I took a look at my engine bay and have been unable to find what you are describing. I am sorry. I looked at two hoses that are at the back of the cylinder. They seem to be running off the vaccuum pump in the rear under the back seat. I am not sure which vaccuum line you are talking about. Do you have the air cleaner off? Do the vaccuum line(s) go into the intake plenum??
I'll do what I can if you give me a little more information.
Good luck brother!
Do you have pictures of your 2.6?
190E 2.6 - 244 000 km