Cadillac Repair: air suspension, air struts, rear struts

Question
I have a 91 4.9L Sedan DeVille. I Just replaced the rear air struts with after market replacements. The air pump kicked into high gear and I believe overinflated the shocks. How do I soften the ride? My Haynes manual mentions an exhaust solenoid in the head of the compressor, and a ride height sensor, but tells me to take it to dealer. (I hate it when it tells me to do that!) Any suggestions?  

Answer
Hi Gary, If the rear struts are over inflated then the rear of the car will be higher than normal and that will confirm the diagnosis. Otherwise maybe you bought struts that will give a firmer ride than you want if the Caddy is sitting level and not jacked up.  

    The way to test the level ride system is to get the rear of the vehicle safely up in the air on jack stands and locate the height sensor which is located on the LR lower control arm. Make sure the link is still attached to the sensor and arm. If broken you can get a new link or fashion one out of a coat hanger. Then remove the link end from the arm and let all the air out of the struts by removeing an airtube. Reinstall the tube and raise the arm on the height sensor. After aprox. 30 seconds the compressor should turn on and the strut start to inflate. Let it pump up some and then lower the arm so the sensor tells the compressor the struts are full and after aprox. 30 seconds the struts should start to deflate. If they don't then the problem could be with the height sensor, the exhaust solinoid inside the level ride compressor houseing or wireing in between.

    In my experriance the height sensor is the part that fails more often but I have also replaced compressors for this problem also. The parts will be expensive so I would recommend useing used parts from a auto recycler/junk yard. Sounds like you will need a better shop manual and if you go to www.alldata.com you can get the same repair info the shops use and they should have the repair info there to help diagnose this with wireing diagrams and testing procedures. Otherwise if it isn't in their info they have a library where they look it up and fax the info.

   Hope that helps. Bill