1981 to 1991 W126 Chassis Sedan Vacuum Door Lock Troubleshooting and Repair - On Demand Video Manual
W126 vacuum door locks on the 1981 to 1991 380SE 380SEL 300SD 500SEL 300SDL 420SEL 300SE, 300SEL 560SEL 350SD and 350SDL are prone to problems. For starters the systems are getting old, and with age comes common leaks and failed actuators.