is this what I have fittted to my A1? presumably oil flows out of block into the RH arm, pushes the oil pressure plate out the way and out of the top arm (as in photo).
what is the cap with the nut for - does it undo, and if undone, what is inside? (I am guessing it is to allow the housing to be drilled)
apologies - not had a good enough look in that area.
So many questions - so little time
Oil does indeed flow up through the bit opposite the pressure switch then past the plastic switch out into the oil passage along the rear of the cylinders - up the block. Inside is just a view of the switch siting on the seat of the unit.
The nut may be to check flow - it could be a blank (as you guess) but as its a cast item, seems unlikely?
And on the 7th day... Zeds were created!