes costs more than a car. There is no point in buying it to periodically solve a narrow range of problems.

But even if you have access to equipment with the necessary parameters and you have the appropriate skills, turning brake discs or drums without making special equipment will be impossible.

The fact is that it is impossible to install the part on the machine with the required accuracy simply by spreading the chuck jaws in the central mounting hole. We will have to act differently. Have to:

Make a special mandrel that matches the shape and size of the wheel hub and has a shank that can be clamped in the chuck. The accuracy of the radial and axial runout of the mandrel should be no more than 0.03 mm.
Attach the disk or drum to the mandrel (for this you can use the standard fastening system), and then install the mandrel itself into the cartridge.
Having installed a cutter of a suitable size, groove the working surface of the disk or drum. Runout parameters should not exceed 0.05 mm with surface roughness Rz

In the case of drums, this approach is quite justified. But if we are talking about turning brake discs, then a lathe is not the best way to solve the problem. Fortunately, there are other methods.

Groove without removal

Modern industry produces special equipment that makes it possible to perform work directly on the car without removing it. This approach is justified. After all, a wheel hub rotating on bearings certainly provides the necessary conditions for precise machining of the part.

Replacing brake discs. What do you need to know? – there is more useful information here.

Is it worth purchasing a machine for turning brake discs, the cost of which is at least 100 thousand rubles? for your own needs, you will have to decide for yourself. You will have to act in the following order:

We install the car on a strong and rigid support. A jack will not work here.
We remove the wheel.
We dismantle the caliper and clean the disc from foreign contaminants, at the same time making sure that it rotates freely.
We install a special adapter on the hub and accurately center it, connecting the rest of the equipment to it.
We position the cutter(s) strictly perpendicular to the wheel axis.
We turn on the machine and, after waiting until it spins the hub to the required speed, we process the surface of the part.

Taking into account the fact that on most models of this type of machines most of the settings do not take much time, the work is greatly simplified. But, obviously, in the absence of special equipment, the question of how to groove brake discs without removing them with your own hands loses all meaning.

Trust but check

Taking into account all of the above, it is better to entrust the work to professionals who have the necessary equipment at their disposal. But even here, car owners can expect pitfalls. For example:

You cannot work on the drive axle of a vehicle without dismantling the part or disconnecting the drive shaft from the wheel. Failure to comply with this rule can lead to breakdown of both the processing machine and the transmission of the machine being serviced.
To achieve the required roughness parameters of the working surface, the capabilities of an ordinary cutter are quite sufficient. Therefore, the statement that the car will have diamond-cut discs is most likely an attempt to get more money from the owner. There is no real need to use diamond cutters.
Before starting processing, be sure to make sure that the part is within the acceptable dimensions. Otherwise, you may waste your energy, time and money.

But if you do everything correctly, you can save money by breathing a second life into parts that still retain their service life.

Source: https://autoot.ru/protochka-tormoznyh-diskov-svoimi-rukami.html

Grooving brake discs with your own hands, how to restore them without removing them

Good day, dear motorists! And again we return to one of the main components of the car’s braking system – brake discs. Brake discs, along with brake pads, are the last element of the braking system that carries out the process of braking and stopping the car.

That is, everything: the brake pedal, the brake master cylinder, the brake wheel cylinders, the entire work of this system is aimed at the moment of truth - when the brake pads compress the brake disc and the car stops or slows down.

It would be completely unnecessary to remind you that serviceable brake discs are our chance to avoid an accident. This means that timely maintenance and repair of brake discs is a priority.

Today we will talk about one of the repair methods - grooving and grinding brake discs. To determine their condition during daily use, there are proven traditional diagnostic methods.

Diagnostics of serviceability of brake discs

Grooving on a lathe

Preliminary diagnostics of the brake system has a number of specific parameters, knowledge of which allows the driver to notice a brake malfunction in time.

the brake discs began to heat up;
when braking, you feel vibration in the steering wheel or brake pedal;
A visual inspection allows you to see traces of deep rust or mechanical damage to the brake disc.

All this suggests that the time has come for repairs - the brake discs need to be polished. This is in addition to the fact that there are manufacturer requirements for the minimum thickness of the brake disc, after which operation is strictly prohibited and the brake discs must be replaced.

Why do you need a boring?

Groove without removal

Grooving brake discs is an effective method for extending their safe operation life. No matter how you drive quietly and slowly, the brake discs.

