dhac1990

Had an independent shop replace the left rear air shock with used shock and every thing was ok the first couple of days but now sometimes when the car is turned off the suspension will drop and it's never the same. Sometimes just left rear, some times both rear shocks and you can hear it leak like it's dumping the air out. It can stay up for days at a time and then one turn of the key it will dump the air. Any idea's where to look? Thanks