O-ring purpose?

[35751]

I'm working on upgrading the guts of the tank on my 2004 R1150RT. There is an O-ring on the fuel sending unit. It's BMW part 16 14 2 306 645. What is the purpose and/or function of that O-ring? Thanks!

[BC1100S]

I'm suspecting it seals/retains whatever the sending unit plugs into at tbe bottom.

[bewareboy]

Here are a couple of pics from when I replace the in-tank fuel lines on my 04 R11150RT. I believe it is just to hold the vent and filler drain lines, not to seal anything. I did not change the installation and have had no problems since 2015 when I did this.
DSCI0872.jpgDSCI0869.jpg

[35751]

Here are a couple of pics from when I replace the in-tank fuel lines on my 04 R11150RT. I believe it is just to hold the vent and filler drain lines, not to seal anything. I did not change the installation and have had no problems since 2015 when I did this.
DSCI0872.jpgDSCI0869.jpg

Thanks, Jim. That makes sense. I should have been more attentive to the configuration when I pulled everything. Mike.