suave

Hi, I own a Xantia 2.0 of 1999 model. Recently, it has started shaking up & down even on small bumps on the road. The local car mechanic thought it can be due to lack of hydraulic fuel-that resulted into malfunctioning of the suspension system. I added the LHM fuel, 1 liter, but the problem is same. What you guys think can be the real issue and how can I fix it. Thanks!