Cuban8
Before you go any further be sure that it is not the injector pipe connection (at the swaging) that is leaking.

On the Bosch MW pump fitted to your model there are only two other possible sources of a leak.

1) The copper washer between the delivery valve and the metering element.
2) The lapped faces that “wring” together between the del. valve body and the pipe connector/spring housing (i.e. the long hex. sleeve)

Both of these must hold a pressure of <1800psi.

Sometimes you can be lucky if you do not disturb the del. valve body and it will not leak but if it does as in your case then the copper washer must be replaced and thoroughly cleaned out.

The del. valve body is best lifted out with a magnet, you can also use a thin wire and hook it out from under – Keep away from the chamfer where it seals, new D valves are expensive!

You will have to get a new copper washer from a Bosch agent – 15mm x 10mm x 0.5mm thick, don’t use a substitute.

The lapped faces of the del. valve and the valve spring housing (i.e the long hex sleeve) can be cleaned using a piece of plain paper on plate glass with silver polish. Don’t even THINK about using abrasive paper!

To re-assemble: Tighten to 30Nm and release. Again to 30Nm and release then finally to 48Nm. The purpose of this is to ensure the lapped faces are seated squarely and wrung together before final tightening. Always use two wrenches when tightening injector pipe sleeve nut.

BTW - The thread is parallel not tapered and there are no “O’ rings in the MW pump del. valve assy.

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Beagle