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Step-by-step instruction: replacing drum brakes with disc brakes


Most modern cars are equipped with disc brakes front and rear. On budget models, the rear axle is still drum. These mechanisms are considered obsolete long ago. But why do manufacturers equip cars with such brakes? Most likely, the point here is the banal desire to save on production. Drum brakes work, but their efficiency is not too high. Replacing drum brakes with disc brakes should improve the result. Let's see if this is so and whether it is worth performing this replacement.

Drum brake device

Consider the construction in general. This system uses two semicircular brake pads.

They are installed inside the brake drum. On one side, the pads are fixed quite rigidly, and on the other hand, they develop with a piston. The latter works when the driver presses the pedal. And the higher the force, the stronger the piston will extend.

Between the two pads installed springs. When the driver releases the pedal, these springs move the pads to their base position. They are used so that the drum does not jam.

As you can see, the drum brake is really simple in design. But the progress and development of modern technology is constantly moving forward, engines are developing. Those speeds that at the dawn of the automotive industry seemed somehow unrealistic, today have become invisible. Often on the highway, cars move at speeds up to 200 km / h. Such a speed, even for motorsport champions 40 years ago, seemed fantastic.

At these speeds, the drum brake is no longer able to cope with its main task. Efficiency is lost. The first and only brake problem of this design is overheating of the pads. Hence the deterioration of work efficiency.

With the growth of speeds and capacities, engineers and designers faced the difficult task of improving the braking system. And there was nothing left to do but seek help from the aircraft industry. That's right, because the first disc brakes were installed on airplanes. Further, the system successfully switched to cars.

Device disk mechanisms

The disk element was considered a new round in the development of brake systems. Previously, it was installed only on aircraft, as well as huge trucks. There is higher speed and more mass. Let's see how this system works and whether drum brakes can be changed to disc brakes.

So, a thin disk is fixed on the axis of the car. It can be both front and rear axle. In the upper part or on the side of the disk, a so-called caliper is fixed. Its mechanism includes pistons and brake pads. When the driver presses the pedal, the pads are compressed by the piston. Between these elements is a disk. This is how braking occurs.

Disc Brake Features

The disk mechanism is more productive. The fact is that the contact spot is not semicircular, as on the drum system, but parallel. Due to this, the pads are pressed very tightly to the surface of the disk. This makes it possible to brake much more efficiently at high speeds. Replacing drum brakes with disc brakes really allows many times to increase the efficiency of the system.

Drum brakes warmed up, but disc brakes were also subject to stress. However, the drive cools better when driving. Also on the market you can find ventilated and perforated elements. Various notches can reduce the braking distance at times.

With all the advantages, there is a negative side. Since the contact patch of the disk with the block is higher, they wear out much faster. In addition, the disk erases faster. He is grinding off pads. The last resource for a disk brake is at least three times lower than the service life of a drum brake. How much brake pads are enough is hard to say. Wear rate depends on driving style. On average, disk pads with a calm driving style are enough for 25-30 thousand km.

Advantages and disadvantages of drum brakes

It’s worth starting with drum mechanisms. They have certain advantages. Drums are cheap to manufacture. Many car manufacturers with their help save on budget models. The drum brake has a significant resource. Pads change at large intervals (more than 100 thousand), which means that the owner will spend less money on maintenance.

The minuses include a small contact spot, low braking performance. Also, drum systems heat up more. And since their device is closed, the braking effect is further reduced. Finally, the drum element is more difficult to maintain.

Pros and cons of disk

Among the advantages, high efficiency of the braking process is distinguished. Also, this system does not heat up to such temperatures as their drum counterparts. The disc brake is easier to clean. The element is easy to change if necessary. Change them when the disk is thinner than a certain parameter. The minimum thickness of the brake disc is 20 millimeters.

The disadvantages include quick wear pads. Even expensive supplies have a small resource - only 30-40 thousand kilometers. Disks also wear out. They are enough on average for 100 thousand kilometers. Serving these brakes is more expensive than drum brakes. In the summer, squeaks are possible due to fake parts. It is also necessary to constantly monitor the degree of wear of the disk. It should be no thinner than 20 mm.

It is this minimum brake disc thickness that is regulated by most manufacturers. It is indicated on the end of the product and each manufacturer is different.

How to replace drum brakes with disc brakes

Which brakes are better - disc or drum? For modern conditions, the first type of mechanism is better. Speeds even in sparsely populated cities have increased. Engine power has grown, and every day more and more cars. To carry out the replacement, you must purchase two sets of brakes. Saving and buying the cheapest components is not worth it - jokes are bad with brakes.

Dismantling and installation of new elements

Replacement of drum brakes with disc brakes should be carried out in a garage with a pit, on a flyover or a lift. You can use the usual jack. First of all, they lift the car and fix it. Then remove the wheel. Next, unscrew the studs that hold the drum. This does not always work, since the studs often stick. Then remove the drum. It is more convenient to do this by tapping with a rubber mallet. Next, remove the parking brake cable, dismantle the brake cylinder. Pads and other parts are taken from the hub.

The installation site for new parts is carefully cleaned. There should not be any cracks or irregularities on the surface. If everything is in order, you can continue to work.

Install the hub, firmly pressing it to the faceplate. Then the nodes on the beam are straightened. Well, then everything is very simple - staples are installed on the faceplate, and a disk is installed on the hub. Be sure to insert distance washers. Further, the joints of the brackets are tightened. The hose is connected to the caliper, pads are installed. The integrity of the brake line is checked.

