Low rear suspension on my 1999 Cadillac DeVille

The pump is back under the rear of car, but by now, the shocks are sure to be leaking, which causes the pump to run too much burning it up. Best fix is to replace rear shocks with coils and dump the self leveling feature, or prepare to pay big bucks to replace most components.

rear shocks and lines for leaks, does air pump run? test for low
pump output, test height sensor on r/r control arm

HAVE VECHICLE CODE SCAN,SOUND LIKE YOU HAVE PROBLEMS WITH ABS BRAKES AND THE TRACTION CONTROL,SEEM LIKE YOUR AIR SHOCKS ELC HEIGHT SENSOR COULD BE BAD CAUSING AIR SHOCKS TO OVER EXTEND CAUSING CAR TO RAISE HIGH ON BACK END.WHICH COULD BE THE CAUSE OF ABS AND TRACTION LIGHT TO COME ON, TO FIX THIS PROBLEM HAVE CAR CODE SCAN AND YOU CAN FIND OUT WHAT CAUSING THE ABS AND TRAC LIGHT TO TURN ON.

Does you caddy have air suspension? Your going to have to replace the rear coil springs or (Air shocks) if you have them.

your rear air suspension bags are leaking, u will need to have them replaced, this job requires a service factory manal and tha proper safety procedures be followed, so it is best left to an expert.

There is an air compressor mountedmabove the rear suspension. The fuse for the air ride suspension is located behind the trunk rear trim panel. There is a level sensor on the rear control arm. If fuse is good, check for power at plug feeding compressor, compressor failure common. With suspesion at low position, sensor should send power to compressor. if no power suspect height sensor. Check relay for power and operation although failure rare.

You may have a leak in the rear air bags or the compressor for the air bags is not working,listen when you turn on the key to see if you can hear the compressor run ,if you do then likely the bags,if not then likely the compressor.

Up, as in suspension? The leveling valve linkage may have come loose and the suspension has over inflated. The valve should be above the rear axle

Check to see if the lever is connected to the rear suspension still. Look for a small rod disconnected. If not remove the rod and move it to lower the car.

you may want to buy regular heavy duty shocks and put on the car to raise the back up high enough to do what you are trying to do.