1990-1992 of release
Repair and car operation
+ Nissan Primera brand Cars
+ Current leaving and service
+ cooling and heating Systems
+ the Power supply system and production of the fulfilled gases
+ System of electric equipment of the engine
+ Manual transmission, differential and main transfer
+ Automatic transmission
+ Coupling and power shafts
- Brake system
Back disk brakes
Main brake cylinder
Pumping of brakes
Adjustment of brakes
Anti-blocking system (ABS)
+ Suspension bracket and steering
+ Onboard electric equipment
Anti-blocking system (ABS)
Hydraulic contour of anti-blocking system (ABS)
In general, it is not meaningful to describe a principle of work of ABS system in this management, however you will better understand your system if will know how it works.
Usually cars with ABS have disk brakes on back wheels. Affairs and on the Primera models also are, i.e. only cars with the engine of 2.0 l can serially or be equipped with ABS system at will.
The determinant of safety of ABS system — is ability to prevent blocking of wheels at sharp braking at the expense of what the car remains operated. Also at emergency braking there is a chance, to go round an obstacle. However it is not necessary to believe that the ABS system is capable to work wonders. If physical borders of system are exceeded, i.e. speed is too high, even cars with ABS can have an accident.
Four sensors of speed of wheels which are established in rotary fists or holders of back naves, trace independently from each other number of turns of each wheel. On illustrations Adjusting position of the sensor of number of turns of forward wheels and Adjusting position of the sensor of number of turns of back wheels is shown, where sensors of lobbies and back wheels are located. The microprocessor accepts signals of number of turns and reveals anomalies of rather put parameters. Thanks to this process brake pressure in the corresponding wheel for only a few seconds decreases or increases from 4 to 10 times, much quicker, than at so-called pulse braking by a brake pedal, besides adjustment on each wheel is carried out separately, instead of on all wheels at the same time as it occurs at work as a brake pedal on the cars which do not have ABS. In a back brake contour there are two valves of adjustment of pressure of braking sensitive to loading which prevent further danger of blocking of wheels, especially, if the car is loaded slightly.
Adjusting position of the sensor of number of turns of forward wheels
Adjusting position of the sensor of number of turns of back wheels
Two hydrovalves precisely distribute demanded brake pressure on forward wheels depending on coupling with the road. Two other adjusting valves operate back brakes. In this case the electronic control system reacts to the first wheel inclined to blocking. At optimum braking the car remains operated, course stability and the car is supported it is possible to keep control. At speed below 15 km/h the system does not work. On an illustration the schematic image of system thanks to which it is possible to orient in an arrangement of elements is shown.
Something it is necessary to tell about the hydraulic pump and a pulsing damper (7) and (8). The pump submits liquid to a damper of pulsations and reduces pressure in supports. The clown has the pump. When the pump through the clown wrings out the piston aside, liquid from a broad tank moves in a damper, inlet and final openings, and the valves connected to them thus open. The piston on other party remains in the situation, i.e. inlet and final valves on this party remain closed. Thus valves operate a devastation and system filling. The damper of pulsations accumulates brake liquid under a high pressure and allows it to come back to the main brake cylinder slowly.
So the ABS system provides to you additional safety.
It is not recommended to make any works on system independently. In a workshop it will make better. However on the car works which influence ABS, for example, pumping of brakes are always carried out. Therefore at all works on brake system it is necessary to follow the following instructions:
Carefully clear all connections and area round them before them to weaken.
The removed details to display on a pure surface and to cover with a film or a white paper. Do not use fleecy rags.
Open elements of system to cover or stop up, if repair is made not at once. Especially it belongs to works in the open air.
Establish only absolutely pure details. At all do not use detail which were stored very long.
It is very tempting to use the compressor of the compressed air which is connected to a lighter nest, for cleaning of details. Not to do at all it if system connections are opened.
After ignition inclusion the hydraulic pump within 60 seconds creates working pressure in system. The control lamp of ABS lights up for 2-20 seconds, depending on what pressure in system. The electronic monitor checks separate components. If any malfunctions are thus found, the system works as usual brake system without ABS. If it occurs, i.e. the control lamp continues to burn, it is necessary to address in a workshop. In a workshop by means of special devices can carry out diagnostics of malfunctions which can have the electric or hydraulic nature.