R129 central locking

[Diversion]

Ohh do I hate this car ......

1993 300sl

I believe the pump has died, it is out of the car and will get repaired or replaced.

I have 6 vacuum hoses to the pump. Using a large syringe I have worked out.
Two hoses run forward.
One does Both door storage pockets and arm rest storage.
The other one has pressure but doesn’t do anything- I assume not enough pressure. What does it do ?

3 run backwards
1 does the boot lock
The other two run to the near side of the car but where ?

1 does the fuel filler cap.

I will test for leaks b fore refitting a new pump.

There is a unit in the engine bay under the cover at the back on the near side. Does this have any effect on the central locking ?

I will buy a vacuum pump to see if with sufficient vacuum I can get some reaction from the doors.

Thanks

[PositronicRay]

If you join benzworld and post on the 129 section someone will post up a colour coded schematic .

The block under behind the bulkhead powers the ventilation flaps, it uses engine vacuum, but I think its aided and abetted by the vacuum pump.

If you get a leak the vacuum pump can burn itself out.

[Diversion]

Thanks for that.

One of the other hoses goes to the Vacuum block in the engine bay.

The other two control the doors - i think these two are causing the problem.

[PositronicRay]

The yanks use a mityvac to diagnose, not seen them here. I suppose if you fit the new pump an it doesn't cut off smartly, then you could block one line at a time until you find the leak.

Mine had a pump repaired, but before my ownership so no idea what was actually wrong or done to it.