8.3.2. Regulation of clearance
Cars of the E-class are equipped with the clearance regulator (a road gleam) which allows a back part of the car to keep to constants value of clearance irrespective of loading. Thus, even at full load or at the movement with a full luggage carrier and the trailer road performance of the car does not worsen that positively affects active safety. On the cars equipped with the clearance regulator, the oil pump of the regulator is installed directly behind the power steering pump. Sometimes the name "tandem pump" as both pumps are put in action from one shaft meets. The pump of the regulator of clearance pumps working liquid from a compensation tank and can create at the corresponding resistance pressure to 200 bars. Further working liquid under pressure arrives from the pump to pressure regulator located on a back suspension bracket. The regulator is connected to the stabilizer of a back suspension bracket — thus loading of the car is defined. Depending on it the regulator opens or closes the corresponding valves for working liquid.
The following working conditions of the regulator of clearance are possible:
1. Filling. At strong loading of the car the lever of the regulator moves to the top situation, and working liquid moves in accumulative tanks on depreciation racks. A back part of the car rises while the lever does not hold average position again. If loading is so big that the lever does not come back to a starting position, the safety valve limits pressure in racks at the level of 150 bars.
2. Discharge. In this case the lever of the regulator is in the lowermost situation. If a back part of the car is unloaded, working liquid comes back from racks to a tank, a back part of the car falls. In racks, however, pressure of 30 bars for damping function implementation remains.
3. Average situation. Working liquid almost without pressure arrives from the pump via the regulator to a tank.
Check of the regulator of clearance
SEQUENCE OF WORKS
1. Check the level of working liquid in a tank — it is in a motor compartment at the left and provides also the power steering. At normal loading of the car level has to be between the marks "MIN" and "MAX".
2. For a doliv use oil for system of a hydraulic actuator (take at the company station). Use the liquid specified on a tank: oil for system of the hydraulic actuator Zentralhydraulikoel (Nr. 000 989 20 03/10 for a one-liter container).
3. At regular falling of level of liquid in system check a tank, the pump, the regulator, accumulative tanks on racks, shock-absorbers. At the working engine it is simpler to find the place of a leakage.