Hi,
I recently bought a '79 240D, which I love and think is a great car, but one thing that irks me is that it won't lock. I read in the shop manual that the locks are controlled by a vacuum pump (in addition to the brake pedal), and I am thinking that it is shot because the locks are stuck up and braking is hard as well. Am I on the right track here, and is it too difficult to replace yourself?

Also, I need to know if I am missing a door key, if anyone has the same model, does the ignition key work in the door or do you have a separate key for the door lock?

Thanks,
Eric

The early diaphram vacuum pumps can be easily repaired. Remove the front cover and replace the diagram.

Originally your car had a master key that would work all locks and a valet key which only worked the doors and the ignition but not the trunk or glovebox. The difference in keys was in the blanks not the tumbler code. In other words, a valet key could be cut off a master by doing it on a different blank that had a different horizontal groove.

As locks wear out they can be purchased in a workshop version (with key) or in a coded condition (from the chassis number). The occurance of ignition lock failure causes many to be replaced with workshop versions as it used to take a couple weeks to get a coded version. It is now almost an overnight deel so we only put workshop versions in as loaners.