Air suspension

Looking for some help regarding my discovery 2 air suspension problem.
My driver side suspension bag over inflated and would not go down, I checked and found that the height sensor mounts had failed. I ordered a replacement sensor so I released the air via the compressor fitting to level off until my part arrived . Then the full back end dropped overnight . The new sensor arrived and I fitted after reading up on this forum, started up the car and the suspension bag did not over inflate but when I turned off the engine the car dropped down at the driver side at the back on to the stops !!!!!
What do I need to do know ? Any help would be great.

I take it you disconnected the battery before fitting the height sensor? If you did I would suggest there is a problem with the air bag itself.

As it happened before you removed the sensor I would suggest the airbag is damaged/leaking or the pipe is leaking where you disconnected it from the compressor. Soapy water in a spray bottle should assist in finding small leaks.

Conventional thinking would suggest that if the suspension over inflates it's probably due to one or both ride height sensors being at fault. If the suspension drops then a faulty bag could be indicated.
The airbags are just a rubber tube filled wih compressed air, and you wouldn't expect the other four (or five) compressed air filled rubber tubes to last the life of the vehicle. Most users of air suspension consider them to be service replacement items and change them every five years or so.

A couple of points to note, mainly found through members bad experiences:-

• A faulty bag will never leak while you're searching for the fault
  
• Just when you've convinced yourself that it's not the bags, it'll be the bags!

I did not disconnect the battery when swapping over the plug on the sensor . I read a few posts and there was not a straight answer regarding the battery disconnection. I will have a test with the soapy water and check the fitting at the compressor .

Although there seems to be no "straight answer" as you call it, it does make sense to disconnect the battery when you do that job.

Anyway, now that the sensor has been changed, and it's advisable to change both sensors at the same time, you are now in the position of being unsure whether the system has lost its calibration.

To check it and reset it if it's needed you're going to need a code reader compatible with the Disco 2 diagnostics.

Just a update I checked the air bag with soapy water and no leaks , I then check the compressor fittings and tightened up , I then tried starting the car and stopping then raised and lowered .
And it did not drop again as before and the level looks out by about 15mm to each side not to bad .I Think it could have been leaking at the fitting . I tested on the road and ok and also two and a half days later it is ok. Even towed my boat and it was fine.
Cheers for the input