Sooner or later they become unusable: emergency braking leads to overheating, increased air humidity leads to the appearance of deep corrosion (visible rust), rare use of the car also causes rust on the brake discs.

A worn brake lining causes mechanical damage to the disc mirror, plus dust and fine sand. In general, there are a lot of factors that lead to disc wear. There is only one way out - boring the brake discs.

What is grooved brake discs?

And, in fact, how to find out that it is the grinding of the brake disc that is required, and not the replacement of brake discs.

For a number of reasons, the working surface of the brake disc begins to acquire grooves, and so-called grooves are formed along the edge of the contact of the brake pad to the disc. "Beads".

Turning brake discs means that surface defects are removed from the working surface of the disc using a machine for turning brake discs. How much to shoot? For each model, manufacturers set a minimum thickness.

These numbers from manufacturers are the norm. And you will see them either in the manual, if you have standard discs, or in the operating instructions for the discs from the manufacturer.

Or maybe turning brake discs isn't worth the cost? Maybe it would be easier to buy new disks? But, do not forget that you need to buy a pair for simultaneous replacement on the same axis.

In addition, it is advisable to replace the brake pads at the same time as the brake discs. This is in case the disc wear is caused by defects in the brake pad. If your family budget doesn’t mind, then you can buy new wheels.

Technologies and equipment for grooving brake discs

In the recent past, motorists did not have a question about where to sharpen brake discs. They removed the discs and took them to the nearest workshop with a lathe. It was a complex technological process.

After all, grooving a brake disc is not just about removing the top layer of the working surface. In addition to this work, you need to comply with all balancing parameters regarding the disk and wheel hub.

In the hands of a modern specialist there is a miracle - a machine for grooving brake discs, in which all parameters are programmed, and the disc is polished automatically. Moreover, there is absolutely no need to remove the brake disc from the car.

Grooving of brake discs and removal is carried out on a stationary boring machine. Processing of the working surfaces of the disk is carried out simultaneously on both sides, and ensures the adjustment of all necessary parameters for the thickness and balancing of the disk.

Grooving without removal occurs using a portable grooving machine. The base planes when grooving with a portable machine are the places where the caliper is attached. As a result of grooving, we obtain absolutely parallel surfaces of the disk.

As a result of professional grinding of the brake disc using special equipment, we get:

eliminating brake disc runout;
the efficiency of the braking system increases;
the service life of brake discs increases;
We see real savings in the family budget.

It is quite possible to drill a brake disc yourself. But, for this you will need to fulfill two mandatory conditions: to be a qualified turner, and to have a lathe in your garage, at a minimum. In all other cases, it is better not to take risks and not conduct experiments for your own safety.

Source: http://CarTore.ru/122-kak-protochit-tormoznye-diski-svoimi-rukami.html

How to Sharpen Brake Discs Yourself

Brake discs: No need to replace

Eight? We're filming...

The appearance of axial runout of brake discs is almost inevitable when operating vehicles with intense braking, which is typical for Russia with its nervous situation on the roads.

Warping from overheating, sudden cooling when water gets in from puddles, uneven wear, and now the disc, writing a “figure eight”, constantly moves the pads to the sides, increasing the free play of the pedal and reducing the effectiveness of the brakes.

When diagnosing at a dealership technical center, they usually give a verdict: the discs need to be replaced. And this is fair, because safety comes first. But... It turns out that the part is common, but the price is not particularly common. A pair of original wheels, for example, on a Mercedes-Benz Actros costs 22,000 rubles!

...and grind (1)

There is a much cheaper solution to the problem - to grind the end surfaces of the disks, restoring the perpendicularity of their planes to the axis of rotation. There are several ways to do this.

The most primitive, requiring only a lathe decommissioned from a vocational school classroom, requires removing the disk from the hub. It is long, labor-intensive and, most importantly, ineffective.

After all, after mounting the disk on the hub, the possibility of axial runout remains - it is almost impossible to meet the standard of no more than 50 microns.

By the way, if the disk runout is also caused by deformation of the hub itself, which often happens on our bumpy roads, then the new disk will show a “figure eight”.

Seeing this, the dealer serviceman will charge you another ten thousand rubles for a new hub.

... we grind (2)

Another way is to leave the disc on the car and sharpen it with a cutter attached to the brake caliper. The result will be good, and even a defect in the hub will be compensated by processing the disc strictly perpendicular to the axis of rotation.

But the labor intensity here is even higher than with the first method.

Especially if you have cars of different brands and models in your fleet: you will have to make individual adapters for installing metalworking equipment on the caliper mounting eyes.