At this, the replacement of drum brakes with disc brakes is over. You can enjoy the efficient operation of the brake system.

Important points: what to look for?

If a motorist has decided to replace the drum brake system with a disk one, it is important to understand and take into account some significant points. This procedure is quite complicated and therefore requires special attention. Since the lives of people in the vehicle and outside it directly depend on the performance of the brake system, it is extremely important to consider the following points when changing the type of brake system mechanism:

  • When replacing the brake system, you will also need to replace the handbrake with a hydraulic,
  • When choosing a brake system, it is important to pay close attention to its compliance with the standards for such structures on a car,
  • Pay attention to the quality certificate of purchased disc brakes,
  • After the replacement, it is mandatory to undergo maintenance and notify of a change in design with a mark in the relevant documents.

How to replace yourself?

To independently carry out such a procedure, the contractor will need an installation set of a disk brake system, consisting of a caliper, pad, disc, hose, faceplates, bolts and fasteners. In addition, a standard set of automotive tools will be needed to complete the replacement. The procedure itself will look like this:

  • Remove brake pads according to instructions.
  • Remove the drum brakes,
  • Remove the nut supporting the parking brake cable and then unfasten the drum,
  • Disconnect the brake hose from the cylinder and then remove it,
  • Remove the hub and flange of the rear suspension arm,
  • Install disc brake system: connect brake hose, parking brake cable and caliper.
  • After installing the brake system, bleed it.

How to replace the drum brake system with a disk will be described in this video:

Why disk drives are better

Replacing brake systems is an important decision that must be supported not only by the desire to stand out, but also by common sense. Changing the safety design is a very important undertaking. Therefore, you should be aware of the advantages that disk braking mechanisms have over drum ones:

  • high braking performance due to uniform application of braking forces,
  • short braking distance of the car,
  • the braking mechanism is faster
  • improved functionality of pads and disc due to heat dissipation (especially interested in fast-driving enthusiasts).

These advantages should be enough to justify the need to change drum devices to disk.

On the video - the differences between drum brakes and disc brakes:

Some features of replacing braking systems

Like any manipulation with automotive systems, working with brakes has its own characteristics. You should be clearly aware that by changing the type of mechanism, you are changing the factory design of the car. These changes can lead to various consequences that you must be prepared for. So, features:

  1. Replacing drum brakes with disc brakes must meet all factory standards and requirements for your car model. Otherwise, you will be brought in during braking, the system may fail, the brake discs may overheat, etc. As you can see, the consequences of the mismatch are very different and quite unpleasant.
  2. New brakes must be certified for use in the Russian Federation. At the service station, where you will install them, you must be issued a certificate of their compliance with standards and requirements.
  3. The hand brake system will need to be replaced with a hydraulic handbrake.
  4. After the replacement, you will need to go through MOT, since you rearranged one of the factory systems. If you do not make changes, then in an accident it will automatically become its culprit.

If you are ready for such difficulties and they do not scare you, then you can safely replace the braking mechanisms on your machine.

Do-it-yourself braking system replacement

You can replace one type of mechanism with another at any service station. This is not an expensive procedure. Pros - professionals will not need much time for this and they will give you the appropriate quality certificate for the new brake system.

If you want to save on work, then you need to stock up on time and patience. Such structural manipulation of car brakes is not simple and certainly not easy. For its implementation, first of all, it is required to stock up with the necessary tool. In general, the replacement of pads is carried out with a standard set. In addition to this kit, you will need a disc brake installation kit. It includes:

  • caliper
  • hose,
  • pads
  • disks
  • faceplates,
  • bolts, washers and other fasteners.

On the video - replacing drum brakes with disc brakes:

When buying a car in the kit should go instructions for its use. It is written in black and white on the points, what needs to be done in order to replace the brake pads (they are erased from time to time and new ones need to be installed). With this instruction you can remove old drum mechanisms.

To install a disk system, you should read the instructions, which are also sold in the kit. In it you will find a detailed description, diagrams, etc.

Remember, for each model and brand of car the replacement of brake systems is carried out differently, but to be more precise, it has its own characteristics. Next, we will present you the main actions that are most unified.

So, first of all, you need to remove the drum brakes. To do this, remove all the mounting bolts that are on the rear wheels, fix the front with materials at hand and jack the required side with a jack. Caution, for safe operation, securely lock the vehicle. Now unscrew the bolts and remove the rear wheel.

Next, unscrew the nut that secures the parking brake cable. Now you can shoot the drum. Very often he sticks and needs to be torn off. For this you need a hammer. For greater efficiency, apply medium-power strikes with high frequency. After removing the drum, disconnect the brake hose from the brake cylinder. Remove it, a nave and a flange of the lever of a back suspension bracket.

Now we begin to install disc brakes. To do this, first fasten the flange of the suspension arm, and then the hub with the disk to it. Use only new bolts. Next, install the brake disc, the pad guides and the pads themselves. Before installing the caliper, wring out its pistons inward using a large flat screwdriver. Now you can put the caliper and secure the entire structure.

Video about installing rear disc brakes:

Next, you need to connect the brake hose, the parking brake cable and the caliper to the system itself.

After replacing the brake system, experts recommend pumping it and removing air from it.

From all of the above, the most important thing must be taken out. First, disc brakes are really more effective and will make the car safer, but any manipulation of factory parts is a structural change that should be recorded in certain documents. Second, for the independent replacement of these parts, time, place, special tools, knowledge and skills are needed.