Bosch injector pump on MD7A Volvo Penta leaking

[Sailing newbie selsey]

Hi all, I have an old Volvo Penta MD7A which has a Bosch injection pump. It has developed a leak from the large bolt on the front face below the injection pipe couplings. I can not find the serial number for the pump on it, the plate is no longer there! Trying to find some sort of diagram for the pump online is proving impossible, it may just be a simple washer that has gone on the back of the large bolt, but before I unscrew it just wondered if anyone knows what the bolt in question does?
thanks alll

 

[Bilgediver]

It looks like a bleed screw and probably has a copper washer. Is the bolt tight. Screw it out slowly while inspecting the threads as they emerge out of the cover. Iwould expect to see a hole in the threads before the screw comes right out.

Annealing the copper washer by heating to red heat and plunging into cold water should soften it and stop the drips.

 

[penfold]

Part 44. "washer" 243557 isn't available anymore, but it's not obvious whether it's setting a clearance or just a sealing washer, if the latter then any copper washer that is the right size should do, or anneal the existing washer(if copper) and refit.