Toilet cistern wont stop leaking?

[Mr Sparkle]

My friends closed couple toilet would leak whenever it was flushed

So i replaced the 2" doughnut and cistern bolts

This stopped the leak for a few days but now she says that it is leaking again. She cannot pinpoint the leak, apart from 'it's coming from the bottom of cistern again'

I now plan to replace all of the parts that I can e.g. flush valve, fill valve, new doughnut, water isolator and toilet water connector

When putting the new parts together, can I get some advice of some of the techniques to avoid leaks?

For example use silicone or ptfe tape in certain places

 

[terryplumb]

Replacing all those parts without knowing the actual cause of the leak is a bit pointless . Establish what is leaking and put that right.

 

[blup]

The bolts can cause leaking if overtightened or under tightened.

Also the way the doughnut sits on the pan. Did you use boss white or other sealant when fitting the new doughnut?

If the toilet is cracked that's another matter.

Blup

 

[zebedee2001]

Are you sure it isn't just condensation off the cistern?

 

[blup]

Possibly, a piece of kitchen roll underneath will clarify that.

Blup

 

[oldbuffer]

Could also be the inlet valve leaking where it goes through the cistern, if bottom fill.