Brakes

• we replace the brake pads
• we exchange shields
• we replace the brake shoes
• we replace the cylinders
• we clean the brake pads
• we clean the brake shoes

More information about the brakes:

The vehicle’s braking system is all the elements intended to stop the vehicle in motion (as well as keep it in place, e.g. on a slope).

According to the regulations, the car must be equipped with two braking systems:

• basic (working) – activated by foot by pressing the brake pedal. Braking takes place only when the brake is pressed (monostable system)
• additional (emergency; colloquially: manual) – this brake is mainly used as a parking brake, in order to protect the vehicle from driving away from the parking place. In the event of a failure of the service brake, it has the task of emergency braking the vehicle. The emergency brake is activated, depending on the solution, by hand or foot. It works from the moment it is turned on until it is turned off (bistable circuit)

The basic brake system in a passenger car most often works on the principle of a hydraulic press. The driver, pressing the brake pedal, pumps the incompressible fluid in the hydraulic system to the pistons in the wheel brakes.

The pistons in the front brakes have a larger surface area than the pistons in the rear brakes. Thanks to this, the braking force of the front wheels is greater than that of the rear wheels.

The biggest advantage of the hydraulic braking system is that the braking force is distributed evenly on the right and left wheels, i.e. the wheels of each axle are braked with the same force (which was not ensured by the previously used linkage systems).

The hydraulic brake is most often assisted by a power steering system powered by a vacuum from the engine intake system. If the engine stops, the power steering stops working. When the engine is switched off, the assistance does not work, but most often in a passenger car, the driver is still able to brake with the basic brake without assistance. It takes more strength but it is possible.

In light trailers, an overrun brake is sometimes used that creates a braking force on the wheels of the trailer when the trailer presses on the brake handle, which takes place when the car slows down.

Pneumatic braking systems are used in heavy trailers, trucks and trains. The air brake system maintains high pressure in the system.

The air brake brakes when the pressure drops. The pressure drop occurs when the driver applies the brake, which activates a pneumatic valve that reduces the pressure in the system and applies the wheel brakes.

A pneumatic pump (usually driven by the vehicle engine) is used to maintain the pressure in the brake system. The advantage of the pneumatic brake system is that after stopping the engine, the driver can still stop the vehicle and when the pneumatic lines break, the brake will immediately start working and stop the vehicle.

In a hydraulic system, two brake circuits are usually used. In the event of failure of one of them (e.g. as a result of breaking the brake line), the other is to enable emergency braking of the vehicle. Most often, one circuit brakes the front right wheel and the rear left wheel, and the other circuit brakes the other two wheels.

Often in simple systems (without ABS or traction control systems), a brake force equalizer is used to reduce the braking force of the rear wheels when the pressure on the rear wheels is lower.

One of the elements of the braking system is the master cylinder. It has two sections (two pistons in two separate cylinders) for two braking circuits. There is a container with brake fluid on the master cylinder. Brake pads wear down during braking.

The more the pads are worn, the more the pistons remain in the brake callipers. This, in turn, increases the capacity of the brake system and reduces the fluid level in the brake fluid reservoir. This is correct. The level of brake fluid in the reservoir drops as the pads wear.

The condition of the pads can be estimated based on the fluid level, provided that the fluid has not been replenished. In new cars, a fluid level sensor is used in the brake reservoir. This sensor activates the warning lamp.

If the light comes on while driving, but goes out from time to time, the pads are most likely badly worn and need to be replaced. The second possibility is that, for example, a piece of sheet metal lying on the road was dropped by the wheel and broke the brake hose. Then it remains to brake with one circuit and stop the vehicle in a safe place. Keep in mind that the low fluid level light is also often activated by applying the emergency brake.

Sometimes a special layer of lining is used in the blocks, which makes a loud squeak. This layer is placed in the last part of the cladding. This has the effect that worn pads squeak before the discs fail. The last sign that the pads need to be replaced is the noise made by the metal parts of the completely worn pads rubbing against the disc.