strange eas fault

:welcome2:my 1998 4.6 has a strange eas fault
when parked up it lowers right down on the back end both sides and the front end stays up:doh:

rises from access to full height in about 8-10 seconds,has a recon compressor ,no leaks on air bags-have by passed valve block and inflated them manually left for two days and didnt drop so cant be the bags or air lines, new inlet and exhaust filters fitted
looked to see if any faults are stored with faultmate msv 2 - no faults
under normal operation pump runs for quite a while shuts of for 10 seconds and comes back on, and so on and so on.
only things i havent looked at is valve block and valve block driver
any ideas

Well the air has to be going somewhere. If the airbags don't leak, then the fault has to be in the valve block or driver. Try freezing the suspension by leaving the tailgate open if it is in secure parking, otherwise remove the relay under the passenger seat which will do the same. If it still drops, then I would say it has to be the valve block. If it doesn't drop then could be the driver pack or ECU. As an outside chance it could be a height sensor giving duff readings, try removing the connectors to the sensors, cleaning and replacing.

could be a bad sensor