The flush mechanism on our close coupled WC has begun to fail so I set about replacing it, as I have done in another WC in the house, with one of the Fluidmaster button press devices. Not making the same mistakes as last time, I ensured I had a close coupling bracket / donut available, and also decided to replace the fill valve too as the old one had had a few wobbles recently.

When taking off the cistern I had a bugger of a time getting the inbound water supply disconnected from the fill valve in the cistern as the water-side threaded connector was almost impossible to reach, but in the end I managed to get it out by unscrewing the part inside the cistern, which was very effective.

In reverse, this is causing me some problems. I seem to have managed to get the threaded connection to the water supply "dry" through lots of small movements and fiddly twisting.

But the seal on the cistern side of things is persistently dripping a small amount.

The instructions tell me not to tighten the back nut more than 1/4 beyond hand tight, but that feels too loose, and definitely drips. I've then progressively tightened it up, but there's still a small drip. Should I just continue with tightening, or is this likely to be a case of reversing everything I have done, remove the cistern again and re-seat the rubber seal inside the cistern?

Matt