I think that is what you call it. I know i am going to have to pull the pump to replace that oring. I was just wondering if you just take the Pin out and thats it to get to the oring. I checked the sticky but it didn't go into reference on that part. Just don't want to mess anything up. Here is a picture of the leak.

 

You can unscrew that plug without removing anything else and change the o-ring. I think there is a spring or something in there, so just be careful while removing.

Aaron

 

Very easy to replace. Just did it yesterday in fact. Just use the appropriate O-ring from the Bosch seal kit. It only takes a couple of minutes to do the job. That was the one O-ring that I forgot to replace when I did the full reseal, and it reminded me by leaving a puddle of diesel under the truck.