A Bosch fuel injection shop told me a new o-ring will not stop the leak if the bushing is worn.
Yep of course they would tell you that.

If a pump has a leak and a lot of slop in the bush - I'll replace the whole lot
But if I'm just gov-modding a pump (4 this week) I want to bung in a new seal regardless.
The post is not about the leaking - it's what size the o-ring is.
I went out and picked through the leftovers from a few Bosch kits and I have that O-ring, so to make things right, I'll happily send it off to you, if you can manage a week or so downtime.
Cheers for the offer - no downtime issue, Im building pumps for other people. If you could measure the ID and cross section I'd be very grateful.
Should be 6mm ID & 2mm cross-section.
Now, that makes a lot more sense. Thanks.