Before I order door lock parts....

[psaboic]

Ok,

I spent the better part of four hours today troubleshooting my door lock issues. I used my mity-vac vacuum pump and the following diagram which was a tremendous help.
http://ericandkat.com/mercedes/W123VacDoorLockDiag.WMF

All my hard plastic lines, check valves, and rubber connectors are fine (thank God) but I found three problems that I think caused my lock issues.

1. The PO appears to have tried to troubleshoot the issue before. I found the lock and unlock lines switched on both passenger doors (i.e, applying vacuum to the lock circuit would cause the door to unlock, and vice-versa) Fixed that issue.

2. The left rear door lock pod will not hold vacuum in either lock or unlock mode and needs replacing.

3. The fuel door lock pod will not hold vacuum.

4. Not sure if this is an issue or not. Is the Master vacuum switch in the drivers door supposed to act like the other lock pods, or does it simply switch vacuum from the vacuum pump depending on the lock position? When I applied vacuum to each orifice on the switch, it would hold vacuum until I moved the plunger manually, then it would quickly bleed off. However, the plunger never would move by itself with just vacuum applied. I'm thinking it is working correctly but would like to know for sure.

Bottom line is I need some parts. How hard is the fuel door lock pod to replace, and is it worth the effort? Also, I know I need a rear door vacuum pod, but based on the above, do you think I need a driver door master switch as well.

Many thanks,

Glenn