Useful Tips

Replacing brake discs


Hello. I haven’t written for a long time, my thesis is on fire. But I still do a little car. Recently, I began to notice that braking a car has become less effective. And in the box are the long-bought brake pads and wheels of the company Brembo, At first I thought to take the car to a service, but knowing how these crooked-handed service men work, I decided to slowly and wisely approach this issue, clean it, lubricate it in the right places. All the same, brakes are personal security, and you should not trust your uncle Vasya, especially since the work is not so difficult ...
Part numbers I will lay out, but before you run headlong into the store, remove the wheel and see the diameter of the brake disc. At logans in different years of release, these details were different. My disk has a diameter 260 mm.
Disks: 08.A268.10
Pads: P 68 008
From the tool you need:
1. 17 "open end wrench
2. Spanner 13 "
3. 18 "head + ratchet
4. The hammer
5. Drill / screwdriver with a carriage, or a metal brush
6. Torex 40 "

From chemicals and lubricants I purchased:
1. Copper grease.
2. Heat resistant black paint.
3. Silicone grease.
4. Brake system cleaner 2 pcs.
5. Lubrication for the brake system (! not for guides!) Liqui Moly 7585 2 sachets.
6. Grease for guide calipers Liqui Moly 7656 2 sachets.

Painting a new disc:
Before starting work (if you need it), it is necessary to paint the disc so that by the time it is installed the paint has time to dry. We close unnecessary places with masking tape. We paint.

Removing the old brake disc:
1. Using a 17 "wrench (hold the guide pin) and 13" we unscrew the caliper guide bolts.
2. Remove the caliper and remove it to the side (can be put on the lever), pull out the pads.
3. Head 18 "unscrew the bracket bolts from the back of the fist, remove the bracket.
4. We turn off secret bolts holding a disk with 40 "Torex.
5. By gently tapping the hammer, knock down the sticky disk.
6. We clean the hub from rust.

Marginal resource

At each contact with the block, the disk wears out, although its thickness does not decrease as rapidly as the thickness of the friction linings. And yet there comes a time when wear exceeds acceptable limits. The minimum permissible thickness of the brake disc must be indicated by the manufacturer in the vehicle technical specification.

For others, replacement dates come after several tens of thousands of kilometers. Most car manufacturers make arrangements for the replacement of important components. But these are approximate figures, since many factors affect the pace and nature of wear.

Influencing factors

The choice of pads used to replace during the maintenance process has a significant impact. Most manufacturers have their own recipe for making friction linings. The physical characteristics of these pads may vary.

Much depends on the operating conditions of the equipment and the driving style of the driver. It affects the wear and tear of the whole system. Occurring malfunctions sometimes significantly reduce the resource of parts. The necessary recommendations are required to give dealership staff. But do not completely rely on their good faith.

To know when to change the brake discs, it is recommended to regularly inspect them and measure the thickness. Before proceeding with measurements, it is necessary to clarify the vehicle configuration option. Often, the same machine can be installed as ventilated brake discsand ordinary. They differ in size.

Depreciation of the surface on which the pads are pressed is uneven. This is due both to the structure of the friction linings themselves and to the ingress of foreign objects such as small pebbles into the gap between the block and the disk. To eliminate this, foreign objects must be removed in a timely manner. If the matter is in the structure of the friction linings, it is worth refusing to use parts of a not too conscientious manufacturer.

Dangerous overheating

The more intense the braking, the higher the heating. But if the temperature remains high even with prolonged movement with the pedal released, this means that the calipers do not brake because of the souring of their pistons or guides.

In this case, the wear of parts is sharply accelerated. The malfunction must be rectified immediately. Sometimes for this it is enough to clean the parts from dirt and rust. But repairs and even a complete replacement of the assembly may be required.

Possible options

Design features of the brake system depend on the intentions of the developers and the results obtained after preliminary calculations and tests. This affects the arrangement of individual parts, their dimensions and the material of manufacture. To increase braking performance, the following can be installed on the car:

  • Vacuum amplifiers that increase the pressure in the hydraulic drive of the system. If available, the multi-ton machine can be stopped by lightly pressing the pedal.
  • Calipers of increased efficiency, providing high clamping force on the pads.
  • Perforated brake discs. Due to the presence of holes or slots on the working surface, the part itself becomes lighter and the friction coefficient between the friction linings and the disk increases significantly. At the same time, pad wear is also accelerated. For this reason, such a solution is resorted to if other ways to increase the effectiveness of the brakes have been exhausted.
  • Carbon discs. The widespread availability of undoubted advantages of carbon fiber parts is hindered by the high price of this material. Such components so far can only be found on very expensive cars.

