Land Rover Repair: 2001 Disco II rear air suspension, compressor pumps, isolation valves


Question
Do you think the after market air springs are as good as the genuine Land Rover air springs? Is there an on line schematic of how the Air spring system is layed out? I heard there was a chamber or reservoir that held air for quick inflation/deflation. I guess thats not true. Thanks for all your help Dennis.
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-----Question-----
I recently purchased a 2001 Disco II with SLS. It's been fine for a month, but the last few mornings it has been sitting all the way down on the rear. Are the 2 rear air springs isolated from each other? (If one has a leak the other will stay up?) It seems to be sitting down on both the left and right. Do they use the same air chamber for inflating both. If so where is the "T" connector or split? As soon as I start the truck. It raises immediately so the air reservoir doesn't seem to be losing air. Does this sound like it could be a leaking shock or associated connectors? Thanks for your help.
-----Answer-----
This is most likely worn out airsprings.  They are controlled by separate valves, so if one leaks the other will still have air, but it will be supporting the full weight of the rear of the truck- so it will sit lower and have a higher pressure, which may cause it to leak as well.  There is no resivoir, the pump goes directly into the springs.  Since it raises quckly your pump is probably still good.  New springs are the first step.

Answer
The after market springs I carry have a lifetime warranty, they are definitely better in quality, they also have design improvements to ease installation and durability.  The p38 system has an air tank, the DII does not have an air tank, the compressor pumps directly into the springs through 2 isolation valves.  I don't know anywhere online that has the diagram but the LR workshop manual (rave CD) has a diagram and description of operations.