What is a leaking 13 pin connector on 1999 Mercedes-Benz E320

What is a leaking 13 pin connector.
What should control arm bushings cost to replace?

Asked by for the 1999 Mercedes-Benz E320
The front bushings are about $70 and 1.5 hours to replace according to my labor guide. If the steering then requires alignment that would incur an additional charge.
I've never heard of a "leaking 13 pin connector".