... we grind (3)

And finally, the most progressive method: you need to use a special installation for grooving brake discs, which allows you to not remove anything from the car.

If it is manually adjusted, then the carrier will have to keep a very qualified specialist on staff in the repair zone (or rather, retain him using the “carrot” method), who is not characterized by even the slightest trembling of his hands. Because an ordinary car mechanic, even a very smart and diligent one, will inevitably make a mess. Unless, of course, he works part-time in his free time as an 8th-grade fabricator or a sniper.

What about the market?

Fortunately, the market also offers special equipment with automatic settings. For example, produced by the American company Pro-Cut International, represented in Russia by Barclay Holding. Almost any auto mechanic can fix brake discs with this.

Thanks to the presence of a gyroscopic sensor and actuators, the computer will set the cutters to the desired position within 20-40 seconds, and the error will be no more than one micron. This is an order of magnitude less than the tolerance with which the discs are machined at the manufacturer.

The hub is rotated by an electric motor.

Of course, in this case a special adapter is used with the same PCD parameter as on the wheels used on this car - that is, corresponding to the diameter of the thread of the mounting studs and the diameter of the circle of their location.

The repair time for one disc is about 10 minutes, and it becomes thinner by only 0.2-0.3 mm, which is significantly less than its natural wear between replacing a set of pads.

That is why some car companies that officially recommend that their authorized service centers purchase Pro-Cut equipment advise grinding the discs every time the pads are replaced.

At the same time, the working surfaces of the discs are strengthened, and the running-in time of the pads is reduced to a minimum.

If you have a garage with a dozen cars that run about 100,000 km annually, the Pro-Cut equipment should pay for itself in less than two years, because the kit costs only 270,000 rubles.

Do-it-yourself brake disc grooving

Content

What is grooved brake discs?

Methods and equipment for turning brake discs

1 What is grooving brake discs?

How do we keep our car's braking system in good working order? Based on the manufacturer's requirements to replace the pads after a certain mileage and based on diagnostics of the brake system. vehicle reaction to braking and visual diagnostics of the condition of brake discs and pads.

One of the ways to extend the life of a brake disc, along with its systematic maintenance, is to bore (groove) the brake discs.

You understand that during braking, not only the brake pads wear out, but also the brake disc itself. The working surface of the brake disc begins to acquire grooves, and “shoulders” form along the edges of the pads. We will not consider the physics of this phenomenon, but will immediately move on to the question of how and where to sharpen brake discs.

Some may ask: why sharpen brake discs if you can buy them? In principle, it is possible, but you, or rather your budget, will get tired of buying, since modern car models are equipped with completely expensive brake systems.

Actually, for this reason, there is a groove of brake discs and, accordingly, a variety of equipment for groove of brake discs.

Grooving of brake discs is the removal of surface defects from the brake disc to the thickness of the disc allowed by the manufacturer. You will find these numbers in your vehicle's Owner's Manual.

2 Methods and equipment for turning brake discs

Previously, everything was simplified - turning brake discs took place on a lathe, for which the discs were removed and taken to the workshop. This type of disc cutting took at least half a day.

After all, the task is not just to remove the top layer of the brake disc, but at the same time to observe all the balancing parameters regarding the disc itself and its placement on the hub.

As you can see, the task is not easy.

Today's technologies and equipment have led to the fact that turning brake discs without removing them from the car is the most common and optimal option. In this case, the machine for grooving brake discs adjusts all the necessary parameters: the thickness of the brake disc and balancing, conditionally – automatically.

Grooving and removal of brake discs is carried out on a stationary machine. Processing is carried out simultaneously on both sides, with the processing plane corresponding to the plane of pad rubbing.

Grooving of brake discs without removal is carried out using special portable equipment for grooving discs. The base planes in this case are the place where the caliper is attached.

The practice of grooving brake discs in both cases shows that grooving machines make it possible to maintain the alignment of the axles and discs. The result of grooving the brake disc is absolutely flat and parallel working surfaces of the disc. 100% wobble-free guarantee.

When asked by motorists where they can sharpen brake discs, there are three possible answers: either in a specialized service center, or in a workshop of a familiar turner, or you can sharpen the brake discs yourself.

The second option - it depends on the qualifications of the turner, and whether you have free time to remove the disks. Guaranteed alignment - the words of the master, nothing more.

