This system, common in older cars, uses hydraulics or air springs to keep the car's ride height consistent regardless of load. Over time, this system can fail due to several reasons:
* Leaking shocks or struts: The most common culprit. Leaks cause the system to lose pressure, leading to the car sagging under load. Without the pressure to compensate, the adjustment you felt is gone because the system isn't functioning.
* Failed air compressor (if air suspension): If your LeSabre uses an air suspension system (less common but possible), the compressor that inflates the air springs might have failed.
* Worn or damaged self-leveling components: Various components within the self-leveling system, like valves, sensors, or the accumulator, could be worn, damaged, or corroded. This would prevent proper pressure regulation.
* Low hydraulic fluid (if hydraulic suspension): The hydraulic fluid level might be low, preventing the system from functioning correctly.
* Electrical issues: Faulty sensors or wiring related to the self-leveling system can prevent it from working.
Since the adjustment no longer happens, it strongly suggests a failure in the self-leveling suspension system. You should have a mechanic inspect the rear suspension components, specifically focusing on the shocks/struts, and if applicable, the air compressor or hydraulic system for leaks or other damage. They can diagnose the specific problem and advise on repairs.
