Hello Forum.... I have a 94 E420 that will Not drop down rear headrest from dash switch. I have tried replacing dash switch And replacing valve under rear passenger seat behind driver; still NO release. The valve under seat had NO vacuum when i removed hoses. I am not able to get rear seat back "off" with headrest in upright position (to replace rear seat back and bottom). Dash release switch And vacuum valve are 'working' But right now i just need to get headrest 'Down' to complete my rear seat swap...Then i will attempt to diagnose and repair 'lack of vacuum issue'. By the way; vacuum system for doors and trunk lock/unlock works flawlessly. THANKS; in advance -for All help sent my way ............kevin