Close Coupled Cistern Leak

[Steve]

I had a problem with the flush handle not returning on a 20 year old close coupled cistern. I renewed the syphon assembly and the thick rubber ring that sits between the cistern and the toilet pan - the old one was perished.

All was well for a couple of weeks but now every time it is flushed a small quantity of water (perhaps a few teaspoons full) leaks from the joint between the cistern and pan.

I've never done this before. It's a bit of a faff taking it all apart again so before I do, does anybody have any idea what I might have done wrong? Should I have put some kind of silicone grease on the rubber ring? or do they come in different sizes? in which case I might have the wrong size.

TIA

Steve

[The Medway Handyman]

Its more a case of they come in 2 types IME. One has a rounded over top & the other is flat.

Since its a small leak, try some Plumbers Mait around the ring.

Make sure the wing nuts are done up tight.

[Andrew Gabriel]

If there's any movement between the two parts, that will do it. The doughnut washer takes up the shape of the cavity it's squashed into, and movement will make it leak, probably in the timeframe you've seen.

I suggest getting a fresh doughnut washer before taking it apart. It shouldn't need any sealant.

[The Medway Handyman]

The OP has replaced it.

Famous last words :-)