I have an 03 h2 with about 60K miles. Few days ago I woke up and the pass rear was low. started truck and it reinflated and held as it should. then few days ago woke up to find both rear bags deflated. Started truck, pump does NOT turn on to reinflate. At that point I assumed that my bags had a leak, and that the pump had burned out keeping them inflated over the past few days. in order to avoid replacing the pump and bags and lines I ordered a set of springs and isolators from GM Parts Direct.

Heres where it gets interesting. I moved the truck the other day to allow me access to another car, and just out of curiosity i turned on the switch in the back for the tire inflator. To my suprise it turned on and built pressure. So this leads me to beleive that the pump is not bad at all. What could be the culprit here.

 

Different components of the air suspension attached.