Hi my wifes recently acquired Discovery2 td5 at 84000km was resting on the bumpstops after being parked for the day and hasn't risen since.
System never had a fault or any sign of lowering it self.
I am a mechanic just never worked on Land Rovers before.

My initial inspection based on posts read was to check the compressor
if vehicle is started compressor runs for approx 45secs then shuts off
checked lines bags and compressor for leaks none.

Removed lines numbered 20 and 22(could be wrong about numbers left bag and right bag however) from "check valve"/Relay block which released what little air was left in each bag .

Removed lines to and from compressor and engaged the raise level switch, line at rear is providing suction and two to front 3/8 had pressure and 1/4 line to valve had a pulsing kind of pressure.

Whats the chance of the relay/valve block being stuck shut tested connectors output from both is 3.67v

Also noticed the compressor runs for a very short time when engaged manually or auto when vehicle is started

"Ruled out" electrical faults due to fault light never once being displayed
and air bags because they both failed the same day and never once heard a hiss or had a leveling problem

How long should the compressor run for when started
from 0psi to vehicle fully raised.
Also the 3/8 outlet hose from the compressor where the heck does it go traced it to the rear and up behind the bumper

I really hope this compressor hasn't given up the ghost sigh......

This is very frustrating I like driving the vehicle but reliability seems to be marginal