Features of brake system diagnostics
The key to a quality brake system repair is a professional and accurate diagnosis of the brake system, which includes a number of tests and measurement of the main performance indicators. A decision can then be made as to whether a partial or complete (comprehensive) overhaul of the system is required.
The principle of a car's brake system
In modern cars there are few types of braking systems: working, reserve and parking. The first of these functions while driving. The driver uses it all the time. When he/she applies the brake pedal. The second, which also comes out of the name, is used in case of failure of the working braking system. It makes it possible to carry out a complete stop of the auto. The third – it is, in fact, a handbrake. It allows you to keep the car in an equilibrium static state on inclined surfaces.
When the car is moving, the wheel rotates and with it the brake disc. If necessary, it is the brake disc that reduces the speed of the wheel. It performs this function by means of brake pads, which squeeze the top of the rotating disc on both sides, thereby reducing the rotational speed through friction. In turn, the pads are actuated by pistons that are placed in brake cylinders. When brake fluid is injected into these cylinders, it acts on the pistons and they squeeze the pads, which gradually reduce the speed or stop the wheel from rotating through the brake disc.
The most common causes of brake system failure:
- the presence and installation of poor quality components;
- failure or end of service life of one or more components of the system (brake pads, their pads, brake discs, cylinders, brake pedal return spring, caliper, etc.);
- leakage or contamination of brake fluid or air in it;
- regular violation of the rules of operation of the braking system;
- various external factors.
When should diagnostics be carried out?
Diagnostics of the brake system is carried out as part of routine maintenance or if there are characteristic signs of brake failure:
- extraneous sounds and squeaks in the brake system components;
- the presence of uneven wear of brake pads;
- driving the car to one side when pressing the brake pedal;
- heating of brake drums;
- «beating» of the steering wheel when the car brakes;
- slumping of the brake pedal when the brake pedal is depressed;
- breaks and other damage to brake hoses;
- increased vibration of the car during the braking process, etc.
Brake system diagnostics at the service station
The procedure of brake system diagnostics in a specialised car service centre is carried out on a test bench. The primary stage of the procedure includes checking the performance of brakes on each of the wheels, measuring the working pressure in the brake system and other indicators (rolling resistance, force on the pedal and brake lever, braking efficiency, ovality of discs, difference in the level of braking force between the wheels of one axle, misalignment of the brake system drum, etc.).
The technician then performs a visual inspection of the mechanism to check the following factors:
- the presence of brake fluid leaks
- level of wear of brake pads on the wheels;
- the condition of brake discs, calipers, their guides and brake hoses;
- the level of wear of brake pads on wheels;
- Besides the bench, there is a road diagnostic method. This is a test of the mechanism on the road.
As a result of the diagnostic procedure, some remedial work may be required to restore the brake system to its previous performance. In particular, the following may need to be replaced:
Brakes may need to be replaced.
- brake cylinders;
- brake fluid;
- handbrake cable;
- brake pads or discs;
- brake lines, springs or hoses
In addition to replacing parts, it may be necessary to flush and dry the pads, adjust the brake booster or brake pedal, remove a stuck piston in the cylinder, or clean or adjust other brake components.
Besides replacing parts, it may be necessary to flush and dry the pads, adjust the brake booster or brake pedal, remove a stuck piston in the cylinder, or clean or adjust other brake components.
After the restoration work is carried out, the brake system is pumped (to pump out the air, otherwise the brakes will not function properly). Also on our site you can find equipment for diagnostics of car air conditioners.
Brake system pumping (to pump out the air, otherwise the brakes will not function properly).
