The vacuum system on earlier Mercedes® models controls several functions, including the locking system, engine shutoff (on diesels), and several aspects of the climate control system. Chasing down a vacuum leak in the system is not impossible, but you will need a vacuum tester (our part number 58-013). We offer replacement door, tailgate, gas flap, and trunk lock vacuum valves, repair hose and diaphragms, vacuum fittings, check valves, and more to get your system operating correctly