For the third option, you will need at least a grooving machine. And taking into account the cost of the equipment and the fairly large frequency of grooving the brake discs, it will not pay off soon. Therefore, nevertheless, the best option is a car service.

Good luck, car lovers.

Do-it-yourself brake disc grooving

Source: http://www.1km-auto.ru/nekotorye-rekomendacii/kak-samomu-protochit-tormoznye-diski.html

Grooving brake discs and drums

During braking, the pads are pressed against the disc or drum. Due to friction, heating and abrasion of all elements of the brake system occur.

Over time, beads appear on the outer surface of the disc or inner surface of the drum as a result of wear, which, when installing pads of a different type or size, reduce braking efficiency. When water gets on a hot disk, uneven cooling occurs, as a result of which the disk bends and beats appear.

To correct these problems, the discs and drums must be replaced. But the cost of these parts, especially for foreign cars, is high, so drivers often grind them instead of replacing them.

In what cases should you not grind a disc or drum?

Each brake rotor or drum has a minimum thickness before replacement is required.

When the thickness decreases below this limit, there is a danger of pistons coming out of the working brake cylinders, loss of brake fluid and a sharp deterioration in the performance of the brake system. This danger occurs when the pads are worn to more than half their thickness.

The minimum thickness of the disk, after which its operation is unsafe, is indicated on its end. Before starting grooving, measure the thickness of the worn part of the disc in 5–7 places. This is necessary to not only determine the actual thickness, but also to detect uneven wear.

If the thickness according to the measurement results differs by more than 0.05 mm, such a disk can only be sharpened in a workshop. If the thickness is equal to the minimum value indicated on the end of the disk, it must be replaced.

After all, during grooving you will have to remove part of the thickness and its operation will become unsafe. The method for checking drums is similar.

It is also necessary to determine whether the disk is bent and, if so, how much. This can be done using a thread and a weight. Fasten the thread parallel to the outer plane of the disk and rotate the hub.

If the disc is bent, you will see the weight wobble and the distance between the string and the plane increase. Determine the curvature by increasing the distance and amplitude of movement of the weight. Then subtract the curvature from the thickness of the worn part of the disc.

When the thickness is greater than the minimum value, the disc can still be ground; if it is equal to or less, it must be replaced.

Carefully inspect the entire surface of the disc. If cracks are detected, the disc must be replaced regardless of thickness. Operating a disc with cracks is deadly. Under heavy loads or temperature changes, there is a high probability of disc destruction and pistons falling out of the brake working cylinders. This fully applies to brake drums.

How to sharpen a brake disc or drum

There are the following types of groove:

in a workshop (lathe);
by car using a cutter and a manual machine;
on the car using a file or whetstone.

Grooving in a workshop is most effective. It allows you not only to cut off the beads, but also to eliminate runout. For such a groove it is necessary to remove the disc from the hub.

To do this, in most cases you will have to treat the joint between the disc and the hub with WD-40. Then knock down the disc using a rubber or wooden hammer. Grooving in a workshop allows you to identify hub runout.

In this case, the hub must be replaced.

To groove using a cutter, you need to purchase a manual machine. The cost of the machine in most cases significantly exceeds the price of the discs, so it is purchased only for auto repair shops. To sharpen discs or drums with it, follow the instructions in the operating instructions.

Grinding with a file or whetstone is a temporary measure because it only removes the beads. With its help it is impossible to eliminate disk runout.

To sharpen a drive wheel disc, start the engine, shift into high gear, and press a file or whetstone parallel to the inside surface of the disc. Then repeat this operation for the outer surface of the disk.

Press the stone or file for 20 - 30 seconds, then remove and inspect the result. If necessary, repeat the process until the desired effect is achieved.

To machine the discs of non-driving wheels, they will need to be screwed to the hub using wheel bolts or nuts. In this case, you will need to lift the front and rear, first the left, then the right side of the car. The same is necessary for grooving the brake drums of the rear axle.

The technology for removing and installing the brake disc is described in the article (Replacing front and rear wheel bearings). To learn how to properly remove a brake drum so as not to damage it, read the article (how to remove a brake drum).

After grooving, the disc or drum must be rinsed with a stream of water and wiped dry with a rag and new pads must be installed.

Video - How to sharpen a brake disc at home

Source: http://VipWash.ru/tormoznaya-sistema/protochka-tormoznyh-diskov-i-barabanov

Grooving brake discs without removing, do it yourself

The brake system of a modern car can often be serviced only at specialized service stations.

