I'm getting ready to put an order in for some parts and i'm getting all the part #'s together now. The vacuum line running from the T near the oil filter to the transmission modulater is broken and has been capped.(i don't know why) I'm sure this is the cause of my hard shifting and i'm going to replace the line, and the pin on the modulater. I've heard that the hose is 4mm but I just want to make sure. And if anybody has a part number that would be helpful as well. Thanks.

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1985 Mercedes 300DT

It's the same diameter as the rest of the vac lines on the car. I don't know the number. But you can measure any of the other ones.

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