Air suspension on DiscoII - real teaser

Hi Folks,
read many (if not all) of the posted and the definative guide on the Air suspension problems - causes and "cures" - I have an intermitant fault - in that driver side rear deflates when engine off - but not every time - for example - if I find it saging at back right - start engine , it re-inflates and does not go down again,sometimes for days - If I then drive short distance - sometime is will have dropped again after engine off - in less than 20mins - Can't find a leak, sourced new valve block and put in and again today the blessed thing does it again - sags right rear.... Any Ideas? is there another solinoid or other value in the set up that I am not aware of? what else could cause this intermitant behaviour, Electrical fault?? Do the SLS operate on the vlaues when Engine is off...?

any help greatfully recieved
thanks
confused of Margate

Ok, soapy water approach still showing no leak - thought.... if car drops 20mm after engine off as designed by Landrover. This drp must be controlled by the SLS units by an electrical feedback mechanism. If there is a fault in the feedback loop, it could be possible that the "stop letting air out" signal never gets sent, hence the drop on the rear right onto the bushes.... Is my thinking flawed ?? anyone?

hi derick the fault lies within the air bag its self which is leaking depends in which angle you park it as to how quick it goes down sometimes it may not go down replace the bag problem solved reguards john