The owner’s qualifications do not always allow him to cope with complex devices and components, and garage equipment for servicing, say, ABS, is simply not enough.

However, everyone can perform simple operations, such as replacing pads, and at the same time check the condition of the working parts of the system.

Content:

What types of brake pads are there?

The degree of wear of a disc or drum is greatly influenced not only by driving style and road conditions. The surface of the friction linings of the brake pads, perhaps, affects the wear of the system most of all. Brake pads are divided into several types based on the material used to make the friction lining:

metallized;
synthetic;
ceramic;
asbestos-containing.

Friction linings containing asbestos are not currently used, since the use of this material is prohibited. Harmful hurts.

Therefore, it is being replaced by other synthetic materials with similar properties. The main thing you need from a brake pad is to withstand wear and temperature.

The pad can heat up to 600 degrees, and this affects both disc wear and friction lining wear.

The influence of friction linings on discs and drums

But now we are primarily interested in the effect of the pads on the condition of the brake disc.

Soft synthetic semi-metallic brake pads wear out the brake disc the least, but are not as effective in braking. They make little noise, but during operation they create quite a lot of dust.

The resource of soft pads is small, and they are designed for a quiet and comfortable ride. Then they don’t wear off so quickly.

Stiffer brake pads are designed for aggressive riding styles and are harder than synthetic pads. As a rule, the metal content in them is 30-45%. Copper chips, graphite, and thin steel fibers can be used as filler.

Metallized pads are noisy in operation, but they are very tenacious and do not wear out as quickly as synthetic pads with a low metal content. But they wear out the brake disc the most, and sometimes they can overheat it.

Here it is not far from warping of the surface, which not every grinding and grooving will correct.

Methods and tools for detecting disk failures

The deterioration of the brake system is visible to the naked eye and no special stands are needed here. Signs of wear on brake system consumables are simple:

Indistinct response to the brake pedal.
Increased noise, creaking and squealing of brake pads and discs.
Vibrations and beats when braking.
Brakes overheat under normal conditions.

This is easy to check visually, without even disassembling the brake mechanism. It is enough to measure the level of wear on the pads and discs or drums, and the situation will become clearer. The manufacturer indicates the permissible thickness of the brake disc at the end.

But, as a rule, you don’t have to look for the inscription, but start from the value of 10 +- 2 mm. The thickness of the linings for each car is allowed to be different, and here it is better to scroll through the Murzilka for the car. But there will be no news there either.

The average permissible thickness of the friction lining is at least 2-3 mm.

Why grind brake discs?

Now you can put the caliper and micrometer aside and simply run your fingers along the surface of the brake disc. It is all pitted with wear and tear. The deeper the grooves, the more the disc eats up the pad.

And the harder the friction lining, the greater the likelihood of ruts appearing. Now let's pay attention to the shoulder that has formed as the disc wears out. It is sharp and sometimes you can cut your finger on it.

What about the brake linings?

This is why brake discs are ground. And after grooving, they also grind it in order to bring the working surface to the ideal condition as much as possible.

Thus, after grooving, the disc becomes even and smooth and will last for quite a long time. But the groove is not omnipotent, and if the disk has suffered from overheating, no one will sharpen it.

Firstly, the structure of the metal is no longer the same, and secondly, eliminating the disc runout with a groove is a rather dubious method.

Grooving brake discs - how, with what and where

Grinding brake discs without removing them yourself is only possible if you have a Dutch MAD disc processing machine lying around in your garage. But this is unlikely, because it costs about 4 thousand euros. Not every service station can afford such luxury.

But if a station offers such a service, that’s great. Because turning discs without dismantling saves a lot of time, turning is carried out at the highest quality level, and after turning, the stand also does grinding. This is what it looks like at work. Nice to watch.

You can go another way. Remove the brake discs and take them to a familiar turner. But where is the guarantee that the machine is not pre-reform and that it will perfectly grind the surface without a hint of beating? There is no such guarantee. Therefore, if it is possible to sharpen a disc without removing it on a special stand, do not be greedy. A new disk costs a hundred times more, and it’s simply stupid to measure security in money.

The more attentive we are to the brake mechanisms, the longer and more efficiently they will last. Therefore, maintain your brakes on time and efficiently, and your car will always stop where you want it, and not where it doesn’t. Slow down in front of potholes, and good luck to everyone!

