200tdi oil return pipe

I've been searching on and off for months and can't find a part number for the above. Just so I'm clear its the pipe that goes from the rocker cover back down into the sump (I think) hopefully you'll know the one I mean anyway. I've been losing oil like a bitch and I reckon this has got a split in it somewhere. Cleaned all of this side of the engine off and it gets filthy again very quickly but doesn't leave any stains when parked so I can only assume it leaks when running.

If anyone could point me in the right direction it would be much appreciated

pipe that goes from bottom of cyclone to sump is err1605,hose from rocker cover to cam gallery plate behind injection pump is err877

Should have said it's a disco engine but I imagine they would be the same

Ah just saw that reply. Cheers James