So, here's my first question:

The previous owner of my W140 300SEL recently replaced central locking vacuum pump.

Now it is damaged again. It showed up, that the pump itself was filled with oil, which had overloaded the pump, causing the rotor of the pump mechanism to break.

Tracing the vacuum distribution, i appears that the oil comes via the vaccum distributor block from two valves in the left of the engine room. One valve has black/green line coming from A/T (upshift delay switchover valve), and the other valve has black/red line coming from A/T. The oil comes from the black/red line.

I assume that the oil is transmission fluid, which is leaking through the vacuum actuator connected to the black/red line.

But I can not see in the diagrams, what this actuator is doing, and how I can access it for replacement.

Any help?

PS: I will wait to replace the vacuum pump until the leak has been cured and the vacuum system cleaned.

Checks the vacuum line on the transmission modulator for oil, the modulator could be leak transmission fluid.

Yes, so i've heard, which is also why I looked for a path to A/T.

But the modulator has its own vacuum outlet from the manifold, i.e. it does not come via the vacuum distribution block. And the modulator vacuum line does not seem to have oil in it. Anyway, it would be against the stream to pass oil from one vacuum outlet on the manifold to another.

The vacuum distribution block has a non-return branch connected to A/T vacuum reservoir and to the two switchover valves mentioned. And there is clear traces of oil in the line leading to the valves and in the black/red line leading from one valve to the A/T. I can only see that it goes to somewhere on top of the A/T but not exactly where.

So, does anyone know what it does, and how I replace the leaking part (whatever it is)?