Mercedes of the S-class W202

1993-2000 of release

Repair and operation of the car

To understand why the shock-absorber is necessary, – try to do a bit of traveling without it...

In order that the car did not perceive all roughnesses on the road, in a suspension bracket of the car any elastic element is surely used. Usually применятеся spring. Besides a spring, the spring can be used, but it is already full antiquity. Other alternatives of a spring – a pneumosuspension bracket of "Citroën" or a hydropneumosuspension bracket of Rover which use the compressed gas. But we will return to a spring. At movement along the road the car begins to be shaken, and it is inadmissible. The main task of the shock-absorber also consists in extinguishing these fluctuations, or to damp.

All shock-absorbers work by such principle: in the cylinder of the shock-absorber there is a rod with the piston, which "goes" in oil. Oil during the operation of the shock-absorber flows through a special opening of the piston. It also creates the necessary resistance to the movement of a rod. Also in the shock-absorber there has to be a container (the compensatory camera) with the compressed gas (air or nitrogen). In the shock-absorber the piston goes and forces out surplus of liquid, forcing to contract gas.

When as gas air is used, this shock-absorber call hydraulic (the "Soviet" shock-absorbers SAAZ). The lack of air is that it at continuous jolting "makes foam oil", and at stronger jolting there can be bubbles of low pressure that considerably reduces overall performance of the shock-absorber.

Instead of air nitrogen is often used. Sometimes it is downloaded under low pressure in several atmospheres. Such shock-absorbers call gazonapolennny low pressure. But nitrogen under low pressure does not solve a cardinal problem of "oil foaming" and cavitation (that is formations of bubbles of low pressure).

Exit was found when the French engineer De Carbon pumped in the compensatory camera nitrogen under pressure of more than 20 atmospheres and separated nitrogen from oil laying piston which does not allow nitrogen and oil to contact among themselves. It removed a problem of foaming of oil and cavitation. Nitrogen under high pressure allows valves of the piston to work silently and quickly, and also creates additional effort on a rod. Such shock-absorbers work effectively and precisely.

Gas-filled shock-absorbers are not recommended to be used by small cars as the additional effort to a body rendered by such shock-absorbers is harmful to "crumbs".

Recently there were new developments. For example, Koni makes shock-absorbers with rigidity adjustment. Most "fancy" allows to do it directly of salon. Such "steepness" is put on the Maserati car. In turn BOGE developed system of automatic control of a road gleam (Nivomat system). Its sense that when the car is loaded, he "sinks" and it changes a road gleam (clearance). As soon as the car is loaded, fluctuations of wheels at the movement put the pump which is built in a shock-absorber design in action. This pump after several hundred meters restores a necessary road gleam. After unloading the car the pump is automatically adjusted at an old size of a road gleam.

The shock-absorber is that part of the car of which you do not think until until it breaks. As soon as the shock-absorber "was covered", we realize as without it it is bad and as with it it is good.

The car with idle shock-absorbers after journey of any hillock begins to be shaken dangerously, it is possible even to hook a belly on asphalt. The shock-absorber can and jam, then the car turns into "stool". If it occurred, then and it is clear to the baby – shock-absorbers should be changed or repaired.

But usually shock-absorbers wear out gradually and the driver of it does not notice. By estimates of the western experts, in Europe about 30% of cars are more senior than 5 years go with the damaged shock-absorbers. And what becomes in the CIS countries with our roads – in general it is unknown.

And shock-absorbers influence not only comfort, but also traffic safety. Here it is pertinent to give results of work of the independent research organization "Tuv Rheinland" which carried out expertize about influence of the shock-absorber on traffic safety.

When braking at a speed of 50 km/h on the dry road with one shock-absorber which is worn out for 50%, the brake way of the car increases by two meters. It is a lot of or a little – to judge to you. But as there are also not enough often these two meters for avoidance of the tragedy.

When the car with the shock-absorbers which are