Surprise oil leak - help

[RobinLegin]

The straight bit was mildly proud and protrudes above the metal. I think the leak came from where the D cup 'saddles the metal over the curve.
Nigel

[milothedog]

The straight bit was mildly proud and protrudes above the metal. I think the leak came from where the D cup 'saddles the metal over the curve.
Nigel

If the bit that goes across the top of the half moon rubber is not level with the rest of the mating face of the cover it will not push the rubber in to the saddle to form a seal when tightened down.