Hi all, I have read most posts about the rear sagging and how to's for diagnosis. Many good posts. All helpful, but no solution for me. So, hear we go. The 1998 expedition 4X4 has the body on the rear bump stops. rear Bags will not inflate. Compressor comes on. Solenoid under drivers door gets voltage and air passes through. Solenoid on air bag gets voltage. air is coming out of line at air bag when the line is removed. Hook everything back up and no inflation. I would think it must be the air bag. But, no hissing of air when the air line is attached. If it were the air bag, why would both fail at the same time? If the solenoid at the air bag failed, why both sides at the same time? The height sensor function correctly, ie, can remove from post and by moving up and down, turn compressor on/off. Since I have no experience with this system, I cannot say that the air pressure is correct, other than to say I thought it would feel higher. Could the problem be that the compressor is not giving enough pressure? Must it be the (both) air bags? Any suggestions? Thanks for any help.