1988 560SL, need help
 

I hope this is an easy one. I have a 1988 560SL. I noticed a disconnected white vacuum line at the firewall at the back of the intake. I see it goes to the transmission modulator. I don't see anywhere to connect it to a vacuum source. I just replaced the front seal in the Trans and drove it around the block. Still leaking. Shifts poorly. I read that it's the front pump o- ring and gasket. 2nd time pulling it will be easier I suppose. Didn't like the wear on the torque converter where the seal contacts it, grooved somewhat. If anyone can advise me on anything I would be thankful. Otherwise the plan is to replace the front pump o-ring and gasket and try again. Thanks, Fred