Air Bag suspension question

[jsbihn]

So when the air bags usually go out, is it because of the compressor or the bag itself?

Just wondering if there is a way to replace the compression with something different so not to spend gobs of money replacing the compressor.

Also is there a way to put helper springs on so that the air ride is still there but the helper springs help it if it starts to sag out?

And lastly is there any write up or photos on what and how to do an air bag to spring swap?