1983 300CD

The dual chamber vacuum element that locks the fuel door is no longer made and not available anywhere.

Good news! The single element unit from 1981 300CD and earlier will fit (123 800 01 75). My 1983 300CD chassis is double drilled to accept either actuator.


You will connect the rubber T on the yellow/red line normally, and remove the T on the yellow/green line and replace it with a 3 inch piece of vacuum line (bypassing the vacuum element). Also, you will need to transfer over the two screws, washer and spring from the old element.


No parts house, not even Mercedes-Benz, knows of this double drilling of the chassis on the 1983 model year. I would be very interested to know what other model years are double drilled on the 123 coupes.

Here's how to tell. Get a flashlight and get into the trunk, or at least lean as far forward as possible. Your head will be near the front of the trunk. Look right 90 degrees, just forward of the big spring. What do you see? If you see three holes and a short horizontal slot, it's double drilled.

The left hole and horizontal slot hold the bracket which holds the old style vacuum element. The two right hand holes secure the new style element without needing a bracket.

Please post your model year and what drilling you have. Maybe after we collect some data, we can get this in the DIY section and notify the parts houses.

Thanks.