88 300sel now hissing underneath,lost height

[jensbenz]

Have checked my fluid, so there is not a leak. Have been reading about
the self levelling but upon ringing for prices am confused. Somebody called the part a pressure reservoir,another an aircell and another an accumulator.Im in Australia so does anyone know whether they are all talking about the same part.? Could the air be coming from the damper
shocks? The back goes up when I start the car, but loses height and the
ride is as hard as concrete.Cant work out where the noise is exactly coming from but seems to be from the shocks? Love this car so need fixed asap!!!!