W116, BENZ AID - COMMON QUESTIONS AND ANSWERS

I have a '71 220D with a mystery vacuum tap on the main line between vacuum pump and power brake booster.
It's unconnected, and there's also a disconnected hard line up by the firewall, but it doesn't have the length to connect to the brake-line tap. (These are the only vacuum fittings on the car.) That line is split by some sort of check valve or diaphragm/filter, and it disappears under the driver's side fender, right under the windshield corner. It's green, and it doesn't seem to reappear under the dash.
I thought at first it had something to do with the windshield-washer pump, but that's foot-operated, and I've successfully reconnected that.
Any idea on what the mystery line/tap is? I've got some MercedesSource hard line and fittings to reconnect things, but how and what?

I need to rebuild the injectors on my 1979 300TD, and I have a set of Monarks that I ordered here. I have access to a pop-tester and a shim kit.

I asked my mechanic about obtaining cores so I could do the rebuild at my leisure. He sold me ($50) a mixed set of turbo and non-turbo injectors, after measuring them and deciding it would work.

I don't think he's correct. I suspect the springs in the turbo injector bodies are stronger, and that no amount of shim removal is going to get me the required pop pressure.

Can you confirm or deny?

thanks!!

i am running my 300sdl on WVO with a Mercedessource dual tank system.

Has anyone had any experience good or bad with the following products:

Water Wetter-meant to cool operating temps by improving fluid dynamics of antifreeze/coolant mixture.

and

BG 44K-engine/fuel additive to be used in conjunction with diesel purge.

thanks.