Injector pump dripping

[AllenP]

I have a moderate leak (c. one drip per second) coming from the output side of my injector pump. I've checked the high pressure lines' flare nuts and all are snug, and the leak appears to be coming from a part in the center of the 4 fuel lines, about 28mm in diameter with three wrench flats on it 120º apart.

This part has a 12mm hex head bolt in its center and I checked that: it's tight and not leaking, and if I remove it I still can't budge the larger part (where I suspect the leak is) with tools I own.

Below are two photos, one showing where the leak is in general and one taken with an inspection mirrror showing the location more specifically.

Does anyone have experience with a leak here, or suggestions for whether this could be a DIY repair or should be addressed by a diesel pump specialist? This pump is in a VW, by the way; I'm posting here because there are other posts in this forum about my same engine & pump combination. Thanks!

 

[Suzuki_dude]

My pump had a leak around the bigger part in the middle. It's a 24mm. You can take a 24mm socket and grind every other flat curved to make a custom socket you'll never use again. It just comes out, change the o-ring, put it back. Idparts has a complete Bosch pump seal kit for $21. The little bolt in the middle I think is the plug for the hole where you put a dial indicator to time it. The seal kit will have that part too if needed.

 

[AllenP]

Thanks for these tips! I've ordered a socket and I'll look for a replacement o-ring in Viton.

 

[AllenP]

Wrap up and thanks:
The special socket came in the mail and I removed the center part the timing hole is in. Its seal had been compressed to an oblong cross-section and was stiff and cracked.
Unable to find a rebuild kit with Viton seals and unable to find design dimensions for the original seal, I first bought 1/2 dozen different o-rings that seemed close to the right size. Then I measured the old seal to find its cross-sectional area and measured the replacement candidates. One was a _very_ close match (same amount of rubber but with a round cross-section) so I tried installing this one first and it fit and the leak is gone!
Thanks to all for helping me be successful in my first foray into servicing an injector pump.