Land Rover Repair: self leveling system, rear end dropping, airsprings, rear spring

Question
My 2001 disco's rear end on the passenger side drops down almost to the top of the tire after the engine is turned off. This doesn't happen everytime but quite often. It does correct itself when the vehicle is started and all the doors are closed. What's causing it? How can this be fixed? Thanks Gary~

Answer
This is most likely a leaky rear spring, and if one is leaking the other is about to start leaking.  

You can replace the springs, or if you do not like the leveling feature you can remove the airsprings and replace them with standard coil springs.