Based thread title, I thought I would add to this one rather than start a new thread.
Most of the time my EAS seems to hold height overnight within about an inch . . Unless I park it backwards on the drive, or on slope at work. . . In either case if the rear is lower than front, the rear seems to drop to the bump stops within about an hour. If the front is lower, then the car stays up & level.
Before somebody mentions "self-levelling", I have a relay fitted that completely removes power to the EAS system when the Ignition is switched off . . . so no clicking valves, timers, etc.
Strange eh ?
Pete
Cannot be other than a leak then.