The first few days, the compressor just ran longer when I got into the car, then after a few days, the notification area inside the speedometer gave a red notice something like " do not drive car, car too low" and the compressor ran for a minute or 2 and the warning went out. I do figure that in a few more days it probably would not pump up at all and all that pumping could cause the compressor to fail, adding another 3-500.00 to the repair bill. I was right on top of it and by the time that message showed up, the appointment to fix it was the next day. On only the drivers side, which was the first to go, I heard a pssssst when I hit the speed bumps where I live, and took it to the shop immediately, and they diagnosed it and ordered the strut. Hope that helps. It is one of the repairs that just sucks you in, no alternatives, and I only use MB parts on the car. Local shop warranties work and parts for 2 years on MB parts in their repairs.