Land Rover Repair: Rear air suspension, land rover discovery, land rover discovery ii

Question
In a Land Rover Discovery II we recently bought, the rear suspension (both sides) works very randomly. Sometimes it will stay up for 24 hours while parked, while other times it goes down immediately. The suspension usually stays up while driving, but does rarely drop while on the move, relifting at will. No leaks have shown in the bags, etc., and nothing appears on diagnostic tests. Any other possible solutions or just switch over to coil shocks?

Answer
If the suspension goes flat, it has leaks, right?  YOu just have not found them.

If the diagnostic tests have not revealed anything the choices are:
1) find a more skilled person to test it
2) wait till it gets worse
3) convert to coil springs.

Since almost any repair will cost more than the cost of coil conversion most people opt to convert rather than repair.