My technique is rubbish.
Assemble - fit - test - mop up the mess
Reassemble - fit -test - mop upthe mess
Repeat until luck improves.

I've just had the same lack of succes on the new under stairs wc that
I've built. I don't know what I'm doing wrong. Maybe its that spongy
big coupling washer - or maybe it's the seal between the flush
assembly and the ceramic cistern. I'll go back and check when i've
finished sulking.

I put a smear of silicone around the nuts and washers thinking it
might help. Perhaps i shouldn't.
Could anyone give me pedantic step by step instructions please?

And ditto the small sink waste. Can't do it first time. Plughole,
waste/connection to trap. ***** slight drip from that too :-(

Many Thanks...

Bad mood!
Tony