Lever flush cistern parts list

johnscts said:

So what you are saying the clamping plate does not compress the doughnut

Click to expand...

Yes, it compresses the washer onto the pan

The rubber gasket that goes onto the tailpipe of the flush valve, before it is pushed through the cistern outlet, creates a watertight seal between the flush valve and the cistern, when the plate and backnut is connected and secured tightly - to stop water leaking out of the cistern when it's full.
The donut washer stops water leaking out between the cistern and the pan "during a flush".

Many thanks for the link just looked at the link and it looks as though the plate screws directly on
To the cistern ceramic base ( no nylon washer) I have to say thank you for all your patience and help. I am sure in the very distant past a clamped the doughnut to the plate which was a mistake. Looking at the YouTube link the place your man replaced was well corroded ( no Vaseline or silicon grease used previously. ps I don’t quite know how I add to your points but your help was 10/10
Kind regards john