E300 D 1996 Big trouble Fuel leak

[radunegru]

I decided to change the fuel lines and the injection line seals on my 1996 E300D (with 120K miles) because of a major fuel leak that was going on for few months.
I did purchase all lines, filter, prefilter, copper and rubber seals.
The job went smooth( it was not the first time). All is back together, car started no problem in about 30 sec of cranking.
After warm up I did took it for a spin....all great, and then I parked the car.
After 2 hours I discover a puddle of Diesel under the car.
Check every think and find out that diesel is leaking from the front driver side of the pump.See attached picture.What is that part that is connected with two fuel lines on the top and one on the bottom?