The ABC system from Mercedes Benz contains various valves. The valve blocks (control valves) located in the front and rear of the vehicle have a dual function. One part of the valve block allows fluid to enter the strut, to close off the strut, or to leave the strut. When the ABC system is active, this control valve is operating and able to control the 3 different height levels during driving. The other part of the valve locks the struts at their current fluid levels when the ABC system is not in operation (parked). When the car is not running, parked or the transmission is not in gear, this valve is closed. Cars having difficulty to maintain height when driving and/or when parked could have an internally leaking valve block, it will be unable to hold the pressure at the struts. In addition to the front and rear control valves in the car, there is a pressure limiting valve and a suction valve that controls the oil supply to the pump. In the overview below you can see which reconditioned valves we supply.