Read also: Replacing kingpins on a UAZ Patriot

Source: http://LadaMaster.com/protochka-tormoznykh-diskov-bez-snyatiya

Do-it-yourself grooving of brake discs without removal (video)

The most important thing for ensuring safety when driving a car is, without a doubt, the braking system. And the condition of the working surface of the brake discs greatly affects the performance of the entire system. The average service life of a brake disc is about 70 thousand km.

The car has a much longer service life. Therefore, the need to replace or repair these parts appears from time to time in the life of every car owner.

In cases where the defects that arise are minor and are not associated with temperature deformation, excessive wear or cracking, turning the brake discs yourself without removing them is an inexpensive repair method.

When is a groove necessary?

Signs of need for grooving:

Wave-shaped work surface.
Scouring on the working surface.
Excessively rapid wear of brake pads with the same driving style. On average, a set of brake pads lasts for 30 thousand km.
The brake pedal shakes during braking.

Several ways of grooving without removal

Whatever method of turning brake discs you choose, before you begin, make sure that their thickness is greater than the maximum permissible and that they are not cracked.

If they are too thin or have cracks, don't risk repairing them. Better buy new ones.

Grooving is the leveling of working surfaces using a cutter, and the methods proposed below are grinding brake discs without removal.

There are special units for grinding brake discs without removal. But I think you will agree with me that it is not worth buying a unit just to grind a couple of discs. It will be cheaper to completely update the brake system.
If the disks are on the drive axle. You will need a flat wooden block measuring 30x15x5 cm and several sheets of sandpaper with coarse abrasive grain (for example, No. 40) on a fabric base. Using sandpaper and a block is preferable to using an abrasive wheel for sanding. Because the working surface of the abrasive wheel will soon cease to be flat after the start of grinding. And the plane of the sides of the block will not change during operation. Don't forget to change the sandpaper - this will speed up the sanding process and improve its results. Raise the car with a jack and put some kind of insurance under it. Remove the wheel, brake caliper and brake disc boot. Hang the caliper higher so it doesn't interfere. Start the engine, put the gear in gear, and adjust the rotation to your liking. Lay a sheet of sandpaper with the abrasive down, place a block on it with the wide side, and bend the edges of the sheet protruding from under the block upward. Press the resulting structure alternately with its wide edge against the working surfaces of the brake disc. Do not try to press it harder, it is better to move the point of contact all the time.
Brake mechanisms located on a non-driving axle are ground without removal using the same device made from a block and a sheet of coarse sandpaper. Only it will not be the disk that will move, but the block with sandpaper. It will be moved by the strength of your hands. But to tell the truth, doing this without removing the disk is very inconvenient; things will go much faster if you remove them and put them on the workbench.
Grinding brake discs on the go. This method is suitable for restoring disks located on both the drive and driven axles. But it is suitable for eliminating only minor defects. It will not be able to eliminate the result of severe temperature deformation. First, special devices should be made from old brake pads. To do this you need a grinder with a diamond cutting disc. And also an abrasive cleaning disc for it. It is necessary to cut two wedge-shaped segments from the grinding wheel. Make two recesses in the old brake pads in accordance with the shape of the wedge fragments. Their depth should be a few tenths of a millimeter less than the thickness of the abrasive inserts, so that the latter, after installation, rise above the surface of the pads. Insert the sectors into the recesses, having previously lubricated them with some kind of glue so that they do not fall out. Install the resulting “abrasive pads” into the caliper instead of the standard ones. To sharpen working surfaces, you need to drive from 5 to 10 km, braking periodically. Plan your route to avoid sudden braking or slowing down on bumpy areas. During the trip, monitor the result of grinding. The bead formed around the perimeter of the disk can be removed after the end of the trip with an ordinary file with a large notch.

After leveling the working surfaces, it would not hurt to treat them with finer-grained sandpaper in order to reduce the depth of the marks. You should not immediately use fine-grain sandpaper, because it will make the surface less smooth and the surface will be smooth, but wavy.

Where to look for a fault

The beating of the front discs is often reflected not only into the pedal, but also into the steering wheel.
The rear beating is better felt through the vibrations on the body.
The front mechanisms more often suffer from thermal deformation, since they bear the main load during braking, therefore, they heat up more. Deformation occurs as follows. When braking, the disc heats up and expands evenly. Water that gets onto a certain area quickly cools it, and as it cools, it shrinks and warps the entire part.
The rear ones are more susceptible to corrosion. Since, due to their low load, water that gets on them does not dry out for a long time.

Source: http://AutoLirika.ru/remont/protachivaem-tormoznye-diski-svoimi-rukami.html