I have an 81 240d with vacuum door locks and one door will not go locked when the others do. Would I replace the vacuum switch in that door or possible it could be elsewhere? Please assist !!!

Chances are good that one, or both of the diaphrams for that actuator are shot. Check the condition fo the vacuum lines into the door first as one or both may be cracked. If the actuator is bad, Steve Brotherton has suggested replacing all three (pass front and both rears), as the added stress of a working system may blow (or suck) out the remaining old actuators.

I didn't listen, only changed the bad ones. Sure as I sit here, in 6 months I replaced the third one.

Easy to test with a hand held vacuum pump. Just be sure to isolate the system by plugging the line to the reserviour. Once that is done, you can cycle the locks in approximately 3 pumps.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Can the diaphrams be repaired or replaced by themselves or do you need to replace the entire unit?

On some acutators you can simply replace the rubbers, other actuators the rubbers aparently cannot be replaced. On my 108, I can replace the rubbers and as such suggested to a friend that he could do the same on his 1985 123. NOT. He had to replace the entire actuator.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Thanks that helps a lot !!! What a cool web site for cool cars !!!

Mike, as always, is correct about having to replace the entire actuator on the 123 cars. The good news, though, is that they aren't very expensive.

Follow Mike's suggestion and check them before replacing them. I guess I've had better luck, my '84 123 car with over 500,000 miles needed the gas flap one replaced. It's the only one that's ever been replaced and the system is still tight.

Mike is just spoiled with his swanky, big bodied car, they were built differently in many ways. The 123 was built for much less money, so some of the pieces on them are made like a dollar watch. His 4.5 is the opposite, it's constructed like a piece of manufacturing machinery, not the weight, just the methods of construction.

Good luck,