Cadillac Repair: rear suspension, rear struts, minuits

Question
I have a 1999 Eldorado ETC. My problem is when I hit bumps in the road, the rear end wants to jump around. Everything appears to be working with the shock system. I checked the height sensor, it works. There is air in the shocks. But, the shocks are empty by morning. They do pump up when I turn the car on. I assume they stay pumped up while I'm driving the car. Is that a wrong assumption? Also, there is no codes. Where do I go from here?

Answer
Hi Ancil,

       If your Eldo has over 100,000 miles it could be time for new struts.

       What I would do is drive your car around for 5 minuits to allow the air struts to pump up. Then on a level surface like your driveway or parking lot get out and bounce the RR, LR, RF and then LF corners of the car with the engine still running 2 times and then stop. If the rear end continues to bounce more than 2 times after you stop look at the strut where the shiny rod comes out and see if oil is also leaking out. If it is then replaceing the 2 rear struts should cure your problem. Even if there isn't any oil leaking the strut can still be bad because the internal seal is worn and oil is getting past it causeing the strut to move freely.

    You could have 2 problems in that if the air completely leaks out of the strut so that there is more than 1" differance between the ride height and the resting height then the airbags, lines, pump and height sensor need to be tested for leaks or propper operation.  

    Some of those things you could check yourself. Otherwise your mechanic will need to give it the once over to see where the problem lies. Hopefully I have been of some help. Bill