Brake caliper rear and its repair. Piston caliper brake rear
After the traditional drumThe brakes became increasingly active disk systems, manufacturers had to look for a solution to one very urgent problem. The fact is that in disk it is necessary to provide not expansion of pads, but on the contrary - their compression. Consequently, the traditional constructive scheme proved to be unsuitable. However, the decision was found quickly enough. The first effective device, called "brake caliper rear", appeared at the turn of the 50-60s of the last century. How does it work and what are the features of its maintenance and repair?
Principle diagram of rear brake caliper of car
Systematic development of production technologiesdisk brake systems of the car has led to the fact that today the brake caliper support can have two different principal design schemes:
- the so-called "floating brace" design.
The purpose of both schemes is identical. They allow you to turn the brake caliper rearward into an active element that pushes the shoes to the wheel disc. But each of the designs has its own characteristics.
The fixed design of the brake caliper
Such a support consists of a metalthe central block fixed on a special pivoting fist and working cylinders with pistons symmetrically placed on both sides of the brake disc. In the inoperative state, the pads are held by the springs in the parallel disk at a certain distance from it. When the brake pedal is depressed, the brake fluid entering simultaneously through a complex hose system drives the pistons, which compress the pads.
Such a constructive scheme is considered the mosteffective for disk systems and is successfully used on cars with high engine power. It is this brake caliper rear mounted on most off-road cars, executive cars and sports cars.
Mechanism with floating bracket
The principal constructive differencesystem from the traditional disc brake is that one of the pads is always in a static position. The braking process is as follows:
- when the pedal is pressed, the fluid exerts pressure on the piston of the brake cylinder;
- thanks to the free running of the brace, the brake caliper piston leaves the cylinder casing and presses against the second brake shoe;
- Continuing its movement along special guides, the clamp presses to the disc and the second brake shoe.
This scheme is often used in various brands of cars.In particular, the rear brake caliper ("Opel" is not an exception) often has a "floating" structural scheme.
Importance of a working condition of a support
It goes without saying that trouble-free operationthis system of the car directly affects the safety of the owner of the car, passengers and other participants in the movement. Accordingly, the state of these elements requires increased attention to themselves. At the very first signs of malfunctions in the work of the support it is necessary to immediately contact the highly qualified specialists of the car service or service station!
The most typical malfunctions
The most common types of faults that are subject to caliper brake rear, are as follows:
- Corrosion and corrosion of the piston. As a result, the pressure of the brake fluid when the brake pedal is depressed is not enough to cause the piston to move.
- Sealing of sealing cuffs.This leads to an insufficiently effective clamping of the shoes. In addition, air can enter the system, which will result in insufficiently correct braking of all the wheels of the car.
- Outage of anther. In this case, dust and dirt accumulate between the piston and the cylinder, which leads to a difficult stroke of the piston, as well as to fluid losses.
- Damage to the movable bracket or its insufficienttightening. One of the most dangerous failures. If, for example, the brake caliper of the rear right is damaged by the bracket, then it can simply fall off when the braking is abrupt. The fluid instantly pours out, which will inevitably lead to a system failure on the remaining wheels.
Thus, careful control of the correct operation of the calipers is dictated by elementary considerations of common sense, own security and the instinct of self-preservation.
The most effective way to avoid problems,listed above, is professional diagnostics made by highly qualified specialists using specialized tools and equipment. The diagnostic process includes, as a rule, two stages of work:
- Checking the performance of the brake of each wheel. It is held on a special computer stand under the supervision of qualified experts.
- Visual inspection of calipers.This operation requires the removal of the rear wheels. Check the condition of the staples, body, cylinders and anthers. If damage is found, the parts must be replaced immediately.
If it is not possible to conduct a professionalDiagnostics brake caliper back (left or right - is not important) you can check yourself. However, the results of such an event can be approximate, which means that you will not reveal the problems in a timely manner.
Nevertheless check of serviceability of work of brake system of back wheels is carried out as follows:
- a smooth section of the road with good coverage and with the minimum possible traffic intensity is chosen;
- The car accelerates to a speed of 30 km / h;
- when the specified speed is reached, the clutch is squeezed out (or neutral mode is activated on the automatic transmission), and the brake pedal is pressed into the floor abruptly.
If the machine keeps course stability, thenthe system is in order. If it begins to enter, it often indicates a malfunction of the support. Determine from which side brake caliper rear defective, easy enough. The machine always "leads" in the opposite direction.
Repair and replacement
Like diagnostic work, and repairIt is strongly recommended to entrust brake calipers to highly qualified specialists. In addition to possessing all the necessary deep theoretical knowledge and rich practical experience, they also have a wide arsenal of specialized tools and equipment.
Typically, repairing the rear brake stuporincludes replacement of anthers and cuffs, adding a brake fluid and reinforcing the fastening of all structural elements. But this is the so-called current repair, which the car enthusiast himself can handle. But cracks on the bracket or on the working cylinder body, the damage to the guides, deformation of the pistons require specialist intervention.
Depending on the manufacturer and modelcar, the repair of the calipers of the disc brake system of the rear wheels may have differences and certain nuances, which should be remembered. So, for example, the brake caliper "Lacetti" caliper and in its design, both in principle and in the arrangement of the parts, differs significantly from the analogous unit installed, say, in a Toyota Land Cruiser. And since the faultless and faultless operation of this system is a vital factor for any vehicle, maintenance and repair of the rear brake caliper requires a high degree of preparation and appropriate qualification.
Dismantling and replacing the part with your own hands
However, with the urgent need to replace the rear brake caliper can be made and on their own. To do this, you will need to perform the following actions:
- under the front wheels you need to install chocks (brake shoe, building bricks or other objects);
- then use a jack to lift the rear of the car;
- for safety purposes, it will be necessary to place the stops under the rear of the car;
- then you can dismantle the corresponding wheel;
- further disconnect the manual brake actuator (if any);
- remove protective caps from the guides;
- Unscrew the guides with a hexagon, carefully remove the caliper.
An important point.If you need a complete removal of the parts, you will probably need to disconnect the brake hose. In order to prevent leakage of liquid, you should have at hand a piece of rubber, cellophane or a dense cloth, which plugs the hole of the hose. We should not forget about the need to connect it after installing a new element. Otherwise, the system will not work.
Periodicity of prevention and repair
Modern brake caliper is asufficiently strong and reliable device, failing and getting serious damage is relatively rare. Nevertheless, for safety reasons, it is recommended to carry out diagnostics of this important unit at least once every 6 months. And it is best to trust work of this type to qualified specialists. This, of course, entails certain financial costs, but in return guarantees security and can even save human lives!
So, we found out how the brake caliper of the car is arranged and how it can be diagnosed independently. Good luck!