1999 discovery II. My suspension holds fine running or not running for any length of time, but as soon as I add weight to the rear (rear passenger) or hit a big bump the air suspension drops all the way down. If I stop and hit the suspension raise button it just flashes at me and doesn't do anything. However after a couple of hours the suspension will decide to rise back up to normal height again.

I'm pretty sure it's not an air leak because it holds the suspension at the right height fine, even for days when the car is not running. I'm also pretty sure it's not the compressor because it sounds good and seems to work fine raising the car up, but as soon as a human gets in the back seats it lowers and gives me issues for several hours after the weight is gone.

Any ideas???

 

Might need to take it in to a dealer. Their computer (testbook) may need to be used to change something with the programing. A lot of people have problems with the air suspension and end up changing over to regular coil springs. If you do change to coil, you still have to take it in to have the computer ignore the self-leveling system, or else you end up with a warning light every time you drive on anything that isn't perfectly flat, paved road.

I've never worked on the air suspension, but I don't see how it could be anything other than a computer problem or a height sensor problem. You could try looking under the rear and see if there is anything physically wrong with either of the height sensors. If you're not getting a flashing auto level light when you drive, I kind of doubt it's a height sensor.

 

I agree that this sounds like a sensor problem.

 

Stop pushing the dash button when having problems, you are just loading up the ECU with soft faults.
If you want some help, send me your number and I'll call and walk you thru what to check, but as already mentioned, you will need to get the codes read, takes a special scanner to read them.

 

I am having the same issue with my 1999 Disco, however in my case, I can hear air hissing from the air spring after driving over bumpy Oahu roads. I am considering changing the air springs with parts from British Atlantic. Is this a job that a moderately mechanical person can do on his own and is the test book an absolute requirement? I ask because the LR dealership here wanted upward of $1K for air springs that cost $170 from BA and I'm sure the cost of hooking up the test book will be high as well.

 

Muncko...
My bags were leaking too. If you can find the leak in the air bag, your fix could be relatively simple.
I inflated them with the dash button.., took some soapy water, spray the bags down... And the leak showed itself...from under the "fold" in the bag at normal height, it became visible afteri inflating the suspension. I ordered my bags from Arnott at a cost of $265 (eBay) is one way to get them, or go directly to them.
Use the Rave CD and the instructions that come with them and should take about an hour or so per side to replace... Easy to do with jack stands.
I removed the old ones, put the new ones in, turned the ignition on and made sure all the doors are closed and it pumps itself back up. No test book needed if it is just a leaking bag. If it becomes electrical or a sensor issue....that could be another story.

 

Why would you want to replace the system because of leaking bags, why not replace them with some from Arnott and enjoy the ride you are used to?