Important! If you have a desire to make independent changes to the design of the brake system, remember that this can only be done after agreement with the developer of the equipment. Otherwise, the converted car can only be used on sports tracks.

Car Owners Performing brake system repair their own car, or just interested in the device and the rules for servicing equipment, are often interested in the procedure for performing some work. We will tell about this.

How to remove the brake disc?

If there is no desire or opportunity to visit the service center, the work can be done independently. Of course, provided that you have the necessary conditions, tools and skills. Note that brake system repair It must be done carefully, and when disassembling and assembling the mechanisms, it is important to maintain cleanliness.

Replacing front brake discs

For successful work, it is recommended to use a hoist or jack in combination with reliable stops. Of course, depending on the specific model of the car, there are certain nuances. But the general sequence of actions on most modern machines is as follows:

  1. Weaken the tightening of the wheel bolts.
  2. Raise the car until the tire stops touching the bearing surface.
  3. We unscrew the bolts completely and remove the wheel.
  4. Unscrew the caliper cover either (depending on design) knock out the guides. After that, remove the brake pads.
  5. Since new pads should be installed together with the new disk, with the help of a flat mount we completely recess the caliper pistons. At the same time, we make sure that they move freely, and the anthers are intact.
  6. We turn off the caliper from the attachment points. To do this, perhaps to ensure convenient access to the bolts, you will have to turn the steering wheel in one direction or another. We remove the caliper and use the wire to suspend the suspension arm or car body on the shock absorber strut so that the hoses are in a free state. Sometimes, for this, you first have to loosen or remove the clamps holding the hoses.
  7. Unscrew the screw (or screws) fixing the disc on the wheel hub. After that, remove the part. It happens that she sticks to the seat on the hub. Then you have to use a liquid wrench, a hammer and a drift of soft metal.
  8. We clean the seat on the hub from dirt and rust and replace the new part by tightening the fixing screw (the screws).
  9. Degrease the working surface of the disc.
  10. We fix the caliper in place.
  11. Install the pads.
  12. Put the wheel in place.

Note! Details change only in pairs. It is not permissible to carry out work on only one side of the machine.

Replacing rear brake discs

The nature and order of operations, as a rule, does not differ from the work carried out on the front wheels. That's just to get to the places where the calipers are fastened sometimes from under the car. With a lift, this is not a problem. If there is only a jack, a viewing hole is required.

Although extremely rare, there are car models in which the wheels are made at the same time with the hub. In this case, you will have to replace the entire assembly.

It should be borne in mind that at the initial stage, until the pads are run-in, the braking performance will be slightly lower than usual. Some manufacturers of spare parts supply lapping paste complete with parts, which should be applied in accordance with the instructions for its use.

Which brake discs are better?

Of course, there are well-known brands whose product quality is proven by operating experience. Among them, one can mention Brembo, ATE, TRW. But on the one hand, new players are constantly appearing on the market, supplying products of a sufficiently high quality, and on the other hand, one can find a fair amount of fake parts on sale.

For these reasons, try to compose brake disc rating not worth it, and when choosing spare parts, it is recommended to pay attention not only to the big name of the manufacturer, but also to the general quality of the goods.

Since you cannot analyze the composition of the material from which the part you need is made, you should focus on the following parameters:

  • Exact compliance with the dimensions, due to violation of which assembly of the unit may be impossible. Poor balancing of the disc will cause its beating, the extreme manifestation of which is the pulsation of the brake pedal when pressed. Such components will have to immediately be sent to the scrap.
  • Processing quality. It is unacceptable if there is a flash on the parts, burrs or deep scratches. Conscientious manufacturers do not allow this.
  • Matching catalog numbers. They must exactly match those indicated in the technical documentation or on the website of the company that manufactured the part.

Too soft friction linings, when paired with a hard alloy disk, will quickly wear out. Hard pads, on the contrary, in a short time will render a part made of soft metal unusable.