Help! Air suspension

[vglover]

The right rear of my 04 Hummer is 4-6 inches lower than the left. I have in the past 2 months replaced the compressor, both air bags, both leveling sensors and a relay switch and the problem remains. The dealer doesn't know what is wrong and I have spent over $3,000.00 trying to fix it. The truck has 36,000 miles on it, almost brand new! Any suggestions as to what else could be wrong? I am taking back to the dealer tomorrow.