Thanks for your reply John. I took the torbeck apart and the washer was flithy, leaving black marks all over my fingers. I inherited it with the house and it looked pretty old as it wasn't the extendable type so I decided to bin it and replace with a fluidmaster rather than try and repair it.
The new fluidmaster works fine but unfortunately there's a slight weep coming from the backnut under the cistern. I tightened it hand tight and then a quarter turn with a wrench as per instructions, it wept, so I tightened it a quarter turn more but it's still weeping.
Thing is, it's not progressing to a drip. I only know it's weeping cos if I rub some blue roll around it you can see a wet ring which has come from the outer ring of the backnut (there's nothing coming down the threads). But no matter how long you leave it, when you rub the blue roll round it's always a bit wet. I'm in 2 minds about taking it apart and starting again or leaving it, as I say, it's a weep rather than a drip. Might it seal itself or is that wishful thinking?
It was the standard fluidmaster 400 I used, and it comes with a standard flat washer for inside the base of the cistern, yet it seems the Pro45 comes with a conical washer, like the old Torbeck I took off which never wept at all. Is it worth sourcing a conical washer, or should I maybe add a washer underneath the outside of the cistern, above the backnut?
