There is a very slight leak from where the flush pipe joins the toilet,have tried sealing it with silicone, to no avail.Looks like there may be a slight crack on the porcelain, is there any putty or sealant to fix this or is it a new toilet job?

RP, February 2010

It doesn't have wing nuts, there is a clear donut mansher which sits in the toilet inlet and buts up against the back of the toilet, the leak is coming from the toilet body, rather than the washer. I've tried silicone ,but it doesn't stop it.

RP, February 2010

you need to replace internal or external flush cone buy from any diy store

del, February 2010

The down pipe from the syphon unit in the cistern enters a hole in the pan. The seal between the two is made by squeezing a large soft washer - donut washer. The water is low pressure and the seal is made by pulling a metal plate down onto the washer. Two wing nuts one each side pointing down at the very back of the pan apply the force. You can often fix a leak here by just tightening the wing nuts.

Squint along from the side - the washer should just be visible as a thin black line and it should be parallel. If it's thinner at the front than it is at the back then the syphon tube may be interfereing with the pan in which case a good seal will be difficult to achieve. You fix this by sawing a few mm from the end of the pipe.

To replace the donut you need to isolate the water - flush the toilet - remove the wing nuts - disconnect the water supply to the cistern and remove two screws holding it to the wall - then gently lift off upwards. Tip any remaining water into the pan. A 20 minute job.

New donut washers may be had from a DIY store and often come with a compression plate.

Others say to use silicone to help make a good seal but if it all sits square and the plate is pulled down well you should not need to.

Do not overtighten the wall screws on reassembly else the cistern may crack.

Good luck...

Peccavi, February 2010